S&S FINAL DRAFT

                            UNITED AIR LINES, INC.


                                      and


                      STATE STREET BANK AND TRUST COMPANY
                     OF CONNECTICUT, National Association,
                                  as Trustee



                       --------------------------------



                         PASS THROUGH TRUST AGREEMENT

                         Dated as of February 1, 1992,
                            As Amended And Restated
                               as of May 1, 1995


                       --------------------------------

 
                               TABLE OF CONTENTS


     Section                                                     Page
     -------                                                     ----


                                   ARTICLE I

                                  DEFINITIONS

 
     1.01.  Definitions...........................................  2
     1.02.  Compliance Certificates and Opinions.................. 11
     1.03.  Form of Documents Delivered to Trustee................ 11
     1.04.  Acts of Certificateholders............................ 12

                                  ARTICLE II

                      ORIGINAL ISSUANCE OF CERTIFICATES;
                        ACQUISITION OF EQUIPMENT NOTES

 
     2.01.  Amount Unlimited; Issuable in Series.................. 14
     2.02.  Acquisition of Equipment Notes........................ 16
     2.03.  Acceptance by Trustee................................. 17
     2.04.  Limitation of Powers.................................. 18

                                  ARTICLE III

                               THE CERTIFICATES
 
     3.01.  Form, Denomination and Execution of Certificates...... 18
     3.02.  Authentication of Certificates........................ 19
     3.03.  Temporary Certificates................................ 19
     3.04.  Registration of Transfer and Exchange of Certificates. 20
     3.05.  Mutilated, Destroyed, Lost or Stolen Certificates..... 20
     3.06.  Persons Deemed Owners................................. 21
     3.07.  Cancellation.......................................... 21
     3.08.  Limitation of Liability for Payments.................. 21
     3.09.  Book-Entry and Definitive Certificates................ 21
 

 
                                      ii

                                  ARTICLE IV

                         DISTRIBUTIONS; STATEMENTS TO
                              CERTIFICATEHOLDERS
     4.01.  Certificate Account and Special Payments Account...... 24
     4.02.  Distributions from Certificate Account and Special 
             Payments Account..................................... 24
     4.03.  Statements to Certificateholders...................... 26
     4.04.  Investment of Special Payment Moneys.................. 26

                                   ARTICLE V

                                  THE COMPANY

     5.01.  Maintenance of Corporate Existence.................... 27
     5.02.  Consolidation, Merger, etc............................ 27

                                  ARTICLE VI

                                    DEFAULT

 
     6.01.  Events of Default..................................... 28
     6.02.  Incidents of Sale of Equipment Notes.................. 29
     6.03.  Judicial Proceedings Instituted by Trustee; 
             Trustee May Bring Suit............................... 29
     6.04.  Control by Certificateholders......................... 30
     6.05.  Waiver of Past Defaults............................... 30
     6.06.  Right of Certificateholders to Receive Payments 
             Not to Be Impaired................................... 31
     6.07.  Certificateholders May Not Bring Suit Except Under 
             Certain Conditions................................... 31
     6.08.  Remedies Cumulative................................... 32

                                  ARTICLE VII

                                  THE TRUSTEE
 
     7.01.  Notice of Defaults.................................... 32
     7.02.  Certain Rights of Trustee............................. 33
     7.03.  Not Responsible for Recitals or Issuance of 
             Certificates......................................... 34
     7.04.  May Hold Certificates................................. 34
     7.05.  Money Held in Trust................................... 34
     7.06.  Compensation and Reimbursement........................ 34
     7.07.  Corporate Trustee Required; Eligibility............... 35
     7.08.  Resignation and Removal; Appointment of Successor..... 36

 
                                      iii

     7.09.  Acceptance of Appointment by Successor................ 38
     7.10.  Merger, Conversion, Consolidation or Succession 
             to Business.......................................... 38
     7.11.  Maintenance of Agencies............................... 39
     7.12.  Money for Certificate Payments to Be Held in Trust.... 40
     7.13.  Registration of Equipment Notes in Trustee's Name..... 40
     7.14.  Representations and Warranties of Trustee............. 41
     7.15.  Withholding Taxes; Information Reporting.............. 41
     7.16.  Trustee's Liens....................................... 42
 
                                 ARTICLE VIII

               CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE
 
     8.01.  The Company to Furnish Trustee with Names and
             Addresses of Certificateholders...................... 42
     8.02.  Preservation of Information; Communications to
             Certificateholders................................... 43
     8.03.  Reports by Trustee.................................... 43
     8.04.  Reports by the Company................................ 43
 

                                   ARTICLE IX

                            SUPPLEMENTAL AGREEMENTS
 
     9.01.  Supplemental Agreements Without Consent of 
             Certificateholders................................... 44
     9.02.  Supplemental Agreements with Consent of 
             Certificateholders................................... 45
     9.03.  Documents Affecting Immunity or Indemnity............. 46
     9.04.  Execution of Supplemental Agreements.................. 46
     9.05.  Effect of Supplemental Agreements..................... 46
     9.06.  Conformity with Trust Indenture Act................... 46
     9.07.  Reference in Certificates to Supplemental Agreements.. 47
 
                                   ARTICLE X

                  AMENDMENTS TO INDENTURE AND NOTE DOCUMENTS

     10.01.  Amendments and Supplements to Indenture and Other Note
              Documents........................................... 47

 
                                      iv


                                  ARTICLE XI

                             TERMINATION OF TRUSTS

     11.01.  Termination of the Trusts............................  47


                                  ARTICLE XII
                           MISCELLANEOUS PROVISIONS

 
     12.01.  Limitation on Rights of Certificateholders...........  49
     12.02.  Certificates Nonassessable and Fully Paid............  49
     12.03.  Notices..............................................  49
     12.04.  Governing Law........................................  50
     12.05.  Severability of Provisions...........................  51
     12.06.  Trust Indenture Act Controls.........................  51
     12.07.  Effect of Headings and Table of Contents.............  51
     12.08.  Successors and Assigns...............................  51
     12.09.  Benefits of Agreement................................  51
     12.10.  Legal Holidays.......................................  51
     12.11.  Counterparts.........................................  51
 
Exhibit A  -  Form of Certificate
 

 
     This PASS THROUGH TRUST AGREEMENT, dated as of February 1, 1992, as amended
and restated as of May 1, 1995, between United Air Lines, Inc., a Delaware
corporation, and State Street Bank and Trust Company of Connecticut, National
Association, a national banking association, as Trustee, is made with respect to
the formation from time to time of separate United Air Lines Pass Through
Trusts, and the issuance from time to time of separate series of Pass Through
Certificates representing fractional undivided interests in the respective
Trusts.

     WITNESSETH:

     WHEREAS, from time to time the Company (this and certain other defined
terms used herein are defined in Section 1.01) may enter into a Trust Supplement
with the Trustee named therein pursuant to which such Trustee shall declare the
creation of a separate Trust for the benefit of the Holders of the series of
Certificates to be issued in respect of such Trust, and the initial Holders of
the Certificates of such series, as the grantors of such Trust, by their
respective acceptances of the Certificates of such series, shall join in the
creation of such Trust with the Trustee;

     WHEREAS, all Certificates to be issued in respect of each separate Trust
will be issued as a separate series pursuant to this Agreement, will evidence
fractional undivided interests in such Trust and will have no rights, benefits
or interests in respect of any other separate Trust or the property held
therein;

     WHEREAS, from time to time, pursuant to the terms and conditions of this
Agreement with respect to each separate Trust formed hereunder, the Trustee on
behalf of such Trust shall purchase one or more issues of Equipment Notes having
the same interest rate as, and final maturity dates not later than the final
Regular Distribution Date of, the series of Certificates issued in respect of
such Trust and shall hold such Equipment Notes in trust for the benefit of the
Certificateholders of such Trust;

     WHEREAS, to facilitate the sale of Equipment Notes to, and the purchase of
Equipment Notes by, the Trustee on behalf of each Trust created from time to
time pursuant to this Agreement, the Company has duly authorized the execution
and delivery of this Basic Agreement and each Trust Supplement as the "issuer",
as such term is defined in and solely for purposes of the Securities Act of
1933, as amended, of the Certificates to be issued in respect of each Trust and
as the "obligor", as such term is defined in and solely for purposes of the
Trust Indenture Act of 1939, as amended, with respect to all such Certificates
and is undertaking to perform certain administrative and ministerial duties
hereunder and is also undertaking to pay the fees and expenses of the Trustee;

     WHEREAS, this Basic Agreement, as amended or supplemented from time to
time, is subject to the provisions of the Trust Indenture Act of 1939, as
amended, and shall, to the extent applicable, be governed by such provisions;

 
                                       2

     WHEREAS, State Street Bank and Trust Company of Connecticut, National
Association ("State Street"), as Trustee, and United Air Lines, Inc. wish to
effect certain corrections and supplements, none of which are material or
adversely affect the interests of the Certificateholders of any series, to this
Basic Agreement as originally executed and delivered;

     NOW THEREFORE, in consideration of the mutual agreements herein contained,
and of other good and valuable consideration the receipt and adequacy of which
are hereby acknowledged, the parties hereto agree (and agree that this Basic
Agreement is hereby amended and restated to read) as follows:


                                   ARTICLE I

                                  DEFINITIONS

     Section 1.01.  Definitions.  For all purposes of this Basic Agreement,
                    -----------                                            
except as otherwise expressly provided or unless the context otherwise requires:

          (1) the terms used herein that are defined in this Article have the
     meanings assigned to them in this Article, and include the plural as well
     as the singular;

          (2) all other terms used herein which are defined in the Trust
     Indenture Act, either directly or by reference therein, have the meanings
     assigned to them therein;

          (3) all references in this Basic Agreement to designated "Articles",
     "Sections" and other subdivisions are to the designated Articles, Sections
     and other subdivisions of this Basic Agreement;

          (4) the words "herein", "hereof" and "hereunder" and other words of
     similar import refer to this Basic Agreement as a whole and not to any
     particular Article, Section or other subdivision; and

          (5) the term "this Agreement" (as distinguished from "this Basic
     Agreement") refers, unless the context otherwise requires, to this Basic
     Agreement as supplemented by the Trust Supplement creating a particular
     Trust and establishing the series of Certificates issued or to be issued in
     respect thereof, with reference to such Trust and each series of
     Certificates, as this Basic Agreement as so supplemented may be further
     supplemented with respect to such Trust and such series of Certificates.

 
                                       3


          Act:  With respect to any Certificateholder has the meaning specified
          ---                                                                  
     in Section 1.04.

          Affiliate:  With respect to any specified Person, means any other
          ---------                                                        
     Person directly or indirectly controlling or controlled by or under direct
     of indirect common control with such Person.  For the purposes of this
     definition, "control", when used with respect to any specified Person,
     means the power to direct the management and policies of such Person,
     directly or indirectly, whether through the ownership of voting securities,
     by contract or otherwise, and the terms "controlling" and "controlled" have
     meanings correlative to the foregoing.

          Aircraft:  Means an aircraft, including engines therefor, owned by or
          --------                                                             
     leased to the Company and securing one or more Equipment Notes.

          Authorized Agent:  With respect to the Certificates of any series,
          ----------------                                                  
     means any Paying Agent or Registrar for the Certificates of such series.

          Basic Agreement:  Means this Pass Through Trust Agreement, as the same
          ---------------                                                       
     may from time to time be supplemented, amended or modified, but does not
     include any Trust Supplement.

          Book-Entry Certificates:  With respect to the Certificates of any
          -----------------------                                          
     series, means a beneficial interest in the Certificates of such series,
     ownership and transfers of which shall be made through book entries by a
     Clearing Agency as described in Section 3.09.

          Business Day:  With respect to the Certificates of any series, means
          ------------                                                        
     any day other than a Saturday, a Sunday or a day on which commercial banks
     are required or authorized to close in Chicago, Illinois, New York, New
     York; and, so long as any such Certificate is outstanding, a city and state
     in which the Trustee or any related Loan Trustee maintains its Corporate
     Trust Office or receives and disburses funds.

          Certificate:  Means any one of the certificates executed and
          -----------                                                 
     authenticated by the Trustee, substantially in the form of Exhibit A
     hereto.

          Certificate Account:  With respect to the Certificates or any series,
          -------------------                                                  
     means the account or accounts created and maintained for such series
     pursuant to Section 4.01(a) and the related Trust Supplement.

          Certificateholder or Holder:  With respect to the Certificates of any
          ---------------------------                                          
     series, means the Person in whose name a Certificate of such series is
     registered in the Register for Certificates of such series.

 
                                       4


          Certificate Owner:  With respect to the Certificates of any series, 
          -----------------
     means, for purposes of Section 3.09, the Person who owns a Book Entry 
     Certificate of such series.

          Clearing Agency:  Means an organization registered as a "clearing
          ---------------                                                  
     agency" pursuant to Section 17A of the Securities Exchange Act of 1934, as
     amended.

          Clearing Agency Participant:  Means a broker, dealer, bank, other
          ---------------------------                                      
     financial institution or other Person for whom from time to time a Clearing
     Agency effects, directly or indirectly, book-entry transfers and pledges of
     securities deposited with the Clearing Agency.

          Company:  Means United Air Lines, Inc., a Delaware corporation, or its
          -------                                                               
     successor in interest pursuant to Section 5.02, or any other obligor with
     respect to the Certificates (within the meaning of the Trust Indenture
     Act).

          Corporate Trust Office:  With respect to the Trustee or any Loan
          ----------------------                                          
     Trustee, means the office of such trustee in the city at which at any
     particular time its corporate trust business shall be principally
     administered.

          Cut-off Date:  With respect to the Certificates of any series, means
          ------------                                                        
     the date designated as such in this Agreement.

          Definitive Certificates:  With respect to the Certificate of any
          -----------------------                                         
     series, has the meaning specified in Section 3.09.

          Direction:  Has the meaning specified in Section 1.04(c).
          ---------                                                

          Equipment Note:  With respect to the Certificates of any series, has
          --------------                                                      
     the meaning given to "Certificate" in the related Indenture.

          ERISA:  Means the Employee Retirement Income Security Act of 1974, as
          -----                                                                
     amended from time to time, or any successor federal statute.

          Escrow Account:  With respect to the Certificates of any series, has
          --------------                                                      
     the meaning specified in Section 2.02(b).

          Escrowed Funds:  With respect to any Trust, has the meaning specified
          --------------                                                       
     in Section 2.02(b).

 
                                       5

          Event of Default:  Means, in respect of any Trust, the occurrence of
          ----------------                                                    
     an Indenture Default under any Indenture pursuant to which Equipment Notes
     held by such Trust were issued.

          Fractional Undivided Interest:  Means the fractional undivided
          -----------------------------                                 
     interest in a Trust that is evidenced by a Certificate relating to such
     Trust.

          Indenture:  With respect to any Trust, means each of the one or more
          ---------                                                           
     separate trust indenture and security agreements or trust indentures and
     mortgages or similar agreements described in, or on a schedule attached to,
     this Agreement which relates to an issue of Equipment Notes to be held in
     such Trust and an indenture having substantially the same terms and
     conditions as such trust indenture and security agreement and which relates
     to a Substitute Aircraft; as each such agreement may be amended or
     supplemented in accordance with its respective terms; and Indentures means
                                                               ----------      
     all of such agreements.

          Indenture Default:  With respect to any Indenture, means any Indenture
          -----------------                                                     
     Event of Default (as such term is defined in such Indenture).

          Initial Regular Distribution Date:  With respect to the Certificates
          ---------------------------------                                   
     of any series, means the first Regular Distribution Date on which a
     Scheduled Payment is to be made.

          Issuance Date:  With respect to the Certificates of any series, means
          -------------                                                        
     the date of the issuance of such Certificates.

          Lease:  Means any lease between an Owner Trustee, as the lessor, and
          -----                                                               
     the Company, as the lessee, referred to in the related Indenture, as each
     such lease may be amended or supplemented in accordance with its respective
     terms; and Leases means all such Leases.
                ------                       

          Letter of Representations:  With respect to the Certificates of any
          -------------------------                                          
     series, means the agreement among the Company, the Trustee and the initial
     Clearing Agency substantially in the form attached as an Exhibit to the
     related Trust Supplement.

          Loan Trustee:  With respect to any Equipment Note or the Indenture
          ------------                                                      
     applicable thereto, means the bank or trust company designated as loan
     trustee under such Indenture; and any successor to such Loan Trustee as
     such trustee; and Loan Trustees means all of the Loan Trustees under the
                       -------------                                         
     Indentures.

 
                                       6

          Note Documents:  With respect to any Equipment Note, means the related
          --------------                                                        
     Indenture, Note Purchase Agreement, and if the related Aircraft is leased
     to the Company, the related Lease and the related Owner Trustee's Purchase
     Agreement.

          Note Purchase Agreement:  With respect to the Certificates of any
          -----------------------                                          
     series, means any note purchase, participation or similar agreement
     providing for, among other things, the purchase of Equipment Notes by the
     Trustee on behalf of the relevant Trust; and Note Purchase Agreements means
                                                  ------------------------      
     all such agreements.

          Officer's Certificate:  Means a certificate signed, (a) in the case of
          ---------------------                                                 
     the Company, by (i) the Chairman of the Board of Directors, the President
     or any Senior Vice President of the Company, signing alone or (ii) any Vice
     President of the Company signing together with the Secretary, the Assistant
     Secretary, the Treasurer or any Assistant Treasurer of the Company or, (b)
     in the case of an Owner Trustee or a Loan Trustee, a Responsible Officer of
     such Owner Trustee or such Loan Trustee, as the case may be.

          Opinion of Counsel:  Means a written opinion of legal counsel who (a)
          ------------------                                                   
     in the case of counsel for the Company may be (i) a senior attorney in rank
     of the officers of the Company a principal duty of which is furnishing
     advice as to legal matters, (ii) Vedder, Price, Kaufman & Kammholz or (iii)
     such other  counsel designated by the Company and reasonably acceptable to
     the Trustee and (b) in the case of any Owner Trustee or any Loan Trustee
     may be such counsel as may be designated by any of them whether or not such
     counsel is an employee of any of them, and who shall be reasonably
     acceptable to the Trustee.

          Outstanding:  With respect to Certificates of any series, means, as of
          -----------                                                           
     the date of determination, all Certificates of such series theretofore
     authenticated and delivered under this Agreement, except:

               (i) Certificates of such series theretofore cancelled by the
          Registrar or delivered to the Trustee or the Registrar for
          cancellation;

               (ii) All of the Certificates of such series if money in the full
          amount required to make the final distribution with respect to such
          series pursuant to Section 11.01 hereof has been theretofore deposited
          with the Trustee in trust for the Holders of the Certificates of such
          series as provided in Section 4.01 pending distribution of such money
          to such Certificateholders pursuant to such final distribution
          payment; and

 
                                       7

               (iii)   Certificates of such series in exchange for or in lieu of
          which other Certificates of such series have been authenticated and
          delivered pursuant to this Basic Agreement.

          Owner Participant:  With respect to any Equipment Note, means the
          -----------------                                                
     "Owner Participant", if any, as referred to in the Indenture pursuant to
     which such Equipment Note is issued and any permitted successor or assign
     of such Owner Participant; and Owner Participants at any time of
                                    ------------------               
     determination means all of the Owner Participants thus referred to in the
     Indentures.

          Owner Trustee:  With respect to any Equipment Note, means the "Owner
          -------------                                                       
     Trustee", if any, as referred to in the Indenture pursuant to which such
     Equipment Note is issued, not in its individual capacity but solely as
     trustee; and Owner Trustees means all of the Owner Trustees party to any of
                  --------------                                                
     the respective Indentures.

          Owner Trustee's Purchase Agreement:  With respect to the certificates
          ----------------------------------                                   
     of any series, if the related Aircraft is leased to the Company, has the
     meaning specified therefor in the related Lease.

          Paying Agent:  With respect to the Certificates of any series, means
          ------------                                                        
     the paying agent maintained and appointed for the Certificates of such
     series pursuant to Section 7.11.

          Permitted Investments:  Means obligations of the United States of
          ---------------------                                            
     America or agencies or instrumentalities thereof for the payment of which
     the full faith and credit of the United States of America is pledged,
     maturing in not more than 60 days or such lesser time as is necessary for
     payment of any Special Payments on a Special Distribution Date.

          Person:  Means an person, including any individual, corporation,
          ------                                                          
     partnership, joint venture, association, joint stock company, trust,
     unincorporated organization, or government or any agency or political
     subdivision thereof.

          Pool Balance:  With respect to any Trust, means as of any date the
          ------------                                                      
     aggregate unpaid principal amount of the Equipment Notes held in such Trust
     on such date plus the amount of the principal payments on such Equipment
     Notes held by the Trustee and not yet distributed plus the amount of any
     moneys held in the related Escrow Account (other than earnings thereon).
     The Pool Balance as of any Regular Distribution Date or Special
     Distribution Date with respect to such Trust shall be computed after giving
     effect to the payment of principal, if any, on such Equipment Notes and
     distribution thereof to are made on that date.

 
                                       8

          Pool Factor:  With respect to any Trust, means as of any date the
          -----------                                                      
     quotient (rounded to the seventh decimal place) computed by dividing (i)
     the Pool Balance as at such date by (ii) the aggregate original principal
     amount of the Certificates of such Trust.  The Pool Factor as of any
     Regular Distribution Date or Special Distribution Date with respect to such
     Trust shall be computed after giving effect to the payment of principal, if
     any, on such Equipment Notes and distribution thereof to be made on that
     date.

          Postponed Notes:  With respect to any Trust or the related series of
          ---------------                                                     
     Certificates, means the Equipment Notes to be held in such Trust as to
     which a Postponement Notice shall have been delivered pursuant to Section
     2.02(b).

          Postponement Notice:  With respect to any Trust or the related series
          -------------------                                                  
     of Certificates, means an Officer's Certificate of the Company signed by an
     officer of the Company (1) requesting that the Trustee temporarily postpone
     purchase of the related Equipment Notes to a date later than the Issuance
     Date of such series of Certificates, (2) identifying the amount of the
     purchase price of each such Equipment Note and the aggregate purchase price
     for all such Equipment Notes, (3) setting forth the reasons for such
     postponement and (4) with respect to each such Equipment Note, either (a)
     setting or resetting a new Transfer Date (which shall be on or prior to the
     applicable Cut-off Date) for payment by the Trustee of such purchase price
     and issuance of the related Equipment Note, or (b) indicating that such new
     Transfer Date (which shall be on or prior to the applicable Cut-off Date)
     will be set by subsequent written notice not less than one Business Day
     prior to such new Transfer Date.

          Record Date:  With respect to any Trust or the related series of
          -----------                                                     
     Certificates, means (i) for Scheduled Payments to be distributed on any
     Regular Distribution Date, other than the final distribution, with respect
     to such series, the 15th day (whether or not a Business Day) preceding such
     Regular Distribution Date, and (ii) for Special Payments to be distributed
     on any Special Distribution Date, other than the final distribution, with
     respect to such series, the 15th day (whether or not a Business Day)
     preceding such Special Distribution Date.

          Register and Registrar:  With respect to the Certificates of any
          ----------------------                                          
     series, mean the register maintained and the registrar appointed for such
     series pursuant to Sections 3.04 and 7.11.

          Regular Distribution Date:  With respect to distributions of Scheduled
          -------------------------                                             
     Payments in respect of any series of Certificates, means each date
     designated as such in this Agreement, until payment of all the Scheduled
     Payments to be made under the Equipment Notes held in such Trust has been
     made.

 
                                       9

          Request:  Means a request by the Company setting forth the subject
          -------                                                           
     matter of the request accompanied by an Officer's Certificate and an
     opinion of Counsel as provided in Section 1.02 of this Basic Agreement.

          Responsible Officer:  With respect to any Trustee, any Loan Trustee
          -------------------                                                
     and any Owner Trustee, means any officer in the Corporate Trust  ?
     Department of the Trustee, Loan Trustee or Owner Trustee or any other
     officer customarily performing functions similar to those performed by the
     persons who at the time shall be such officers, respectively, or to whom
     any corporate trust matter is referred because of his knowledge of and
     familiarity with a particular subject.

          Scheduled Payment:  With respect to any Equipment Note, means any
          -----------------                                                
     payment (other than a Special Payment) of interest on or principal of and
     interest on an Equipment Note due from the obligor thereon which
     installment represents the installment of principal at the stated maturity
     of such installment of principal on such Equipment Note or the payment of
     regularly scheduled interest accrued on the unpaid principal amount of such
     Equipment Note, or both.

          SEC:  Means the Securities and Exchange Commission, as from time to
          ---                                                                
     time constituted or created under the Securities Exchange Act of 1934, or,
     if at any time after the execution of this instrument such Commission is
     not existing and performing the duties now assigned to it under the Trust
     Indenture Act, then the body performing such duties on such date.

          Special Distribution Date:  With respect to the Certificates of any
          -------------------------                                          
     series, means each date on which a Special Payment is to be distributed as
     specified in this Agreement.

          Special Payment:  With respect to a Special Distribution Date in
          ---------------                                                 
     respect of the Certificates of any series, means (i) any payment of
     principal of, premium, if any, and interest resulting from the redemption
     or purchase of an Equipment Note held in the applicable Trust, (ii) any
     payment of principal of and interest (including any interest accruing upon
     default) on, or any other amount in respect of, any such Equipment Note
     upon an Indenture Default in respect thereof or upon an acceleration under
     the Indenture relating thereto, (iii) the amounts required to be
     distributed in respect thereof pursuant to the last paragraph of Section
     2.02(b), (iv) the amounts required to be distributed in respect thereof
     pursuant to the penultimate paragraph of Section 2.02(b), (v) any Scheduled
     Payment or any payment which is not in fact paid within five days of the
     Regular Distribution Date applicable thereto or (vi) any proceeds from the
     sale of any such Equipment Note by the Trustee pursuant to Article VI
     hereof; and Special Payments means all of such Special Payments.
                 ----------------                                    

 
                                      10

          Special Payments Account:  With respect to the Certificates of any
          ------------------------                                          
     series, means the account or accounts created and maintained for such
     series pursuant to Section 4.01(b) and the related Trust Supplement.

          Specified Investments:  With respect to any Trust, means, unless
          ---------------------                                           
     otherwise specified in the related Trust Supplement, (i) obligations of, or
     guaranteed by, the United States Government or agencies thereof, (ii) open
     market commercial paper of any corporation incorporated under the laws of
     the United States of America or any State thereof rated at least P-2 or its
     equivalent by Moody's Investors Service, Inc. or at least A-2 or its
     equivalent by Standard & Poor's Corporation, (iii) certificates of deposit
     issued by commercial banks organized under the laws of the United States or
     of any political subdivision thereof having a combined capital and surplus
     in excess of $500,000,000 which banks or their holding companies have a
     rating of A or its equivalent by Moody's Investors Service, Inc. or
     Standard & Poor's Corporation; provided, however, that the aggregate amount
                                    --------  -------                           
     at an one time so invested in certificates of deposit issued by any one
     bank shall not exceed 5% of such bank's capital and surplus, (iv) U.S.
     dollar denominated offshore certificates of deposit issued by, or offshore
     time deposits with, any commercial bank described in (iii) or any
     subsidiary thereof and (v) repurchase agreements with any financial
     institution having combined capital and surplus of at least $500,000,000
     with any of the obligations described in clauses (i) through (iv) as
     collateral; provided further that if all of the above investments are
                 -------- -------                                         
     unavailable, the entire amounts to be invested may be used to purchase
     Federal Funds from an entity described in clause (iii) above; and
     provided further that no investment shall be eligible as a "Specified
     -------- -------                                                     
     Investment" unless the final maturity or date of return of such investment
     is on or before the Special Distribution Date next following the Cut-off
     Date for such Trust by more than 20 days.

          Substitute Aircraft:  With respect to any Trust, means any Aircraft of
          -------------------                                                   
     the type specified in this Agreement and, at the election of the Company,
     substituted prior to the applicable Cut-off Date, pursuant to the terms of
     this Agreement.

          Transfer Date:  Has the meaning assigned to that term or any of the
          -------------                                                      
     terms "Delivery Date", "Funding Date" or "Closing Date" in a Note Purchase
     Agreement.

          Trust:  With respect to the Certificates of any series, means the
          -----                                                            
     trust under this Agreement.

          Trustee:  Means the institution executing this Basic Agreement as
          -------                                                          
     Trustee, or its successor in interest, and any successor or other trustee
     appointed as provided herein; provided that if the same institution is not
                                   --------                                    
     acting as the Trustee in respect of all series of Certificates, the phrase
     "the Trustee" shall, unless the context otherwise

 
                                      11

     requires, mean, as to any series of Certificates, the institution acting as
     the Trustee in respect of such series.

          Trust Indenture Act:  Except as otherwise provided in Section 9.06,
          -------------------                                                
     means the Trust Indenture Act of 1939 as in force at the date as of which
     this Basic Agreement was executed.

          Trust Property:  With respect to any Trust, means the Equipment Notes
          --------------                                                       
     held as the property of such Trust and all monies at any time paid thereon
     and all monies due and to become due thereunder, funds from time to time
     deposited in the related Escrow Account, the related Certificate Account
     and the related Special Payments Account and any proceeds from the sale by
     the Trustee pursuant to Article VI hereof of any such Equipment Note.

          Trust Supplement:  Means an agreement supplemental hereto pursuant to
          ----------------                                                     
     which (i) a separate Trust is created for the benefit of the Holders of the
     Certificates of a series, (ii) the issuance of the Certificates of such
     series representing fractional undivided interests in such Trust is
     authorized and (iii) the terms of the Certificates of such series are
     established.

          Section 1.02.  Compliance Certificates and Opinions.  Upon any
                         ------------------------------------           
application or request by the Company, any Owner Trustee or any Loan Trustee to
the Trustee to take any action under any provision of this Basic Agreement or,
in respect of the Certificates of any series, this Agreement, the Company, such
Owner Trustee or such Loan Trustee, as the case may be, shall furnish to the
Trustee an Officers' Certificate stating that, in the opinion of the signers,
all conditions precedent, if any, provided for in this Basic Agreement or this
Agreement relating to the proposed action have been complied with and an opinion
of Counsel stating that in the opinion of such counsel all such conditions
precedent, if any, have been complied with, except that in the case of any such
application or request as to which the furnishing of such documents is
specifically required by any provision of this Basic Agreement or this Agreement
relating to such particular application or request, no additional certificate or
opinion need be furnished.

          Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Basic Agreement or, in respect of the
Certificates of any series, this Agreement (other than a certificate provided
pursuant to Section 8.04(d)) or any Trust Supplement shall include:

          (1) a statement that each individual signing such certificate or
     opinion has read such covenant or condition and the definitions in this
     Basic Agreement or this Agreement relating thereto;

 
                                      12


          (2)  a brief statement as to the nature and scope of the examination
     or investigation upon which the statements or opinions contained in such
     certificate or opinion are based;

          (3) a statement that, in the opinion of each such individual, he has
     made such examination or investigation as is necessary to enable him to
     express an informed opinion as to whether or not such covenant or condition
     has been complied with; and

          (4) a statement as to whether, in the opinion of each such individual,
     such condition or covenant has been complied with.

          Section 1.03. Form of Documents Delivered to Trustee.  In any case
                        --------------------------------------              
where several matters are required to be certified by, or covered by an opinion
of, any specified Person, it is not necessary that all such matters be certified
by, or covered by the opinion of, only one such Person, or that they be so
certified or covered by only one document, but one such Person may certify or
give an opinion with respect to some matters and one or more other such Persons
as to other matters and any such Person may certify or give an opinion as to
such matters in one or several documents.

          Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Basic Agreement or, in respect of the Certificates of any
series, this Agreement, they may, but need not, be consolidated and form one
instrument.

          Section 1.04.  Acts of Certificateholders.  (a)  Any direction,
                         --------------------------                      
consent, waiver or other action provided by this Agreement in respect of the
Certificates of any series to be given or taken by Certificateholders may be
embodied in and evidenced by one or more instruments of substantially similar
tenor signed by such Certificateholders in person or by an agent or proxy duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Trustee and, where it is hereby expressly required pursuant to this
Agreement, to the Company or any Loan Trustee.  Such instrument or instruments
(and the action embodied therein and evidenced thereby) are herein sometimes
referred to as the "Act" of the Certificateholders signing such instrument or
instruments.  Proof of execution of any such instrument or of a writing
appointing any such agent shall be sufficient for any purpose of such Trust
Supplement and conclusive in favor of the Trustee, the Company and the related
Loan Trustee, if made in the manner provided in this Section.

          (b) The fact and date of the execution by any Person of any such
instrument or writing may be proved by the certificate of any notary public or
other officer of any jurisdiction authorized to take acknowledgments of deeds or
administer oaths that the

 
                                      13


Person executing such instrument acknowledged to him the execution thereof, or
by an affidavit of a witness to such execution sworn to before any such notary
or such other officer and where such execution is by an officer of a corporation
or association or a member of a partnership, on behalf of such corporation,
association or partnership, such certificate or affidavit shall also constitute
sufficient proof of his authority.  The fact and date of the execution of any
such instrument or writing, or the authority of the Person executing the same,
may also be proved in any other reasonable manner which the Trustee deems
sufficient.

          (c) In determining whether the Certificateholders of the requisite
Fractional Undivided Interests of Certificates of any series Outstanding have
given any direction, consent or waiver (a "Direction"), under this Agreement,
Certificates owned by the Company, any related Owner Trustee, any related Owner
Participant or any Affiliate of any such Person shall be disregarded and deemed
not to be Outstanding for purposes of any such determination.  In determining
whether the Trustee shall be protected in relying upon any such Direction, only
Certificates which the Trustee knows to be so owned shall be so disregarded.
Notwithstanding the foregoing, (i) if any such Person owns 100% of the
Certificates of any series Outstanding, such Certificates shall not be so
disregarded as aforesaid, and (ii) if any amount of Certificates of such series
so owned by any such Person have been pledged in good faith, such Certificates
shall not be disregarded as aforesaid if the pledgee establishes to the
satisfaction of the Trustee the pledgee's right so to act with respect to such
Certificates and that the pledgee is not the Company, any related Owner Trustee,
any related Owner Participant or any Affiliate of any such Person.

          (d) The Company may at its option by delivery of an Officers'
Certificate to the Trustee set a record date to determine the Certificateholders
in respect of the Certificates of any series entitled to give any consent
request, demand, authorization, direction, notice, waiver or other Act.
Notwithstanding Section 316(c) of the Trust Indenture Act, such record date
shall be the record date specified in such Officers' Certificate which shall be
a date not more than 30 days prior to the first solicitation of
Certificateholders in connection therewith.  If such a record date is fixed,
such consent, request, demand, authorization, direction, notice, waiver or other
Act may be given before or after such record date, but only the
Certificateholders of record of the applicable series at the close of business
on such record date shall be deemed to be Certificateholders for the purposes of
determining whether Certificateholders of the requisite proportion of
Outstanding Certificates of such series have authorized or agreed or consented
to such consent, request, demand, authorization, direction, notice, waiver or
other Act, and for that purpose the Outstanding Certificates of such series
shall be computed as of such record date; provided that no such consent,
                                          --------                      
request, demand, authorization, direction, notice, waiver or other act by the
Certificateholders on such record date shall be deemed effective unless it shall
become effective pursuant to the provisions of this Basic Agreement not later
than one year after the record date.

 
                                      14

          (e) Any direction, consent, waiver or other action by the Holder of
any Certificate shall bind the Holder of every Certificate issued upon the
transfer thereof or in exchange therefor or in lieu thereof, whether or not
notation of such action is made upon such Certificate.

          (f) Except as otherwise provided in Section 1.04(c), Certificates of
any series owned by or pledged to any Person shall have an equal and
proportionate benefit under the provisions of this Agreement, without
preference, priority, or distinction as among all of the Certificates of such
series.


                                  ARTICLE II

                      ORIGINAL ISSUANCE OF CERTIFICATES;
                        ACQUISITION OF EQUIPMENT NOTES

          Section 2.01.  Amount Unlimited; Issuable in Series. (a) The aggregate
                         ------------------------------------                   
principal amount of Certificates which may be authenticated and delivered under
this Basic Agreement is unlimited.  The Certificates may be issued from time to
time in one or more series and shall be designated generally as the "Pass
Through Certificates", with such further designations added or incorporated in
such title for the Certificates of each series as specified in the related Trust
Supplement.  Each Certificate shall bear upon its face the designation so
selected for the series to which it belongs.  All Certificates of the same
series shall be substantially identical except that the Certificates of a series
may differ as to denomination and as may otherwise be provided in the Trust
Supplement establishing the Certificates of such series.  Each series of
Certificates issued pursuant to this Agreement will evidence fractional
undivided interests in the related Trust and will have no rights, benefits or
interests in respect of any other Trust or the Trust Property held therein.  All
Certificates of the same series shall be in all respects equally and ratably
entitled to the benefits of this Agreement without preference, priority or
distinction on account of the actual time or times of authentication and
delivery, all in accordance with the terms and provisions of this Agreement.

          (b) The following matters shall be established with respect to the
Certificates of each series issued hereunder by a Trust Supplement executed and
delivered by and between the Company and the Trustee:

          (1) the formation of the Trust as to which the Certificates of such
     series represent fractional undivided interests and its designation (which
     designation shall distinguish such Trust from each other Trust created
     under this Basic Agreement and a Trust Supplement);

 
                                      15


          (2) the specific title of the Certificates of such series (which title
     shall distinguish the Certificates of such series from each other series of
     Certificates created under this Basic Agreement and a Trust Supplement);

          (3) any limit upon the aggregate principal amount of the Certificates
     of such series which may be authenticated and delivered (which limit shall
     not pertain to Certificates authenticated and delivered upon registration
     of transfer of, or in exchange for, or in lieu of, other Certificates of
     the series pursuant to Sections 3.03, 3.04 and 3.05);

          (4) the Cut-off Date with respect to the Certificates of such series;

          (5) the Regular Distribution Dates applicable to the Certificates of
     such series;

          (6) the Special Distribution Dates applicable to the Certificates of
     such series and the related Trust;

          (7) if other than as provided in Section 7.11(b), the Registrar or the
     Paying Agent for the Certificates of such series, including any Co-
     Registrar or additional Paying Agent;

          (8) if other than as provided in Section 3.01, the denominations in
     which the Certificates of such series shall be issuable;

          (9) the specific form of the Certificates of such series (including
     the interest rate applicable thereto) and whether or not Certificates of
     such series are to be issued as Book-Entry Certificates and, if such
     Certificates are to be Book-Entry Certificates, the Form of Letter of
     Representations, if any;

          (10) a description of the Equipment Notes to be acquired and held in
     the related Trust and of the related Aircraft and Note Documents;

          (11) provisions with respect to the terms for which the definitions
     set forth in Article I hereof or the terms of Section 11.01 hereof permit
     or require further specification in the related Trust Supplement;

          (12)  any restrictions (including legends) in respect of ERISA;  and

 
                                      16

          (13)  any other terms of the Certificates of such series  (which of
     such terms shall not be inconsistent with the provisions of the Trust
     Indenture Act), including any terms which may be required or advisable
     under United States laws or regulations or advisable in connection with the
     marketing of Certificates of the series.

          (c) At any time and from time to time after the execution and delivery
of this Basic Agreement and a Trust Supplement forming a Trust and establishing
the terms of Certificates of a series, Certificates of such series shall be
executed, authenticated and delivered by the Trustee to the Person or Persons
specified by the Company upon request of the Company and upon satisfaction of
any conditions precedent set forth in such Trust Supplement or in any other
document to which a Trustee is a party relating to the issuance of the
Certificates of such series.

          Section 2.02  Acquisition of Equipment Notes.  (a)  Unless otherwise
                        ------------------------------                        
specified in the related Trust Supplement, on or prior to the Issuance Date of
the Certificates of a series, the Trustee shall execute and deliver the related
Note Purchase Agreements in the form delivered to the Trustee by the Company.
The Trustee shall issue and sell such Certificates, in authorized denominations
and in such Fractional Undivided Interests, so as to result in the receipt of
consideration in an amount equal to the aggregate principal amount of such
Equipment Notes and, concurrently therewith, the Trustee shall purchase,
pursuant to the terms and conditions of the Note Purchase Agreements, the
Equipment Notes at a purchase price equal to the amount of such consideration so
received.  Except as provided in Sections 3.03, 3.04 and 3.05 hereof, the
Trustee shall not execute, authenticate or deliver Certificates of such series
in excess of the aggregate amount specified in this paragraph.  The provisions
of this Subsection (a) are subject to the provisions of Subsection (b) below.

          (b) If on or prior to the Issuance Date with respect to a series of
Certificates the Company shall deliver to the Trustee a Postponement Notice
relating to one or more Postponed Notes, the Trustee shall postpone the purchase
of such Postponed Notes and shall deposit into an escrow account (as to such
Trust, the "Escrow Account") to be maintained as a part of the related Trust an
amount equal to the purchase price of such Postponed Notes (the "Escrowed
Funds").  The Escrowed Funds so deposited shall be invested by the Trustee at
the direction and risk of, and for the benefit of, the Company in Specified
Investments (i) maturing no later than any scheduled Transfer Date relating to
such series of Certificates or (ii) if no such Transfer Date has been scheduled,
maturing on the next Business Day, or (iii) if the Company has given notice to
the Trustee that any Postponed Notes will not be issued, with respect to the
portion of the Escrowed Funds relating to such Postponed Notes, maturing on the
next applicable Special Distribution Date, if such investments are reasonably
available for purchase.  The Trustee shall make withdrawals from the Escrow
Account only as provided in this Agreement.  Upon request of the Company on one
or more occasions and the satisfaction of the closing conditions specified in
the applicable Note Purchase Agreements on or prior to the related Cut-off Date,
the Trustee

 
                                      17


shall purchase the applicable Postponed Notes with the Escrowed Funds withdrawn
from the Escrow Account.  The purchase price shall equal the principal amount of
such Postponed Notes.

          The Trustee shall hold all Specified Investments until the maturity
thereof and will not sell or otherwise transfer Specified Investments.  If
Specified Investments held in an Escrow Account mature prior to any applicable
Transfer Date, any proceeds received on the maturity of such Specified
Investments (other than any earnings thereon) shall be reinvested by the Trustee
at the direction and risk of, and for the benefit of, the Company in Specified
Investments maturing as provided in the preceding paragraph.

          Any earnings on Specified Investments received from time to time by
the Trustee shall be promptly distributed to the Company.  The Company shall pay
to the Trustee for deposit to the relevant Escrow Account an amount equal to any
losses on such Specified Investments as incurred.  On the Initial Regular
Distribution Date in respect of the Certificates of any series, the Company will
pay (in immediately available funds) to the Trustee an amount equal to the
interest that would have accrued on any Postponed Notes, if any, purchased after
the Issuance Date if such Postponed Notes had been purchased on the Issuance
Date, from the Issuance Date to, but not including, the date of the purchase of
such Postponed Notes by the Trustee.

          If, in respect of the Certificates of any series, the Company notifies
the Trustee prior to the Cut-off Date that any Postponed Notes will not be
issued on or prior to the Cut-off Date for any reason, on the next Special
Distribution Date for such Certificates occurring more than 20 days following
the date of such notice (i) the Company shall pay to the Trustee for deposit in
the related Special Payments Account, in immediately available funds, an amount
equal to the interest that would have accrued on the Postponed Notes designated
in such notice at a rate equal to the interest rate applicable to such
Certificates from the Issuance Date to, but not including, such Special
Distribution Date and (ii) the Trustee shall transfer an amount equal to that
amount of Escrowed Funds that would have been used to purchase the Postponed
Notes designated in such notice and the amount paid by the Company pursuant to
the immediately preceding clause (i) to the related Special Payments Account for
distribution as a Special Payment in accordance with the provisions hereof.

          If, on such Cut-off Date, an amount equal to less than all of the
Escrowed Funds (other than Escrowed Funds referred to in the immediately
preceding paragraph) has been used to purchase Postponed Notes, on the next
Special Distribution Date occurring more than 20 days following such Cut-off
Date (i) the Company shall pay to the Trustee for deposit in such Special
Payments Account, in immediately available funds, an amount equal to the
interest that would have accrued on such Postponed Notes contemplated to be
purchased with such unused Escrowed Funds (other than Escrowed Funds referred to
in the

 
                                      18

immediately preceding paragraph) but not so purchased at a rate equal to the
interest rate applicable to such Certificates from the Issuance Date to, but not
including, such Special Distribution Date and (ii) the Trustee shall transfer
such unused Escrowed Funds and the amount paid by the Company pursuant to the
immediately preceding clause (i) to such Special Payments Account for
distribution as a Special Payment in accordance with the provisions hereof.

          Section 2.03.  Acceptance by Trustee.  The Trustee, upon the execution
                         ---------------------                                  
and delivery of a Trust Supplement creating a Trust and establishing a series of
Certificates, shall acknowledge its acceptance of all right, title and interest
in and to the Equipment Notes to be acquired pursuant to Section 2.02 hereof and
the Note Purchase Agreements and shall declare that the Trustee holds and will
hold such right, title and interest, together with all other property
constituting the Trust Property of such Trust, for the benefit of all then
present and future Certificateholders of such series, upon the trusts herein and
in such Trust Supplement set forth.  By its payment for and acceptance of each
Certificate of such series issued to it under this Agreement, each initial
Certificateholder of such series as grantor of such Trust shall thereby join in
the creation and declaration of such Trust.

          Section 2.04.  Limitation of Powers.  Each Trust shall be constituted
                         --------------------                                  
solely for the purpose of making the investment in the Equipment Notes provided
for in the related Trust Supplement, and, except as set forth herein or in this
Agreement, the Trustee shall not be authorized or empowered to acquire any other
investments or engage in any other activities and, in particular, the Trustee
shall not be authorized or empowered to do anything that would cause such Trust
to fail to qualify as a "grantor trust" for federal income tax purposes
(including as subject to this restriction, acquiring the Aircraft (as defined in
the respective related Indentures) by bidding such Equipment Notes or otherwise,
or taking any action with respect to any such Aircraft once acquired).


                                  ARTICLE III

                               THE CERTIFICATES

          Section 3.01.  Form, Denomination and Execution of Certificates.  The
                         ------------------------------------------------      
Certificates shall be issued in registered form without coupons and shall be
substantially in the form attached hereto as Exhibit A, with such omissions,
variations and insertions as are permitted by this Agreement, and may have such
letters, numbers or other marks of identification and such legends or
endorsements printed, lithographed or engraved thereon, as may be required to
comply with the rules of any securities exchange on which such Certificates may
be listed or to conform to any usage in respect thereof, or as may, consistently
herewith, be prescribed by the Trustee or by the officer executing such

 
                                      19

Certificates, such determination by said officer to be evidenced by his signing
the Certificates.

          Except as provided in Section 3.09, the definitive Certificates of
such series shall be printed, lithographed or engraved or produced by any
combination of these methods or may be produced in any other manner permitted by
the rules of any securities exchange on which the Certificates may be listed,
all as determined by the officer executing such Certificates, as evidenced by
his execution of such Certificates.

          Except as otherwise provided in the related Trust Supplement, the
Certificates of each series shall be issued in minimum denominations of $1,000
or integral multiples thereof except that one Certificate of such series may be
issued in a denomination of less than $1,000.

          The Certificates of such series shall be executed on behalf of the
Trustee by manual or facsimile signature of a Responsible Officer of the
Trustee.  Certificates of any series bearing the manual or facsimile signature
of an individual who was, at the time when such signature was affixed,
authorized to sign on behalf of the Trustee shall be valid and binding
obligations of the Trustee, notwithstanding that such individual has ceased to
be so authorized prior to the authentication and delivery of such Certificates
or did not hold such office at the date of such Certificates.  No Certificate of
any series shall be entitled to any benefit under this Agreement, or be valid
for any purpose unless there appears on such Certificate a certificate of
authentication substantially in the form set forth in Exhibit B hereto executed
by the Trustee by manual signature, and such certificate of authentication upon
any Certificate shall be conclusive evidence, and the only evidence, that such
Certificate has been duly authenticated and delivered hereunder.  All
Certificates of any series shall be dated on the date of their authentication.

          Section 3.02.  Authentication of Certificates.  The Trustee shall duly
                         ------------------------------                         
authenticate and deliver Certificates of each series in authorized denominations
equalling in the aggregate the aggregate principal amount of the Equipment Notes
to be purchased by the Trustee pursuant to the related Note Purchase Agreements
and evidencing the entire ownership of the related Trust.

          Section 3.03.  Temporary Certificates.  Pending the preparation of
                         ----------------------                             
definitive Certificates of any series, the Trustee may execute, authenticate and
deliver temporary Certificates of such series which are printed, lithographed,
typewritten, or otherwise produced, in any denomination, containing
substantially the same terms and provisions as set forth in Exhibit A hereto,
except for such appropriate insertions, omissions, substitutions and other
variations relating to their temporary nature as the officer executing such
temporary Certificates may determine, as evidenced by its execution of such
temporary Certificates.

 
                                      20


          If temporary Certificates of any series are issued, the Company will
cause definitive Certificates of such series to be prepared without unreasonable
delay.  After the preparation of definitive Certificates of such series, the
temporary Certificates shall be exchangeable for definitive Certificates upon
surrender of such temporary Certificates at the Corporate Trust Office of the
Trustee, or at the office or agency of the Trustee maintained in accordance with
Section 7.11, without charge to the holder.  Upon surrender for cancellation of
any one or more temporary Certificates, the Trustee shall execute, authenticate
and deliver in exchange therefor definitive Certificates of like series, in
authorized denominations and of a like aggregate Fractional Undivided Interest.
Until so exchanged, such temporary Certificates shall in all respects be
entitled to the same benefits under this Agreement as definitive Certificates.

          Section 3.04.  Registration of Transfer and Exchange of Certificates.
                         -----------------------------------------------------  
The Trustee shall cause to be kept at the office or agency to be maintained by
it in accordance with the provisions of Section 7.11 a register (the "Register")
for each series of Certificates in which, subject to such reasonable regulations
as it may prescribe, the Trustee shall provide for the registration of
Certificates of such series and of transfers and exchanges of such Certificates
as herein provided.  The Trustee shall initially be the registrar (the "
Registrar") for the purpose of registering Certificates of each series and
transfers and exchanges of such Certificates as herein provided.

          Upon surrender for registration of transfer of any Certificate at the
Corporate Trust Office or such other office or agency, the Trustee shall
execute, authenticate and deliver, in the name of the designated transferee or
transferees, one or more new Certificates of like series, in authorized
denominations of a like aggregate Fractional Undivided Interest.

          At the option of a Certificateholder, Certificates may be exchanged
for other Certificates of like series, in authorized denominations and of a like
aggregate Fractional Undivided Interest, upon surrender of the Certificates to
be exchanged at any such office or agency.  Whenever any Certificates are so
surrendered for exchange, the Trustee shall execute, authenticate and deliver
the Certificates that the Certificateholder making the exchange is entitled to
receive.  Every Certificate presented or surrendered for registration of
transfer or exchange shall be duly endorsed or accompanied by a written
instrument of transfer in form satisfactory to the Trustee and the Registrar
duly executed by the Certificateholder thereof or its attorney duly authorized
in writing.

          No service charge shall be made to a Certificateholder for any
registration of transfer or exchange of Certificates, but the Trustee shall
require payment of a sum sufficient to cover any tax or governmental charge that
may be imposed in connection with any transfer or exchange of Certificates.

 
                                      21


          All Certificates surrendered for registration of transfer and exchange
shall be cancelled and subsequently destroyed by the Trustee.

          Section 3.05.  Mutilated, Destroyed, Lost or Stolen Certificates.  If
                         -------------------------------------------------     
(a) any mutilated Certificate is surrendered to the Registrar or the Registrar
receives evidence to its satisfaction of the destruction, loss or theft of any
Certificate and (b) there is delivered to the Registrar and the Trustee such
security, indemnity or bond, as may be required by them to save each of them
harmless, then, in the absence of notice to the Registrar or the Trustee that
such destroyed, lost or stolen Certificate has been acquired by a bona fide
purchaser, the Trustee shall execute, authenticate and deliver, in exchange for
or in lieu of any such mutilated, destroyed, lost or stolen Certificate, a new
Certificate or Certificates of like series, in authorized denominations and of
like Fractional Undivided Interest.  In connection with the issuance of any new
Certificate under this Section 3.05, the Trustee shall require the payment of a
sum sufficient to cover any tax or other governmental charge that may be imposed
in relation thereto and any other expenses (including the fees and expenses of
the Trustee and the Registrar) connected therewith.  Any duplicate Certificate
issued pursuant to this Section 3.05 shall constitute conclusive evidence of the
appropriate Fractional Undivided Interest in the related Trust, as if originally
issued, whether or not the lost, stolen or destroyed Certificate shall be found
at any time.

          Section 3.06.  Persons Deemed Owners.  Prior to due presentation of a
                         ---------------------                                 
Certificate for registration of transfer, the Trustee, the Registrar and any
Paying Agent of the Trustee may treat the person in whose name any Certificate
is registered as the owner of such Certificate for the purpose of receiving
distributions pursuant to Section 4.02 and for all other purposes whatsoever,
and none of the Trustee, the Registrar or any Paying Agent of the Trustee shall
be affected by any notice to the contrary.

          Section 3.07.  Cancellation.  All Certificates surrendered for payment
                         ------------                                           
or transfer or exchange, if surrendered to any Person party hereto other than
the Registrar, shall be delivered to the Registrar for cancellation.  No
Certificates shall be authenticated in lieu of or in exchange for any
Certificates cancelled as provided in this Section, except as expressly
permitted by this Agreement.  All cancelled Certificates held by the Registrar
shall be destroyed and a certification of their destruction delivered to the
Trustee.

          Section 3.08.  Limitation of Liability for Payments.  All payments
                         ------------------------------------               
distributions made to Certificateholders of any series under the related Trust
Supplement shall be made only from the Trust Property of the related Trust and
only to the extent that the Trustee shall have sufficient income or proceeds
from such Trust Property to make such payments in accordance with the terms of
Article IV of this Agreement.  Each Certificateholder, by its acceptance of a
Certificate, agrees that it will look solely to the income and proceeds from the
Trust Property of the related Trust to the extent available for distribution to
such Certificateholder as provided in this Agreement.

 
                                      22


          Section 3.09.  Book-Entry and Definitive Certificates.  (a)  Except
                         --------------------------------------              
for one Certificate of each series that may be issued in a denomination of less
than $1,000, the Certificates of any series may be issued in the form of one or
more typewritten Certificates representing the Book-Entry Certificates of such
series, to be delivered to The Depository Trust Company, as the initial Clearing
Agency, by, or on behalf of, the Company.  In such case, the Certificates of
such series delivered to The Depository Trust Company shall initially be
registered on the Register in the name of CEDE & Co., the nominee of the initial
Clearing Agency, and no Certificate Owner will receive a definitive certificate
representing such Certificate Owner's interest in the Certificates of such
series, except as provided above and in Subsection (d) below.  As to the
Certificates of any series, except with respect to the one Certificate of such
series that may be issued in a denomination of less than $1,000, unless and
until definitive, fully registered Certificates (the "Definitive Certificates")
have been issued pursuant to Subsection (d) below:

          (i) the provisions of this Section 3.09 shall be in full force and
     effect;

          (ii) the Company, the Paying Agent, the Registrar and the Trustee may
     deal with the Clearing Agency for all purposes (including the making of
     distributions on the Certificates) as the authorized representative of the
     Certificate Owners;

          (iii)   to the extent that the provisions of this Section 3.09
     conflict with any other provisions of this Agreement (other than the
     provisions of any Trust Supplement amending this Section 3.09 as permitted
     by this Basic Agreement), the provisions of this Section 3.09 shall
     control;

          (iv) the rights of Certificate Owners shall be exercised only through
     the Clearing Agency and shall be limited to those established by law and
     agreements between such Certificate Owners and the Clearing Agency
     Participants; and until Definitive Certificates are issued pursuant to
     Subsection (d) below, the Clearing Agency will make book-entry transfers
     among the Clearing Agency Participants and receive and transmit
     distributions of principal and interest and premium, if any, on the
     Certificates to such Clearing Agency Participants; and

          (v) whenever this Agreement requires or permits actions to be taken
     based upon instructions or directions of Certificateholders of such series
     holding Certificates of such series evidencing a specified percentage of
     the Fractional Undivided Interests in the related Trust, the Clearing
     Agency shall be deemed to represent such percentage only to the extent that
     it has received instructions to such effect from Certificate Owners and/or
     Clearing Agency Participants owning or representing, respectively, such
     required percentage of the beneficial interest in Certificates of such
     series and has delivered such instructions to the Trustee.  The Trustee
     shall have no

 
                                      23


     obligation to determine whether the Clearing Agency has in fact received
     any such instructions.

          (b) Except with respect to the one Certificate of each series that may
be issued in a denomination of less than $1,000, whenever notice or other
communication to the Certificateholders of such series is required under this
Agreement, unless and until Definitive Certificates shall have been issued
pursuant to Subsection (d) below, the Trustee shall give all such notices and
communications specified herein to be given to Certificateholders of such series
to the Clearing Agency and/or the Clearing Agency Participants, and shall make
available additional copies as requested by such Clearing Agency Participants.

          (c) Unless and until Definitive Certificates of a series are issued
pursuant to Subsection (d) below, on the Record Date prior to each applicable
Regular Distribution Date and Special Distribution Date, the Trustee will
request from the Clearing Agency a Securities Position Listing setting forth the
names of all Clearing Agency Participants reflected on the Clearing Agency's
books as holding interests in the Certificates on such Record Date.  The Trustee
shall mail to each such Clearing Agency Participant the statements described in
Section 4.03 hereof.

          (d) If with respect to the Certificates of any series (i) the Company
advises the Trustee in writing that the Clearing Agency is no longer willing or
able to properly discharge its responsibilities and the Trustee or the Company
is unable to locate a qualified successor, (ii) the Company at its option,
advises the Trustee in writing that it elects to terminate the book-entry system
through the Clearing Agency or (iii) after the occurrence of an Event of
Default, Certificate Owners of Book-Entry Certificates of such series evidencing
Fractional Undivided Interests aggregating not less than a majority in interest
in the related Trust, by Act of said Certificate Owners delivered to the Company
and the Trustee, advise the Company, the Trustee and the Clearing Agency through
the Clearing Agency Participants in writing that the continuation of a book-
entry system through the Clearing Agency is no longer in the best interests of
the Certificate Owners of such series, then the Trustee shall notify all
Certificate Owners of such series, through the Clearing Agency, of the
occurrence of any such event and of the availability of Definitive Certificates.
Upon surrender to the Trustee of all the Certificates of such series held by the
Clearing Agency, accompanied by registration instructions from the Clearing
Agency for registration of Definitive Certificates in the names of Certificate
Owners of such series, the Trustee shall issue and deliver the Definitive
Certificates of such series in accordance with the instructions of the Clearing
Agency.  None of the Company, the Registrar, the Paying Agent or the Trustee
shall be liable for any delay in delivery of such instructions and may
conclusively rely on, and shall be protected in relying on, such registration
instructions.  Upon the issuance of Definitive Certificates of such series, the
Trustee shall recognize the Person in whose name the

 
                                      24


Definitive Certificates are registered in the Register as Certificateholders
hereunder.  Neither the Company nor the Trustee shall be liable if the Trustee
or the Company is unable to locate a qualified successor Clearing Agency.

          (e)  Except as otherwise provided in the related Trust Supplement, the
Trustee shall enter into the applicable Letter of Representations with respect
to such series of Certificates and fulfill its responsibilities thereunder.

          (f) The provisions of this Section 3.09 may be made inapplicable to
any series or may be amended with respect to any series in the related Trust
Supplement.


                                  ARTICLE IV

                         DISTRIBUTIONS; STATEMENTS TO
                              CERTIFICATEHOLDERS

          Section 4.01.  Certificate Account and Special Payments Account.  (a)
                         ------------------------------------------------       
The Trustee shall establish and maintain on behalf of the Certificateholders of
each series a Certificate Account as one or more non-interest-bearing accounts.
The Trustee shall hold the Certificate Account in trust for the benefit of the
Certificateholders of such series, and shall make or permit withdrawals
therefrom only as provided in this Agreement.  On each day when a Scheduled
Payment is made under the Indenture to the Trustee, as holder of the Equipment
Notes issued under such Indenture, the Trustee upon receipt shall immediately
deposit the aggregate amount of such Scheduled Payment in the applicable
Certificate Account.

          (b) The Trustee shall establish and maintain on behalf of the
Certificateholders of each series a Special Payments Account as one or more
accounts, which shall be non-interest bearing except as provided in Section
4.04. The Trustee shall hold the Special Payments Account in trust for the
benefit of the Certificateholders of such series and shall make or permit
withdrawals therefrom only as provided in this Agreement.  On each day when one
or more Special Payments (other than a Special Payment that represents the
proceeds of any sale pursuant to Article VI hereof by the Trustee of an
Equipment Note) are made under the Indenture to the Trustee, as holder of the
Equipment Notes issued under such Indenture or pursuant to the last two
paragraphs of Section 2.02(b), the Trustee upon receipt shall immediately
deposit the aggregate amounts of such Special Payments in such Special Payments
Account.  Upon the sale of the Equipment Notes by the Trustee pursuant to
Article VI hereof and the realization of any proceeds thereof, the Trustee shall
deposit the aggregate amount of such proceeds as a Special Payment in the
applicable Special Payments Account.

 
                                      25


          (c) The Trustee shall present to the Loan Trustee to which an
Equipment Note relates such Equipment Note on the date of its stated final
maturity or, in the case of any Equipment Note which is to be redeemed in whole
pursuant to the relevant Indenture, on the applicable redemption date under such
Indenture.

          Section 4.02.  Distributions from Certificate Account and Special
                         --------------------------------------------------
Payments Account.  (a)  On each Regular Distribution Date with respect to a
- ----------------                                                           
series of Certificates or as soon thereafter as the Trustee has confirmed
receipt of the payment of the Scheduled Payments due on the Equipment Notes held
in the related Trust on such date, the Trustee shall distribute out of the
applicable Certificate Account the entire amount deposited therein pursuant to
Section 4.01(a).  There shall be so distributed to each Certificateholder of
record of such series on the Record Date with respect to such Regular
Distribution Date (other than as provided in Section 11.01 concerning the final
distribution) by check mailed to such Certificateholder, at the address
appearing in the Register, such Certificateholder's pro rata share (based on the
aggregate Fractional Undivided Interest in the related Trust held by such
Certificateholder) of the aggregate amount in the applicable Certificate Amount.

          (b) On each Special Distribution Date with respect to any Special
Payment with respect to a series of Certificates or as soon thereafter as the
Trustee has confirmed receipt of the Special Payments due on the Equipment Notes
held in the related Trust or realized upon the sale of such Equipment Note, the
Trustee shall distribute out of the applicable Special Payments Account the
entire amount deposited therein pursuant to Section 4.01(b) of such Special
Payment.  There shall be so distributed to each Certificateholder of record of
such series on the Record Date with respect to such Special Distribution Date
(other than as provided in Section 11.01 concerning the final distribution) by
check mailed to such Certificateholder, at the address appearing in the
Register, such Certificateholder's pro rata share (based on the aggregate
Fractional Undivided Interest in the related Trust held by such
Certificateholder) of the aggregate amount in the applicable Special Payments
Account on account of such Special Payment.

          (c) The Trustee shall, at the expense of the Company, cause notice of
each Special Payment with respect to a series of Certificates to be mailed to
each Certificateholder of such series at his address as it appears in the
Register.  In the event of redemption or purchase of Equipment Notes held in the
related Trust, such notice shall be mailed not less than 20 days prior to the
date any such Special Payment is scheduled to be distributed.  In the case of
any other Special Payments, such notice shall be mailed as soon as practicable
after the Trustee has confirmed that it has received funds for such Special
Payment.  Notices mailed by the Trustee shall set forth:

          (i) the Special Distribution Date and the Record Date therefor (except
     as otherwise provided in Section 11.01),

 
                                      26

          (ii) the amount of the Special Payment for each $1,000 face amount
     Certificate (taking into account any payment to be made by the Company
     pursuant to Section 2.02(b)) and the amount thereof constituting principal,
     premium, if any, and interest,

          (iii)  the reason for the Special Payment, and

          (iv) if the Special Distribution Date is the same date as a Regular
     Distribution Date for the Certificates of such series, the total amount to
     be received on such date for each $1,000 face amount Certificate.

If the amount of premium, if any, payable upon the redemption or purchase of an
Equipment Note has not been calculated at the time that the Trustee mails notice
of a Special Payment, it shall be sufficient if the notice sets forth the other
amounts to be distributed and states that any premium received will also be
distributed.

          If any redemption of the Equipment Notes held in any Trust is
cancelled, the Trustee, as soon as possible after learning thereof, shall cause
notice thereof to be mailed to each Certificateholder of the related series at
its address as it appears on the Register.

          Section 4.03.  Statements to Certificateholders. (a)  On each Regular
                         --------------------------------                      
Distribution Date and Special Distribution Date with respect to a series of
Certificates, the Trustee will include with each distribution to
Certificateholders of the related series a statement, giving effect to such
distribution to be made on such Regular Distribution Date or Special
Distribution Date, as the case may be, setting forth the following information
(per a $1,000 face amount Certificate as to (i) and (ii) below):

          (i) The amount of such distribution allocable to principal and the
     amount allocable to premium, if any;

          (ii) The amount of such distribution allocable to interest; and

          (iii)  The Pool Balance and the Pool Factor of the related Trust.

          (b) Within a reasonable period of time after the end of each calendar
year but not later than the latest date permitted by law, the Trustee shall
furnish to each Person who at any time during such calendar year was a
Certificateholder of record a statement containing the sum of the amounts
determined pursuant to clauses (a)(i) and (a)(ii) with respect to the related
Trust for such calendar year or, in the event such Person was a
Certificateholder of record during a portion of such calendar year, for the
applicable portion of such year, and such other items as are readily available
to the Trustee and which a

 
                                      27


Certificateholder shall reasonably request as necessary for the purpose of such
Certificateholder's preparation of its Federal income tax returns.

          Section 4.04.   Investment of Special Payment Moneys.  Any money
                          ------------------------------------            
received by the Trustee pursuant to Section 4.01(b) representing a Special
Payment which is not to be promptly distributed shall, to the extent
practicable, be invested in Permitted Investments by the Trustee pending
distribution of such Special Payment pursuant to Section 4.02.  Any investment
made pursuant to this Section 4.04 shall be in such Permitted Investments having
maturities not later than the date that such moneys are required to be used to
make the payment required under Section 4.02 on the applicable Special
Distribution Date and the Trustee shall hold any such Permitted Investments
until maturity.  The Trustee shall have no liability with respect to any
investment made pursuant to this Section 4.04, other than by reason of the
willful misconduct or negligence of the Trustee.  All income and earnings from
such investments shall be distributed on such Special Distribution Date as part
of such Special Payment.


                                   ARTICLE V

                                  THE COMPANY

          Section 5.01.  Maintenance of Corporate Existence.  The Company, at
                         ----------------------------------                  
its own cost and expense, will do or cause to be done all things necessary to
preserve and keep in full force and effect its corporate existence, rights and
franchises, except as otherwise specifically permitted in Section 5.02;
                                                                       
provided, however, that the Company shall not be required to preserve any right
- --------  -------                                                              
or franchise if the Company shall determine that the preservation thereof is no
longer desirable in the conduct of the business of the Company.

          Section 5.02.  Consolidation, Merger, etc.  The Company shall not
                         ---------------------------                       
consolidate with or merge into any other corporation or convey, transfer or
lease substantially all of its assets as an entirety to any Person unless:

          (a) the corporation formed by such consolidation or into which the
     Company is merged or the Person which acquires by conveyance, transfer or
     lease substantially all of the assets of the Company as an entirety shall
     (i) be a citizen of the United States as defined in Section 40102(a)(15) of
     Title 49 of the United States Code, as amended, and (ii) hold an air
     carrier operating certificate issued by the Secretary of Transportation
     pursuant to Chapter 447 of Title 49 of the United States Code, as amended,
     for aircraft capable of carrying 10 or more individuals or 6,000 pounds or
     more of cargo;

 
                                      28


          (b) the corporation formed by such consolidation or into which the
     Company is merged or the Person which acquires by conveyance, transfer or
     lease substantially all of the assets of the Company as an entirety shall
     execute and deliver to the Trustee applicable to the Certificates of each
     series a duly authorized, valid, binding and enforceable agreement in form
     and substance reasonably satisfactory to the Trustee containing an
     assumption by such successor corporation or Person of the due and punctual
     performance and observance of each covenant and condition of the Note
     Documents and of this Agreement applicable to the Certificates of each
     series to be performed or observed by the Company;

          (c) immediately after giving effect to such transaction, no Event of
     Default applicable to the Certificates of each series or event which is, or
     after notice or passage of time, or both, would be, such an Event of
     Default shall have occurred and be continuing; and

          (d) the Company shall have delivered to the Trustee an Officers'
     Certificate of the Company and an Opinion of Counsel of the Company
     reasonably satisfactory to the Trustee, each stating that such
     consolidation, merger, conveyance, transfer or lease and the assumption
     agreement mentioned in clause (b) above comply with this Section 5.02 and
     that all conditions precedent herein provided for relating to such
     transaction have been complied with.

          Upon any consolidation or merger, or any conveyance, transfer or lease
of substantially all of the assets of the Company as an entirety in accordance
with this Section 5.02, the successor corporation or Person formed by such
consolidation or into which the Company is merged or to which such conveyance,
transfer or lease is made shall succeed to, and be substituted for, and may
exercise every right and power of, the Company under this Agreement applicable
to the Certificates of each series with the same effect as if such successor
corporation or Person had been named as the Company herein.  No such conveyance,
transfer or lease of substantially all of the assets of the Company as an
entirety shall have the effect of releasing the Company or any successor
corporation or Person which shall theretofore have become such in the manner
prescribed in this Section 5.02 from its liability in respect of any Note
Document and of this Agreement applicable to the Certificates of such series to
which it is a party.

                                  ARTICLE VI

                                    DEFAULT

          Section  6.01.   Events of Default.  If, in respect of any Trust, any
                           -----------------                                   
Indenture Default under any related Indenture shall occur and be continuing,
then, in each and every case, so long as such Event of Default shall be
continuing, the Trustee may (a) vote all

 
                                      29


Equipment Notes issued under the relevant Indenture held in such Trust, and upon
the direction of the Certificateholders holding Certificates evidencing
Fractional Undivided Interests in such Trust aggregating not less than a
majority in interest in such Trust, the Trustee shall vote not less than a
corresponding majority of such Equipment Notes in favor of directing the Loan
Trustee under such Indenture to declare the unpaid principal amount of the
Equipment Notes then outstanding to which such Event of Default relates and
accrued interest thereon to be due and payable under, and in accordance with the
provisions of, such Indenture, and (b) may in accordance with the provisions of
the relevant Indenture vote such Equipment Notes held in such Trust to direct
the Loan Trustee regarding the exercise of remedies provided in such Indenture.

          In addition, after an Indenture Default shall have occurred and be
continuing with respect to any Equipment Note held in a Trust, the Trustee
therein may in its discretion, and upon the direction of the Certificateholders
holding Certificates evidencing Fractional Undivided Interests aggregating not
less than a majority in interest in such Trust shall, by such officer or agent
as it may appoint, sell, convey, transfer and deliver such Equipment Note,
without recourse to or warranty by the Trustee or any Certificateholder, to any
Person.  In any such case, the Trustee shall sell, assign, contract to sell or
otherwise dispose of and deliver such Equipment Note or Equipment Notes in one
or more parcels at public or private sale or sales, at any location or locations
at the option of the Trustee, all upon such terms and conditions as it may
reasonably deem advisable and at such prices as it may reasonably deem
advisable, for cash.  If the Trustee so decides or is required to sell or
otherwise dispose of any Equipment Note pursuant to this Section, the Trustee
shall take such of the actions described above as it may reasonably deem most
effectual to complete the sale or other disposition of such Equipment Note, so
as to provide for the payment in full of all amounts due on the related series
of Certificates.  Notwithstanding the foregoing, any action taken by the Trustee
under this Section shall not, in the reasonable judgment of the Trustee, be
adverse to the best interests of the Certificateholders of such series.

          Section 6.02.  Incidents of Sale of Equipment Notes.  Upon any sale of
                         ------------------------------------                   
all or any part of the Equipment Notes made either under the power of sale given
under this Agreement or otherwise for the enforcement of this Agreement, the
following shall be applicable:

          (1) Certificateholders and Trustee May Purchase Equipment Notes.  Any
              -----------------------------------------------------------      
     Certificateholder, the Trustee in its individual or any other capacity or
     any other Person may bid for and purchase any of the Equipment Notes, and
     upon compliance with the terms of sale, may hold, retain, possess and
     dispose of such Equipment Notes in its own absolute right without further
     accountability.

          (2) Receipt of Trustee Shall Discharge Purchaser.  The receipt of the
              --------------------------------------------                     
     Trustee or of the officer making such sale shall be a sufficient discharge
     to any

 
                                      30


     purchaser for his purchase money, and, after paying such purchase money and
     receiving such receipt, such purchaser or its personal representative or
     assigns shall not be obliged to see to the application of such purchase
     money, or be in any way answerable for any loss, misapplication or non-
     application thereof.

          (3) Application of Moneys Received upon Sale.  Any moneys collected by
              ----------------------------------------                          
     the Trustee upon any sale made either under the power of sale given by this
     Agreement or otherwise for the enforcement of this Agreement shall be
     applied as provided in Section 4.02.

          Section 6.03.  Judicial Proceedings Instituted by Trustee; Trustee May
                         -------------------------------------------------------
Bring Suit.  If there shall be a failure to make payment of the principal of,
- ----------                                                                   
premium, if any, or interest on any Equipment Note, or if there shall be any
failure to pay Rent (as defined in the relevant Lease) under any Lease when due
and payable, then the Trustee, in its own name, and as trustee of an express
trust, as holder of such Equipment Notes, to the extent permitted by and in
accordance with the terms of the Note Documents, shall be entitled and empowered
to institute any suits, actions or proceedings at law, in equity or otherwise,
for the collection of the sums so due and unpaid on such Equipment Notes or
under such Lease and may prosecute any such claim or proceeding to judgment or
final decree with respect to the whole amount of any such sums so due and
unpaid.

          Section 6.04.  Control by Certificateholders.  Subject to Section
                         -----------------------------                     
6.03, the Certificateholders holding Certificates evidencing Fractional
Undivided Interests aggregating not less than a majority in interest in the
related Trust shall have the right to direct the time, method and place of
conducting any proceeding for any remedy available to the Trustee with respect
to such Trust, or exercising any trust or power conferred on the Trustee under
this Agreement, including any right of the Trustee as holder of the Equipment
Notes, provided that
       --------     

          (1) such direction shall not be in conflict with any rule of law or
     with this Agreement and would not involve the Trustee in personal liability
     or expense,

          (2) the Trustee shall not determine that the action so directed would
     be unjustly prejudicial to the Certificateholders of such series not taking
     part in such direction,

          (3) the Trustee may take any other action deemed proper by the Trustee
     which is not inconsistent with such direction, and

          (4) if an Indenture Default under a related Indenture shall have
     occurred and be continuing, such direction shall not obligate the Trustee
     to vote more than a corresponding majority of the related Equipment Notes
     held by the Trust in favor of

 
                                      31


     directing any action by the related Loan Trustee with respect to such
     Indenture Default.

          Section 6.05.  Waiver of Past Defaults.  The Certificateholders
                         -----------------------                         
holding Certificates of a Series evidencing Fractional Undivided Interests
aggregating not less than a majority in interest in the related Trust may on
behalf of all of the Certificateholders of such series waive any past Event of
Default hereunder or under the related Trust Supplement with respect to such
series and its consequences or may instruct the Trustee to waive any past
default under the related Indenture or this Agreement or the related Trust
Supplement with respect to such series and its consequences, except a default:

          (1) in the deposit of any Scheduled Payment or Special Payment under
     Section 4.01 or in the distribution of any payment under Section 4.02 on
     the Certificates of such series, or

          (2) in the payment of the principal of (premium, if any) or interest
     on the Equipment Notes, or

          (3) in respect of a covenant or provision hereof which under Article
     IX hereof cannot be modified or amended without the consent of each
     Certificateholder holding an Outstanding Certificate of such series
     affected.

          Upon any such waiver, such default shall cease to exist with respect
to the Certificates of such series and any Event of Default arising therefrom
shall be deemed to have been cured for every purpose in respect of such series
and any direction given by the Trustee on behalf of the Certificateholders of
such series to the relevant Loan Trustee shall be annulled with respect thereto;
but no such waiver shall extend to any subsequent or other default or Event of
Default or impair any right consequent thereon.  Upon any such waiver, the
Trustee shall vote the Equipment Notes issued under the relevant Indenture to
waive the corresponding Indenture Default.

          Section 6.06.  Right of Certificateholders to Receive Payments Not to
                         ------------------------------------------------------
Be Impaired.  Anything in this Agreement to the contrary notwithstanding,
- -----------                                                              
including, without limitation, Section 6.07 hereof, the right of any
Certificateholder to receive distributions of payments required pursuant to
Section 4.02 hereof on the applicable Certificates when due, or to institute
suit for the enforcement of any such payment on or after the applicable Regular
Distribution Date or Special Distribution Date, shall not be impaired or
affected without the consent of such Certificateholder.

          Section 6.07.  Certificateholders May Not Bring Suit Except Under
                         --------------------------------------------------
Certain Conditions.  A Certificateholder of any series shall not have the right
- ------------------                                                             
to institute any suit, action or proceeding at law or in equity or otherwise
with respect to this Agreement, for the

 
                                      32


appointment of a receiver or for the enforcement of any other remedy under this
Agreement, unless:

          (1) such Certificateholder previously shall have given written notice
     to the Trustee of a continuing Event of Default;

          (2) the Certificateholders holding Certificates of such series
     evidencing Fractional Undivided Interests aggregating not less than 25% of
     the related Trust shall have requested the Trustee in writing to institute
     such action, suit or proceeding and shall have offered to the Trustee
     indemnity as provided in Section 7.02(e);

          (3) the Trustee shall have refused or neglected to institute an such
     action, suit or proceeding for 60 days after receipt of such notice,
     request and offer of indemnity; and

          (4) no direction inconsistent with such written request shall have
     been given to the Trustee during such 60-day period by the
     Certificateholders holding Certificates of such series evidencing
     Fractional Undivided Interests aggregating not less than a majority in
     interest in the related Trust.

          It is understood and intended that no one or more of the
Certificateholders of any series shall have any right in any manner whatsoever
hereunder or under the related Trust Supplement or under the Certificates of
such series to (i) surrender, impair, waive, affect, disturb or prejudice any
property in the Trust Property of the related Trust or the lien of any related
Indenture on any property subject thereto, or the rights of the
Certificateholders of such series or the holders of the related Equipment Notes,
(ii) obtain or seek to obtain priority over or preference with respect to any
other such Certificateholder of such series or (iii) enforce any right under
this Agreement, except in the manner herein provided and for the equal, ratable
and common benefit of all the Certificateholders of such series subject to the
provisions of this Agreement.

          Section 6.08.  Remedies Cumulative.  Every remedy given hereunder to
                         -------------------                                  
the Trustee or to any of the Certificateholders of any series shall not be
exclusive of any other remedy or remedies, and every such remedy shall be
cumulative and in addition to every other remedy given hereunder or now or
hereafter given by statute, law, equity or otherwise.

 
                                      33


                                  ARTICLE VII

                                  THE TRUSTEE


          Section 7.01.  Notice of Defaults.  As promptly as practicable after,
                         ------------------                                    
and in any event within 90 days after, the occurrence of any default (as such
term is defined below) hereunder, the Trustee shall transmit by mail to the
Company, any related Owner Trustees, the related Loan Trustees and the
Certificateholders holding Certificates of the related series in accordance with
Section 313(c) of the Trust Indenture Act, notice of such default hereunder
known to the Trustee, unless such default shall have been cured or waived;
provided, however, that, except in the case of a default on the payment of the
- --------  -------                                                             
principal of (premium, if any) or interest on any Equipment Note, the Trustee
shall be protected in withholding such notice if and so long as the board of
directors, the executive committee or a trust committee of directors and/or
Responsible Officers of the Trustee in good faith determine that the withholding
of such notice is in the interests of the Certificateholders of the related
series.  For the purpose of this Section in respect of any Trust, the term
"default" means any event that is, or after notice or lapse of time or both
would become, an Event of Default in respect of that Trust.

          Section 7.02.  Certain Rights of Trustee. Subject to the provisions 
                         -------------------------
of Section 315 of the Trust Indenture Act:

          (a) the Trustee may rely and shall be protected in acting or
     refraining from acting in reliance upon any resolution, certificate,
     statement, instrument, opinion, report, notice, request, direction,
     consent, order, bond, debenture or other paper or document believed by it
     to be genuine and to have been signed or presented by the proper party or
     parties;

          (b) any request or direction of the Company mentioned herein shall be
     sufficiently evidenced by a Request;

          (c) whenever in the administration of this Agreement the Trustee shall
     deem it desirable that a matter be proved or established prior to taking,
     suffering or omitting any action hereunder, the Trustee (unless other
     evidence be herein specifically prescribed) may, in the absence of bad
     faith on its part, rely upon an Officers' Certificate of the Company, any
     related Owner Trustee or any related Loan Trustee;

          (d) the Trustee may consult with counsel and the advice of such
     counsel or any Opinion of Counsel shall be full and complete authorization
     and protection in

 
                                      34


     respect of any action taken, suffered or omitted by it hereunder in good
     faith and in reliance thereon;

          (e) the Trustee shall be under no obligation to exercise any of the
     rights or powers vested in it by this Agreement at the request or direction
     of any of the Certificateholders pursuant to this Agreement, unless such
     Certificateholders shall have offered to the Trustee reasonable security or
     indemnity against the cost, expenses and liabilities which might be
     incurred by it in compliance with such request or direction;

          (f) the Trustee shall not be bound to make any investigation into the
     facts or matters stated in any resolution, certificate, statement,
     instrument, opinion, report, notice, request, direction, consent, order,
     bond, debenture or other paper or document;

          (g) the Trustee may execute any of the trusts or powers under this
     Agreement or perform any duties under this Agreement either directly or by
     or through agents or attorneys and the Trustee shall not be responsible for
     any misconduct or negligence on the part of any agent or attorney appointed
     with due care by it under this Agreement;

          (h) the Trustee shall not be liable with respect to any action taken
     or omitted to be taken by it in good faith in accordance with the direction
     of the Certificateholders holding Certificates of any series evidencing
     Fractional Undivided Interests aggregating not less than a majority in
     interest in the related Trust relating to the time, method and place of
     conducting any proceeding for any remedy available to the Trustee, or
     exercising any trust or power conferred upon the Trustee, under this
     Agreement; and

          (i) the Trustee shall not be required to expend or risk its own funds
     in the performance of any of its duties under this Agreement, or in the
     exercise of any of its rights or powers, if it shall have reasonable
     grounds for believing that repayment of such funds or adequate indemnity
     against such risk is not reasonably assured to it.

          Section 7.03.  Not Responsible for Recitals or Issuance of
                         -------------------------------------------
Certificates.  The recitals contained herein and in the Certificates of each
- ------------                                                                
series, except the certificates of authentication, shall not be taken as the
statements of the Trustee, and the Trustee assumes no responsibility for their
correctness.  Subject to Section 7.14, the Trustee makes no representations as
to the validity or sufficiency of this Basic Agreement or any Trust Supplement,
any Note Documents, any Note Purchase Agreement, any Equipment Notes or the
Certificates of any series, except that the Trustee hereby represents and
warrants that this Basic Agreement has been, and each Trust Supplement and each
Certificate of each series to

 
                                      35


which such Trustee is a party  will be, executed and delivered by one of its
officers who is duly authorized to execute and deliver such document on its
behalf.

          Section 7.04.  May Hold Certificates.  The Trustee, any Paying Agent,
                         ---------------------                                 
Registrar or any of their Affiliates or any other agent in their respective
individual or any other capacity, may become the owner or pledgee of
Certificates and, subject to Sections 310(b) and 311 of the Trust Indenture Act,
may otherwise deal with the Company, any Owner Trustees or the Loan Trustees
with the same rights it would have if it were not Trustee, Paying Agent,
Registrar or such other agent.

          Section 7.05.  Money Held in Trust.  Money held by the Trustee or the
                         -------------------                                   
Paying Agent in trust hereunder or under any Trust Supplement need not be
segregated from other funds except to the extent required herein or by law and
neither the Trustee nor the Paying Agent shall have any liability for interest
upon any such moneys except as provided for herein.

          Section 7.06.  Compensation and Reimbursement.  The Company agrees:
                         ------------------------------                      

          (1) to pay, or cause to be paid, to the Trustee from time to time
     reasonable compensation for all services rendered by it hereunder (which
     compensation shall not be limited by any provision of law in regard to the
     compensation of a trustee of an express trust); and

          (2) except as otherwise expressly provided herein or in any Trust
     Supplement, to reimburse, or cause to be reimbursed, the Trustee upon its
     request for all reasonable out-of-pocket expenses, disbursements and
     advances incurred or made by the Trustee in accordance with any provision
     of this Basic Agreement or any Trust Supplement (including the reasonable
     compensation and the expenses and disbursements of its agents and counsel),
     except any such expense, disbursement or advance as may be attributable to
     its negligence, willful misconduct or bad faith or as may be incurred due
     to the Trustee's breach of its representations and warranties set forth in
     Section 7.14.

          The Trustee shall be entitled to reimbursement from, and shall have a
lien prior to the Certificates of each series upon, all property and funds held
or collected by the Trustee in its capacity as Trustee with respect to such
series or the related Trust for any tax incurred without negligence, bad faith
or willful misconduct, on its part, arising out of or in connection with the
acceptance or administration of such Trust (other than any tax attributable to
the Trustee's compensation for serving as such), including any costs and
expenses incurred in contesting the imposition of any such tax.  If the Trustee
reimburses itself from the Trust Property of such Trust for any such tax it,
will within 30 days mail a

 
                                      36


brief report setting forth the circumstances thereof to all Certificateholders
of such series as their names and addresses appear in the Register.

          As security for the performance of the obligations of the Company
under this Section with respect to each Trust the Trustee shall have a lien
prior to the Certificates of the related series upon all property and funds held
or collected by the Trustee in its capacity as Trustee with respect to such
Certificates and the related Trust.

          Section 7.07.  Corporate Trustee Required; Eligibility.  Each Trust
                         ---------------------------------------             
shall at all times have a Trustee which shall be eligible to act as a trustee
under Section 310(a) of the Trust Indenture Act and shall have a combined
capital and surplus of at least $75,000,000 (or having a combined capital and
surplus in excess of $5,000,000 (or, in respect of State Street Bank and Trust
Company of Connecticut, National Association as Trustee, $3,000,000) and the
obligations of which, whether now in existence or hereafter incurred, are fully
and unconditionally guaranteed by a corporation organized and doing business
under the laws of the United States, any State or Territory thereof or of the
District of Columbia and having a combined capital and surplus of at least
$75,000,000).  If such corporation publishes reports of conditions at least
annually, pursuant to law or to the requirements of Federal, State, Territorial
or District of Columbia supervising or examining authority, then for the
purposes of this Section 7.07, the combined capital and surplus of such
corporation shall be deemed to be its combined capital and surplus as set forth
in its most recent report of conditions so published.

          In case at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section 7.07 to act as Trustee of any
Trust, the Trustee shall resign immediately as Trustee of such Trust in the
manner and with the effect specified in Section 7.08.

          Section 7.08.  Resignation and Removal; Appointment of Successor.  
                         -------------------------------------------------
(a) No resignation or removal of the Trustee and no appointment of a successor
Trustee of any Trust pursuant to this Article shall become effective until the
acceptance of appointment by the successor Trustee under Section 7.09.

          (b) The Trustee may resign at any time as trustee of any or all Trusts
by giving written notice thereof to the Company, the Authorized Agents, the
related Owner Trustees and the related Loan Trustees.  If an instrument of
acceptance by a successor Trustee shall not have been delivered to the Company,
the related Owner Trustees and the Trustee within 30 days after the giving of
such notice of resignation, the resigning Trustee may petition any court of
competent jurisdiction for the appointment of a successor Trustee.

          (c) The Trustee may be removed at any time as trustee of any Trust by
Act of the Certificateholders of the related series holding Certificates of such
series evidencing

 
                                      37


Fractional Undivided Interests aggregating not less than a majority in interest
in such Trust delivered to the Trustee and to the Company, the related Owner
Trustees and the related Loan Trustees.

          (d) If at any time in respect of any Trust:

          (1) the Trustee shall fail to comply with Section 310 of the Trust
     Indenture Act after written request therefor by the Company or by any
     Certificateholder of the related series who has been a bona fide
     Certificateholder for at least six months; or

          (2) the Trustee shall cease to be eligible under Section 7.07 and
     shall fail to resign after written request therefor by the Company or by
     any such Certificateholder; or

          (3) the Trustee shall become incapable of acting or shall be adjudged
     a bankrupt or insolvent or a receiver of the Trustee or of its property
     shall be appointed or any public officer shall take charge or control of
     the Trustee or of its property or affairs for the purpose of
     rehabilitation, conservation or liquidation;

then, in any case, (i) the Company may remove the Trustee or (ii) any
Certificateholder of the related series who has been a bona fide
Certificateholder for at least six months may, on behalf of itself and all
others similarly situated, petition any court of competent jurisdiction for the
removal of the Trustee and the appointment of a successor Trustee of such Trust.

          (e) If a Responsible Officer of the Trustee shall obtain actual
knowledge of an Avoidable Tax (as hereinafter defined) in respect of any Trust
which has been or is likely to be asserted, the Trustee shall promptly notify
the Company and shall, within 30 days of such notification, resign as Trustee of
such Trust hereunder unless within such 30-day period the Trustee shall have
received notice that the Company has agreed to pay such tax.  The Company shall
promptly appoint a successor Trustee of such Trust in a jurisdiction where there
are no Avoidable Taxes.  As used herein, an "Avoidable Tax" in respect of such
Trust means a state or local tax:  (i) upon (w) such Trust, (x) such Trust
Property, (y) Certificateholders of such Trust or (z) the Trustee for which the
Trustee is entitled to seek reimbursement from the Trust Property of such Trust,
and (ii) which would be avoided if the Trustee were located in another state, or
jurisdiction within a state, within the United States.  A tax shall not be an
Avoidable Tax in respect of any Trust if the Company or any Owner Trustee shall
agree to pay, and shall pay, such tax.

          (f) If the Trustee shall resign, be removed or become incapable of
acting as trustee of any Trust, or if a vacancy shall occur in the office of the
Trustee of any Trust for any cause, the Company shall promptly appoint a
successor Trustee of such Trust.  If, within one year after such resignation,
removal or incapability, or other occurrence of such

 
                                      38


vacancy, a successor Trustee of such Trust shall be appointed by Act of the
Certificateholders of the related series holding Certificates of such series
evidencing Fractional Undivided Interests aggregating not less than a majority
in interest in such Trust delivered to the Company, the related owner Trustees,
the related Loan Trustee and the retiring Trustee, then the successor Trustee so
appointed shall, with the approval of the Company, which approval shall not be
unreasonably withheld, forthwith upon its acceptance of such appointment, become
the successor Trustee of such Trust and supersede the successor Trustee of such
Trust appointed as provided above.  If no successor Trustee shall have been so
appointed as provided above and accepted appointment in the manner hereinafter
provided, any Certificateholder who has been a bona fide Certificateholder of
the related series for at least six months may, on behalf of himself and all
others similarly situated, petition any court of competent jurisdiction for the
appointment of a successor Trustee of such Trust.

          (g) The successor Trustee of a Trust shall give notice of the
resignation and removal of the Trustee and appointment of the successor Trustee
by mailing written notice of such event by first-class mail, postage prepaid, to
the Certificateholders of the related series as their names and addresses appear
in the Register.  Each notice shall include the name of such successor Trustee
and the address of its Corporate Trust Office.

          Section 7.09.  Acceptance of Appointment by Successor.  Every
                         --------------------------------------        
successor Trustee appointed hereunder shall execute and deliver to the Company
and to the retiring Trustee with respect to any or all Trusts an instrument
accepting such appointment, and thereupon the resignation or removal of the
retiring Trustee with respect to such Trusts shall become effective and such
successor Trustee, without any further act, deed or conveyance, shall become
vested with all the rights, powers, trusts and duties of the retiring Trustee;
but, on request of the Company or the successor Trustee, such retiring Trustee
shall execute and deliver an instrument transferring to such successor Trustee
all such rights, powers and trusts of the retiring Trustee and shall duly
assign, transfer and deliver to such successor Trustee all property and money
held by such retiring Trustee in respect of such Trusts hereunder, subject
nevertheless to its lien, if any, provided for in Section 7.06.  Upon request of
any such successor Trustee, the Company, the retiring Trustee and such successor
Trustee shall execute and deliver any and all instruments containing such
provisions as shall be necessary or desirable to transfer and confirm to, and
for more fully and certainly vesting in, such successor Trustee all such rights,
powers and trusts.

          If a successor Trustee is appointed with respect to one or more (but
not all) Trusts, the Company, the predecessor Trustee and each successor Trustee
with respect to any Trust shall execute and deliver a supplemental agreement
hereto which shall contain such provisions as shall be deemed necessary or
desirable to confirm that all the rights, powers, trusts and duties of the
predecessor Trustee with respect to the Trusts as to which the predecessor
Trustee is not retiring shall continue to be vested in the predecessor Trustee,
and

 
                                      39


shall add to or change any of the provisions of this Basic Agreement and the
applicable Trust Supplements as shall be necessary to provide for or facilitate
the administration of the Trusts hereunder by more than one Trustee.

          It is understood that nothing herein or in any supplemental agreement
or Trust Supplement shall constitute any Trustee a co-Trustee of the same Trust
and that each  Trustee shall be the Trustee of one or more separate Trusts.

          No institution shall accept its appointment as a Trustee hereunder
unless at the time of such acceptance such institution shall be qualified and
eligible under this Article.

          Section 7.10.  Merger, Conversion, Consolidation or Succession to
                         --------------------------------------------------
Business.  Any corporation into which the Trustee may be merged or converted or
- --------                                                                       
with which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to all or substantially all of the corporate trust
business of the Trustee, shall be the successor of the Trustee hereunder,
provided such corporation shall be otherwise qualified and eligible under this
- --------                                                                      
Article, without the execution or filing of any paper or any further act on the
part of any of the parties hereto.  In case any Certificates shall have been
executed or authenticated, but not delivered, by the Trustee then in office, any
successor by merger, conversion or consolidation to such authenticating Trustee
may adopt such execution or authentication and deliver the Certificates so
executed or authenticated with the same effect as if such successor Trustee had
itself executed or authenticated such Certificates.

          Section 7.11.  Maintenance of Agencies.  (a)  With respect to each
                         -----------------------                            
series of Certificates, there shall at all times be maintained an office or
agency in the location set forth in Section 12.03 hereof; (provided that such
office or agency shall, as to State Street Bank and Trust Company of
Connecticut, National Association, be at State Street Bank and Trust Company,
National Association, 61 Broadway, New York, New York 10006) where Certificates
of such series may be presented or surrendered for registration of transfer or
for exchange, and for payment thereof and where notices and demands to or upon
the Trustee in respect of such certificates or of the related Trust Supplement
may be served; provided, however, that, if it shall be necessary that the
               --------  -------                                         
Trustee maintain an office or agency in another location (e.g., the Certificates
shall be represented by definitive certificates and shall be listed on a
national securities exchange), the Trustee will make all reasonable efforts to
establish such an office.  Written notice of the location of each such other
office or agency and of any change of location thereof shall be given by the
Trustee to the Company, any Owner Trustees, the Loan Trustees and the
Certificateholders of such series.  In the event that no such office or agency
shall be maintained or no such notice of location or of change of location shall
be given, presentations and demands may be made and notices may be served at the
Corporate Trust Office of the Trustee.

 
                                      40


          (b) There shall at all times be a Registrar and a Paying Agent
hereunder with respect to the Certificates of each series.  Each such Authorized
Agent shall be a bank or trust company, shall be a corporation organized and
doing business under the laws of the United States or any state, with a combined
capital and surplus of at least $75,000,000, or, if the Trustee shall be acting
as the Registrar or Paying Agent hereunder, a corporation the obligations of
which are guaranteed by a corporation organized and doing business under the
laws of the United States or any state, with a combined capital and surplus of
at least $75,000,000 (or having a combined capital and surplus in excess of
$5,000,000 (or, in respect of State Street Bank and Trust Company of
Connecticut, National Association as Trustee, $3,000,000)), and shall be
authorized under such laws to exercise corporate trust powers, subject to
supervision by Federal or state authorities.  The Trustee shall initially be the
Paying Agent and, as provided in Section 3.04, Registrar hereunder with respect
to the Certificates of each series.  Each Registrar shall furnish to the
Trustee, at stated intervals of not more than six months, and at such other
times as the Trustee may request in writing, a copy of the Register maintained
by such Registrar.

          (c) Any corporation into which any Authorized Agent may be merged or
converted or with which it may be consolidated, or any corporation resulting
from any merger, consolidation or conversion to which any Authorized Agent shall
be a party, or any corporation succeeding to the corporate trust business of any
Authorized Agent, shall be the successor of such Authorized Agent hereunder, if
such successor corporation is otherwise eligible under this Section, without the
execution or filing of any paper or any further act on the part of the parties
hereto or such Authorized Agent or such successor corporation.

          (d) Any Authorized Agent may at any time resign by giving written
notice of resignation to the Trustee, the Company, any related Owner Trustees
and the related Loan Trustees.  The Company may, and at the request of the
Trustee shall, at any time terminate the agency of any Authorized Agent by
giving written notice of termination to such Authorized Agent and to the
Trustee.  Upon the resignation or termination of an Authorized Agent or in case
at any time any such Authorized Agent shall cease to be eligible under this
Section (when, in either case, no other Authorized Agent performing the
functions of such Authorized Agent shall have been appointed), the Company shall
promptly appoint one or more Qualified successor Authorized Agents, reasonably
satisfactory to the Trustee, to perform the functions of the Authorized Agent
which has resigned or whose agency has been terminated or who shall have ceased
to be eligible under this Section.  The Company shall give written notice of any
such appointment made by it to the Trustee, any related Owner Trustees and the
related Loan Trustees; and in each case the Trustee shall mail notice of such
appointment to all Certificateholders of the related series as their names and
addresses appear on the Register for such series.

 
                                      41


          (e) The Company agrees to pay, or cause to be paid, from time to time
to each Authorized Agent reasonable compensation for its services and to
reimburse it for its reasonable expenses.

          Section 7.12.  Money for Certificate Payments to Be Held in Trust.
                         --------------------------------------------------  
All moneys deposited with any Paying Agent for the purpose of any payment on
Certificates shall be deposited and held in trust for the benefit of the
Certificateholders entitled to such payment, subject to the provisions of this
Section.  Moneys so deposited and held in trust shall constitute a separate
trust fund for the benefit of the Certificateholders with respect to which such
money was deposited.

          The Trustee may at any time, for the purpose of obtaining the
satisfaction and discharge of this Agreement or for any other purpose, direct
any Paying Agent to pay to the Trustee all sums held in trust by such Paying
Agent, such sums to be held by the Trustee upon the same trusts as those upon
which such sums were held by such Paying Agent; and, upon such payment by any
Paying Agent to the Trustee, such Paying Agent shall be released from all
further liability with respect to such money.

          Section 7.13.  Registration of Equipment Notes in Trustee's Name.  The
                         -------------------------------------------------      
Trustee agrees that all Equipment Notes, and Permitted Investments, if any,
shall be issued in the name of the Trustee as trustee for the applicable Trust
or its nominee and held by the Trustee, or, if not so held, the Trustee or its
nominee shall be reflected as the owner of such Equipment Notes or Permitted
Investments as the case may be, in the register of the issuer of such Equipment
Notes or Permitted Investments.  In no event shall the Trustee invest in, or
hold, Equipment Notes or Permitted Investments in a manner that would cause the
Trustee not to have the ownership interest in such Equipment Notes or Permitted
Investments under the applicable provisions of the Uniform Commercial Code in
effect where the Trustee holds such Equipment Notes or Permitted Investments or
other applicable law then in effect.

          Section 7.14.  Representations and Warranties of Trustee.  The Trustee
                         -----------------------------------------              
hereby represents and warrants that:

          (i) the Trustee is a national banking association or a bank or trust
     company organized or chartered under the law of a state of the United
     States and duly organized, validly existing and in good standing under the
     laws of the United States or such state, as the case may be;

          (ii) the Trustee has full power, authority and legal right to execute,
     deliver, and perform this Basic Agreement and has taken all necessary
     action to authorize the execution, delivery, and performance by it of this
     Basic Agreement;

 
                                      42


          (iii)  the execution delivery and performance by the Trustee of this
     Basic Agreement (a) will not violate any provision of United States federal
     law or the law of the state of the United States where it is located
     governing the banking and trust powers of the Trustee or any order, writ,
     judgment, or decree of any court, arbitrator or governmental authority
     applicable to the Trustee or any of its assets, (b) will not violate any
     provision of the articles of association or by-laws of the Trustee, or (c)
     will not violate any provision of, or constitute, with or without notice or
     lapse of time, a default under, or result in the creation or imposition of
     any lien on any properties included in the Trust Property of any Trust
     pursuant to the provisions of any mortgage, indenture, contract, agreement
     or other undertaking to which it is a party, which violation, default or
     lien could reasonably be expected to have an adverse effect on the
     Trustee's performance or ability to perform its duties hereunder or
     thereunder or on the transactions contemplated herein or therein;

          (iv) the execution, delivery and performance by the Trustee of this
     Basic Agreement will not require the authorization, consent, or approval
     of, the giving of notice to, the filing or registration with, or the taking
     of any other action in respect of, any governmental authority or agency of
     the United States or the State of the United States where it is located
     regulating the banking and corporate trust activities of the Trustee; and

          (v) this Basic Agreement has been duly executed and delivered by the
     Trustee and constitutes the legal, valid, and binding agreement of the
     Trustee, enforceable against it in accordance with its terms, provided that
     enforceability may be limited by (i) applicable bankruptcy, insolvency,
     reorganization, moratorium or similar laws affecting the rights of
     creditors generally and (ii) general principles of equity.

          Section 7.15.  Withholding Taxes; Information Reporting.  As to the
                         ----------------------------------------            
Certificates of any series, the Trustee, as trustee of the related grantor trust
created by this Agreement, shall exclude and withhold from each distribution of
principal, premium, if any, and interest and other amounts due under this
Agreement or under the Certificates of such series any and all withholding taxes
applicable thereto as required by law.  The Trustee agrees to act as such
withholding agent and, in connection therewith, whenever any present or future
taxes or similar charges are required to be withheld with respect to any amounts
payable in respect of the Certificates of such series, to withhold such amounts
and timely pay the same to the appropriate authority in the name of and on
behalf of the Certificateholders of such series, that it will file any necessary
withholding tax returns or statements when due, and that, as promptly as
possible after the payment thereof, it will deliver to each such
Certificateholder appropriate documentation showing the payment thereof,
together with such additional documentary evidence as such Certificateholders of
such series may reasonably

 
                                      43


request from time to time.  The Trustee agrees to file any other information
reports as it may be required to file under United States law.

          Section 7.16.  Trustee's Liens.  The Trustee in its individual
                         ---------------                                
capacity agrees that it will, in respect of each Trust created by this Agreement
at its own cost and expense promptly take any action as may be necessary to duly
discharge and satisfy in full any mortgage, pledge, lien, charge, encumbrance,
security interest or claim ("Trustee's Liens") on or with respect to the Trust
Property of such Trust which is attributable to the Trustee either (i) in its
individual capacity and which is unrelated to the transactions contemplated by
this Agreement, the related Note Purchase Agreements or the related Note
Documents, or (ii) as Trustee hereunder or in its individual capacity and which
arises out of acts or omissions which are not contemplated by this Agreement.


                                 ARTICLE VIII

               CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE

          Section 8.01.  The Company to Furnish Trustee with Names and Addresses
                         -------------------------------------------------------
of Certificateholders.  The Company will furnish to the Trustee within 15 days
- ---------------------                                                         
after each Record Date with respect to a Scheduled Payment, and at such other
times as the Trustee may request in writing, within 30 days after receipt by the
Company of any such request, a list, in such form as the Trustee may reasonably
require, of all information in the possession or control of the Company as to
the names and addresses of the Certificateholders of such series, in each case
as of a date not more than 15 days prior to the time such list is furnished;
provided, however, that so long as the Trustee is the sole Registrar for such
- --------  -------                                                            
series, no such list need be furnished; and provided further, however, that no
                                            -------- -------  -------         
such list need be furnished for so long as a copy of the Register is being
furnished to the Trustee pursuant to Section 7.11.

          Section 8.02.  Preservation of Information; Communications to
                         ----------------------------------------------
Certificateholders.  The Trustee shall preserve, in as current a form as is
- ------------------                                                         
reasonably practicable, the names and addresses of Certificateholders of each
series contained in the most recent list furnished to the Trustee as provided in
Section 7.11 or Section 8.01, as the case may be, and the names and addresses of
Certificateholders of each series received by the Trustee in its capacity as
Registrar, if so acting.  The Trustee may destroy any list furnished to it as
provided in Section 7.11 or Section 8.01, as the case may be, upon receipt of a
new list so furnished.

          Section 8.03.  Reports by Trustee.  Within 60 days after May 15 of
                         ------------------                                 
each year commencing with the first full year following the issuance of any
series of Certificates, the Trustee shall transmit to the Certificateholders of
each series, as provided in Section 313(c)

 
                                      44


of the Trust Indenture Act, a brief report dated as of such May 15, if required
by Section 313(a) of the Trust Indenture Act.

          Section 8.04.  Reports by the Company.  The Company shall:
                         ----------------------                     

          (a) file with the Trustee, within 30 days after the Company is
     required to file the same with the SEC, copies of the annual reports and of
     the information, documents and other reports (or copies of such portions of
     any of the foregoing as the SEC may from time to time by rules and
     regulations prescribe) which the Company is required to file with the SEC
     pursuant to section 13 or section 15(d) of the Securities Exchange Act of
     1934, as amended; or, if the Company is not required to file information,
     documents or reports pursuant to either of such sections, then to file with
     the Trustee and the SEC, in accordance with rules and regulations
     prescribed by the SEC, such of the supplementary and periodic information,
     documents and reports which may be required pursuant to section 13 of the
     Securities Exchange Act of 1934, as amended, in respect of a security
     listed and registered on a national securities exchange as may be
     prescribed in such rules and regulations;

          (b) file with the Trustee and the SEC, in accordance with the rules
     and regulations prescribed by the SEC, such additional information,
     documents and reports with respect to compliance by the Company with the
     conditions and covenants provided for in this Agreement, as may be required
     by such rules and regulations, including, in the case of annual reports, if
     required by such rules and regulations, certificates or opinions of
     independent public accountants;

          (c) transmit to all Certificateholders, in the manner and to the
     extent provided in Section 313(c) of the Trust Indenture Act such summaries
     of any information, documents and reports required to be filed by the
     Company pursuant to subsections (a) and (b) of this Section 8.04 as may be
     required by rules and regulations prescribed by the SEC; and

          (d) furnish to the Trustee, not less often than annually, a brief
     certificate from the principal executive officer, principal financial
     officer or principal accounting officer as to his or her knowledge of the
     Company's compliance with all conditions and covenants under this Agreement
     (it being understood that for purposes of this paragraph (d), such
     compliance shall be determined without regard to any period of grace or
     requirement of notice provided under this Agreement).


                                  ARTICLE IX

                            SUPPLEMENTAL AGREEMENTS

 
                                      45


          Section 9.01.  Supplemental Agreements Without Consent of
                         ------------------------------------------
     Certificateholders.  Without the consent of the Certificateholders of any
     ------------------                                                       
     series, the Company may, and the  Trustee (subject to Section 9.03) shall,
     at any time and from time to time, enter into one or more agreements
     supplemental hereto, in form satisfactory to the Trustee, for any of the
     following purposes:

          (1) to provide for the formation of a Trust, the issuance of a series
     of Certificates and the other matters contemplated by Section 2.01(b); or

          (2) to evidence the succession of another corporation to the Company
     and the assumption by any such successor of the covenants of the Company
     herein contained; or

          (3) to add to the covenants of the Company for the benefit of the
     Certificateholders of any series, or to surrender any right or power in
     this Agreement conferred upon the Company; or

          (4) to correct or supplement any provision in this Agreement which may
     be defective or inconsistent with any other provision herein or in any
     Trust Supplement or to modify any other provision with respect to matters
     or questions arising under this Agreement, provided that any such action
                                                --------                     
     shall not adversely affect the interests of the Certificateholders of any
     series; or to cure any ambiguity or correct any mistake; or

          (5) to modify, eliminate or add to the provisions of this Agreement to
     such extent as shall be necessary to continue the qualification of this
     Agreement (including any supplemental agreement) under the Trust Indenture
     Act or under any similar Federal statute hereafter enacted, and to add to
     this Agreement such other provisions as may be expressly permitted by the
     Trust Indenture Act, excluding, however, the provisions referred to in
     Section 316(a)(2) of the Trust Indenture Act as in effect at the date as of
     which this instrument was executed or any corresponding provision in any
     similar Federal statute hereafter enacted; or

          (6) to evidence and provide for the acceptance of appointment under
     this Agreement by the Trustee or a successor Trustee with respect to one or
     more Trusts and to add to or change any of the provisions of this Agreement
     as shall be necessary to provide for or facilitate the administration of
     the Trusts hereunder and thereunder by more than one Trustee, pursuant to
     the requirements of Section 7.09; or

          (7) to provide the information required under Section 7.11 and Section
     12.03 as to the Trustee; or

 
                                      46


          (8) to make any other amendments or modifications hereto, provided 
                                                                    --------
such amendments or modifications shall only apply to Certificates of one or more
series to be thereafter issued.

          Section 9.02.  Supplemental Agreements with Consent of
                         ---------------------------------------
Certificateholders.  With respect to each separate Trust and the series of
- ------------------                                                        
Certificates relating thereto, with the consent of the Certificateholders
holding Certificates evidencing Fractional Undivided Interests aggregating not
less than a majority in interest in such Trust, by Act of said
Certificateholders delivered to the Company and the Trustee, the Company may
(with the consent of the Owner  Trustee, if any, relating to such Certificates,
which consent shall not be unreasonably withheld), and the Trustee (subject to
Section 9.03) shall, enter into an agreement or agreements supplemental hereto
for the purpose of adding any provisions to or changing in any manner or
eliminating any of the provisions of this Agreement to the extent applicable to
such Certificateholders or of modifying in any manner the rights and obligations
of such Certificateholders under this Agreement; provided, however, that no such
                                                 --------  -------              
supplemental agreement shall, without the consent of the Certificateholder of
each Outstanding Certificate affected thereby:

          (1) reduce in any manner the amount of, or delay the timing of, any
     receipt by the Trustee of payments on the Equipment Notes held in such
     Trust or distributions that are required to be made herein on any
     Certificate of such series, or change any date of payment on any
     Certificate of such series, or change the place of payment where, or the
     coin or currency in which, any Certificate of such series is payable, or
     impair the right to institute suit for the enforcement of any such payment
     or distribution on or after the Regular Distribution Date or Special
     Distribution Date applicable thereto; or

          (2) permit the disposition of any Equipment Note in the Trust Property
     of such Trust except as permitted by this Agreement, or otherwise deprive
     such Certificateholder of the benefit of the ownership of the Equipment
     Notes in such Trust; or

          (3) reduce the percentage of the aggregate Fractional Undivided
     Interests of such Trust which is required for any such supplemental
     agreement, or reduce such percentage required for any waiver (of compliance
     with certain provisions of this Agreement or certain defaults hereunder and
     their consequences) provided for in this Agreement; or

          (4) modify any of the provisions of this Section or Section 6.05,
     except to increase any such percentage or to provide that certain other
     provisions of this Agreement cannot be modified or waived without the
     consent of the Certificateholder of each Certificate of such series
     affected thereby.

 
                                      47


          It shall not be necessary for any Act of such Certificateholders under
this Section to approve the particular form of any proposed supplemental
agreement, but it shall be sufficient if such Act shall approve the substance
thereof.

          Section 9.03.  Documents Affecting Immunity or Indemnity.  If in the
                         -----------------------------------------            
opinion of the Trustee any document required to be executed by it pursuant to
the terms of Section 9.01 or 9.02 affects any interest, right, duty, immunity or
indemnity in favor of the Trustee under this Basic Agreement or any Trust
Supplement, the Trustee may in its discretion decline to execute such document.

          Section 9.04.  Execution of Supplemental Agreements.  In executing, or
                         ------------------------------------                   
accepting the additional trusts created by, any supplemental agreement permitted
by this Article or the modifications thereby of the trusts created by this
Agreement, the Trustee shall be entitled to receive, and shall be fully
protected in relying upon, an Opinion of Counsel stating that the execution of
such supplemental agreement is authorized or permitted by this Agreement.

          Section 9.05.  Effect of Supplemental Agreements.  Upon the execution
                         ---------------------------------                     
of any supplemental agreement under this Article, this Basic Agreement shall be
modified in accordance therewith, and such supplemental agreement shall form a
part of this Basic Agreement for all purposes; and every Certificateholder of
each series theretofore or thereafter authenticated and delivered hereunder
shall be bound thereby to the extent applicable to such series.

          Section 9.06.  Conformity with Trust Indenture Act.  Every
                         -----------------------------------        
supplemental agreement executed pursuant to this Article shall conform to the
requirements of the Trust Indenture Act as then in effect.

          Section 9.07.  Reference in Certificates to Supplemental Agreements.
                         ----------------------------------------------------  
Certificates of each series authenticated and delivered after the execution of
any supplemental agreement applicable to such series pursuant to this Article
may bear a notation in form approved by the Trustee as to any matter provided
for in such supplemental agreement; and, in such case, suitable notation may be
made upon Outstanding Certificates of such series after proper presentation and
demand.

 
                                      48


                                   ARTICLE X

                  AMENDMENTS TO INDENTURE AND NOTE DOCUMENTS

          Section 10.01.  Amendments and Supplements to Indenture and Other Note
                          ------------------------------------------------------
Documents.  In the event that the Trustee, as holder of any Equipment Notes in
- ---------                                                                     
trust for the benefit of the Certificateholders of any series, receives a
request for a consent to any amendment, modification, waiver or supplement under
any related Indenture or other related Note Document or any related Note
Purchase Agreement, the Trustee shall forthwith send a notice of such proposed
amendment, modification, waiver or supplement to each Certificateholder of such
series registered on the Register as of such date.  The Trustee shall request
from the Certificateholders of such series a direction as to (i) whether or not
to direct the Trustee to take or refrain from taking any action which a holder
of such Equipment Note has the option to direct, (ii) whether or not to give or
execute any waivers, consents, amendments, modifications or supplements as a
holder of such Equipment Note and (iii) how to vote the Equipment Notes if a
vote has been called for with respect thereto.  Provided such a request for
Certificateholder Direction shall have been made, in directing any action or
casting any vote or giving any consent as the holder of any such Equipment
Notes, the Trustee shall vote or consent with respect to such Equipment Note in
the same proportion as the Certificates of such series were actually voted by
Acts of Certificateholders delivered to the Trustee prior to two Business Days
before the Trustee directs such action or casts such vote or gives such consent.
Notwithstanding the foregoing, but subject to Section 6.04, in the case that an
Event of Default hereunder with respect to such series shall have occurred and
be continuing, the Trustee may, in its own discretion and at its own direction,
consent and notify the relevant Loan Trustee of such consent to any amendment,
modification, waiver or  supplement under the relevant Indenture or any other
related Note Document.


                                  ARTICLE XI

                             TERMINATION OF TRUSTS

          Section 11.01.  Termination of the Trusts.  In respect of each Trust
                          -------------------------                           
created by the Basic Agreement as supplemented by a related Trust Supplement,
the respective obligations and responsibilities of the Company and the Trustee
created under this Agreement and the Trust created hereby and such Trust shall
terminate upon the distribution to all Holders of the Certificates of the series
of such Trust and the Trustee of all amounts required to be distributed to them
pursuant to this Agreement and the disposition of all property held as part of
the Trust Property of the related series of such Trust; provided, however, that
                                                        --------  -------      
in no event shall such Trust continue beyond the final expiration date
determined as provided in this Agreement.

 
                                      49


          Notice of any termination of a Trust, specifying the applicable
Regular Distribution Date (or applicable Special Distribution Date, as the case
may be) upon which the Certificateholders of any series may surrender their
Certificates to the Trustee for payment of the final distribution and
cancellation, shall be mailed promptly by the Trustee to Certificateholders of
such series not earlier than the minimum number of days and not more than the
maximum number of days specified therefor in the related Trust Supplement
preceding such final distribution specifying (A) the Regular Distribution Date
(or Special Distribution Date, as the case may be) upon which the proposed final
payment of the Certificates of such series will be made upon presentation and
surrender of Certificates of such series at the office or agency of the Trustee
therein specified (B) the amount of any such proposed final payment, and (C)
that the Record Date otherwise applicable to such Regular Distribution Date (or
Special Distribution Date, as the case may be) is not applicable, payments being
made only upon presentation and surrender of the Certificates of such series at
the office or agency of the Trustee therein specified.  The Trustee shall give
such notice to the Registrar at the time such notice is given to
Certificateholders of such series.  Upon presentation and surrender of the
Certificates of such series, the Trustee shall cause to be distributed to
Certificateholders of such series amounts distributable on such Regular
Distribution Date (or Special Distribution Date, as the case may be) pursuant to
Section 4.02.

          In the event that all of the Certificateholders of such series shall
not surrender their Certificates for cancellation within six months after the
date specified in the above-mentioned written notice, the Trustee shall give a
second written notice to the remaining Certificateholders of such series to
surrender their Certificates for cancellation and receive the final distribution
with respect thereto.  In the event that any money held by the Trustee for the
payment of distributions on the Certificates of such series shall remain
unclaimed for two years (or such lesser time as the Trustee shall be satisfied,
after sixty days' notice from the Company, is one month prior to the escheat
period provided under applicable law) after the final distribution date with
respect thereto, the Trustee shall pay to each Loan Trustee the appropriate
amount of money relating to such Loan Trustee and shall give written notice
thereof to the related Owner Trustees and the Company.


                                  ARTICLE XII

                           MISCELLANEOUS PROVISIONS

          Section 12.01.  Limitation on Rights of Certificateholders.  The death
                          ------------------------------------------            
or incapacity of any Certificateholder of any series shall not operate to
terminate this Agreement or the related Trust, nor entitle such
Certificateholder's legal representatives or heirs to claim an accounting or to
take any action or commence any proceeding in any court for a partition

 
                                      50


or winding up of the Trust, nor otherwise affect the rights, obligations, and
liabilities of the parties hereto or any of them.

          Section 12.02.  Certificates Nonassessable and Fully Paid.
                          -----------------------------------------  
Certificateholders of each series shall not be personally liable for obligations
of the related Trust, the Fractional Undivided Interests represented by the
Certificates of such series shall be nonassessable for any losses or expenses of
such Trust or for any reason whatsoever, and Certificates of such series upon
authentication thereof by the Trustee pursuant to Section 3.02 are and shall be
deemed fully paid.  No Certificateholder of such series shall have any right
(except as expressly provided herein) to vote or in any manner  otherwise
control the operation and management of the related Trust Property, the related
Trust, or the obligations of the parties hereto, nor shall anything set forth
herein, or contained in the terms of the Certificates of such series, be
construed so as to constitute the Certificateholders of such series from time to
time as partners or members of an association.

          Section 12.03.  Notices.  (a)  Unless otherwise specifically provided
                          -------                                              
herein or the applicable Trust Supplement with respect to any Trust, all notices
required under the terms and provisions of this Basic Agreement or such Trust
supplement with respect to such Trust shall be in English and in writing, and
any such notice may be given by United States mail, courier service or telecopy,
and any such notice shall be effective when delivered or received or, if mailed,
three days after deposit in the United States mail with proper postage for
ordinary mail prepaid,

          if to the Company, to:

               United Air Lines, Inc.
               P.O. Box 66100
               Chicago, Illinois 60666
               Attention:  Vice President and Treasurer
               Facsimile:  (708) 952-7117

          or if by overnight courier, to:

               United Air Lines, Inc.
               1200 East Algonquin Road
               Elk Grove Township, Illinois  60007
               Attention:  Vice President and Treasurer

          if to State Street Bank and Trust Company of Connecticut, National
Association, as Trustee, to:

 
                                      51

               c/o State Street Bank and Trust Company of Connecticut,
                National Association
               225 Franklin Street IP-4
               Boston, Massachusetts 02110
               Attention:  Corporate Trust Department
               Facsimile:  (203) 244-1899
               Telephone:  (203) 244-1800

          as to any series of Certificates, as specified in the Trust Supplement
related thereto.

          (b) The Company or the Trustee as to any series of Certificates, by
notice to the other, may designate additional or different addresses for
subsequent notices or communications.

          (c) Any notice or communication to Certificateholders of any series
shall be mailed by first-class mail to the addresses for Certificateholders of
such series shown on the Register kept by the Registrar and to addresses filed
with the Trustee for Certificate Owners of such series.  Failure so to mail a
notice or communication or any defect in such notice or communication shall not
affect its sufficiency with respect to other Certificateholders of such series.

          (d) If a notice or communication is mailed in the manner provided
above within the time prescribed, it is conclusively presumed to have been duly
given, whether or not the addressee receives it.

          (e) If the Company mails a notice or communication to the
Certificateholders of such series, it shall mail a copy to the Trustee and to
each Paying Agent for such series at the same time.

          (f) Notwithstanding the foregoing, all communications or notices to
the Trustee shall be deemed to be given only when received by a Responsible
Officer of the Trustee.

          (g) The Trustee shall promptly furnish the Company with a copy of any
demand, notice or written communication received by the Trustee hereunder from
any Certificateholder, Owner Trustee or Loan Trustee.

          Section 12.04.  Governing Law.  THIS BASIC AGREEMENT HAS BEEN
                          -------------                                
DELIVERED IN THE STATE OF NEW YORK AND THE CERTIFICATES SHALL BE CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK

 
                                      52


AND THE OBLIGATIONS, RIGHTS, AND REMEDIES OF THE PARTIES HEREUNDER SHALL BE
DETERMINED IN ACCORDANCE WITH SUCH LAWS.

          Section 12.05.  Severability of Provisions.  If any one or more of the
                          --------------------------                            
covenants, agreements, provisions or terms of this Agreement shall be for any
reason whatsoever held invalid, then such covenants, agreements, provisions, or
terms shall be deemed severable from the remaining covenants, agreements,
provisions or terms of this Agreement and shall in no way affect the validity or
enforceability of the other provisions of this Agreement or any Trust, or of the
Certificates of any series or the rights of the Certificateholders thereof.

          Section 12.06.  Trust Indenture Act Controls.  This Agreement is
                          ----------------------------                    
subject to the provisions of the Trust Indenture Act and shall, to the extent
applicable, be governed by such provisions.

          Section 12.07.  Effect of Headings and Table of Contents.  The Article
                          ----------------------------------------              
and Section headings herein and the Table of Contents are for convenience only
and shall not affect the construction hereof.

          Section 12.08.  Successors and Assigns.  All covenants, agreements,
                          ----------------------                             
representations and warranties in this Agreement by the Trustee and the Company
shall bind and, to the extent permitted hereby, shall inure to the benefit of
and be enforceable by their respective successors and assigns, whether so
expressed or not.

          Section 12.09.  Benefits of Agreement.  Nothing in this Agreement or
                          ---------------------                               
in the Certificates of any series, express or implied, shall give to any Person,
other than the parties hereto and their successors hereunder, and the
Certificateholders of each series, any benefit or any legal or equitable right,
remedy or claim under this Agreement.

          Section 12.10.  Legal Holidays.  In any case where any Regular
                          --------------                                
Distribution Date or Special Distribution Date relating to any Certificate of
any series shall not be a Business Day with respect to such series, then
(notwithstanding any other provision of this Agreement) payment need not be made
on such date, but may be made on the next succeeding Business Day with the same
force and effect as if made on such Regular Distribution Date or Special
Distribution Date, and no interest shall accrue during the intervening period.

          Section 12.12.  Counterparts.  For the purpose of facilitating the
                          ------------                                      
execution of this Agreement and for other purposes, this Agreement may be
executed simultaneously in any number of counterparts, each of which
counterparts shall be deemed to be an original, and all of which counterparts
shall constitute but one and the same instrument.

 
                                      53


          IN WITNESS WHEREOF, the parties have caused this amended and restated
Basic Agreement to be duly executed by their respective officers.


                                             UNITED AIR LINES, INC.



                                             By ___________________________
                                                Name:
                                                Title:



                                             STATE STREET BANK AND TRUST
                                                COMPANY OF CONNECTICUT,
                                                NATIONAL ASSOCIATION, as
                                                Trustee



                                             By
                                                ___________________________
                                                Name:
                                                Title:

 

 
                                                                       EXHIBIT A


                              FORM OF CERTIFICATE

          Unless this certificate is presented by an authorized representative
     of The Depository Trust Company, a New York Corporation ("DTC") to Issuer
     or its agent for registration of transfer, exchange or payment, and any
     certificate issued is registered in the name of Cede & Co. or in such other
     name as is requested by an authorized representative of DTC (and any
     payment is made to Cede & Co. or to such other entity as is requested by an
     authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF
     FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch the
     registered owner hereof, Cede & Co., has an est herein.



                  UNITED AIR LINES _______ PASS THROUGH TRUST

                                  Pass Through
                          Certificate, Series _______

                   Final Distribution Date:  __________, ____

evidencing a fractional undivided interest in a trust, the property of which
includes certain equipment notes each secured by an Aircraft owned by or leased
to United Air Lines, Inc.

Certificate
No. _______         $____________ Fractional Undivided Interest
                    representing .________% of the Trust per $1,000 face amount

          THIS CERTIFIES THAT ______________________, for value received, is the
registered owner of a $____________ (________________ dollars) Fractional
Undivided Interest in the United Air Lines _______ Pass Through Trust (the
"Trust") created pursuant to a Pass Through Trust Agreement, dated as of
February 1, 1992, as amended and restated as of May 1, 1995 (the "Basic
Agreement"), as supplemented by Trust Supplement No. ___________________
thereto, dated ________, 199_  (collectively, the "Agreement"), between
___________ (the "Trustee") and United Air Lines, Inc., a corporation
incorporated under Delaware law (the "Company"), a summary of certain of the
pertinent provisions of which is set forth below.  To the extent not otherwise
defined herein, the capitalized terms used herein have the meanings assigned to
them in the Agreement.  This Certificate is one of the duly authorized
Certificates designated as "Pass Through Certificates, Series _______" (herein
called the _______________________.


     * This legend to appear on Book-Entry Certificates to be deposited with 
       the Depository Trust Company.  One Certificate may be issued in a 
       denomination of less than $1,000 which shall not have this legend.      

 
                                      A-2

"Certificates").  This Certificate is issued under and is subject to the terms,
provisions, and conditions of the Agreement, to which Agreement the
Certificateholder of this Certificate by virtue of the acceptance hereof assents
and by which such Certificateholder is bound.  The property of the Trust
includes certain Equipment Notes (the "Trust Property").  Each issue of the
Equipment Notes is secured by a security interest in an aircraft leased to or
owned by the Company.

          The Certificates represent fractional undivided interests in the Trust
and the Trust Property, and have no rights, benefits or interest in respect of
any other separate trust established pursuant to the terms of the Basic
Agreement for any other series of certificates issued pursuant thereto.

          Subject to and in accordance with the terms of the Agreement, from
funds then available to the Trustee, there will be distributed on each ________
and ____________ (a "Regular Distribution Date"), commencing on ________, 199_,
to the Person in whose name this Certificate is registered at the close of
business on the 15th day preceding the Regular Distribution Date, an amount in
respect of the Scheduled Payments on the Equipment Notes due on such Regular
Distribution Date, the receipt of which has been confirmed by the Trustee, equal
to the product of the percentage interest in the Trust evidenced by this
Certificate and an amount equal to the sum of such Scheduled Payments.  Subject
to and in accordance with the terms of the Agreement, in the event that Special
Payments on the Equipment Notes are received by the Trustee, from funds then
available to the Trustee, there shall be distributed on the applicable Special
Distribution Date, to the Person in whose name this Certificate is registered at
the close of business on the 15th day preceding the Special Distribution Date,
an amount in respect of such Special Payments on the Equipment Notes, the
receipt of which has been confirmed by the Trustee, equal to the product of the
percentage interest in the Trust evidenced by this Certificate and an amount
equal to the sum of such Special Payments so received.  If a Regular
Distribution Date or Special Distribution Date is not a Business Day,
distribution shall be made on the immediately following Business Day with the
same force and effect as if made on such Regular Distribution Date or Special
Distribution Date and no interest shall accrue during the intervening period.
The Special Distribution Date, shall be the _____________ day of the month
determined as provided in the Agreement.  The Trustee shall mail notice of each
Special Payment and the Special Distribution Date therefor to the
Certificateholder of this Certificate.

          Distributions on this Certificate will be made by the Trustee by check
mailed to the Person entitled thereto, without the presentation or surrender of
this Certificate or the making of any notation hereon.  Except as otherwise
provided in the Agreement and notwithstanding the above, the final distribution
on this Certificate will be made after notice mailed by the Trustee of the
pendency of such distribution and only upon presentation and surrender of this
Certificate at the office or agency of the Trustee specified in such notice.

 
                                      A-3


          THE AGREEMENT AND THIS CERTIFICATE SHALL BE GOVERNED BY AND CONSTRUED
IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK WITHOUT GIVING EFFECT TO
THE CONFLICT OF LAWS PROVISIONS OF THE STATE OF NEW YORK.

          Reference is hereby made to the further provisions of this Certificate
set forth in the reverse hereof, which further provisions shall for all purposes
have the same effect as if set forth at this place.

          Unless the certificate of authentication hereon has been executed by
the Trustee, by manual signature, this Certificate shall not be entitled to any
benefit under the Agreement or be valid for any purpose.

          IN WITNESS WHEREOF, the Trustee has caused this Certificate to be duly
executed.


                                    UNITED AIR LINES
                                     PASS THROUGH TRUST



                                    By: _______________________, as
                                        Trustee


                                      By:  _______________________
                                        Title:
Dated:

 
                                      A-4

             [FORM OF THE TRUSTEE'S CERTIFICATE OF AUTHENTICATION]


                    This is one of the Certificates referred
                    to in the within-mentioned Agreement.



                                    ___________________________, as
                                        Trustee


                                      By:  _______________________
                                               Authorized Officer

 
                           [Reverse of Certificate]


          The Certificates do not represent a direct obligation of, or an
obligation guaranteed by, or an interest in, the Company or the Trustee or any
affiliate thereof.  The Certificates are limited in right or payment, all as
more specifically set forth on the face hereof and in the Agreement.  All
payments or distributions made to Certificateholders under the Agreement shall
be made only from the Trust Property and only to the extent that the Trustee
shall have sufficient income or proceeds from the Trust Property to make such
payments in accordance with the terms of the Agreement.  Each Certificateholder
of this Certificate, by its acceptance hereof, agrees that it will look solely
to the income and proceeds from the Trust Property to the extent available for
distribution to such Certificateholder as provided in the Agreement.  This
Certificate does not purport to summarize the Agreement and reference is made to
the Agreement for information with respect to the interests, rights, benefits,
obligations, proceeds, and duties evidenced hereby.  A copy of the Agreement may
be examined during normal business hours at the principal office of the Trustee,
and at such other places, if any, designated by the Trustee, by any
Certificateholder upon request.

          The Agreement permits, with certain exceptions therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Certificateholders under the Agreement at any time
by the Company and the Trustee with the consent of the Certificateholders
holding Certificates evidencing Fractional Undivided Interests aggregating not
less than a majority in interest in the Trust.  Any such consent by the
Certificateholder of this Certificate shall be conclusive and binding on such
Certificateholder and upon all future Certificateholders of this Certificate and
of any Certificate issued upon the transfer hereof or in exchange hereof or in
lieu hereof whether or not notation of such consent is made upon this
Certificate.  The Agreement also permits the amendment thereof, in certain
limited circumstances, without the consent of the Certificateholders of any of
the Certificates.

          As provided in the Agreement and subject to certain limitations
therein set forth, the transfer of this Certificate is registrable in the
Register upon surrender of this Certificate for registration of transfer at the
offices or agencies maintained by the Trustee in its capacity as Registrar, or
by any successor Registrar, in the Borough of Manhattan, the City of New York,
duly endorsed or accompanied by a written instrument of transfer in form
satisfactory to the Trustee and the Registrar duly executed by the
Certificateholder hereof or such Certificateholder's attorney duly authorized in
writing, and thereupon one or more new Certificates of authorized denominations
evidencing the same aggregate Fractional Undivided Interest in the Trust will be
issued to the designated transferee or transferees.

          The Certificates are issuable only as registered Certificates without
coupons in minimum denominations of $1,000 Fractional Undivided Interest and
integral multiples thereof except that one Certificate may be in a denomination
of less than $1,000.  As

 
                                       2

provided in the Agreement and subject to certain limitations therein set forth,
the Certificates are exchangeable for new Certificates of authorized
denominations evidencing the same aggregate Fractional Undivided Interest in the
Trust, as requested by the Certificateholder surrendering the same.

          No service charge will be made for any such registration of transfer
or exchange, but the Trustee shall require payment of a sum sufficient to cover
any tax or governmental charge payable in connection therewith.

          The Trustee, the Registrar, and any agent of the Trustee or the
Registrar may treat the person in whose name this Certificate is registered as
the owner hereof for all purposes, and neither the Trustee, the Registrar, nor
any such agent shall be affected by any notice to the contrary.

          The obligations and responsibilities created by the Agreement and the
Trust created thereby shall terminate upon the distribution to
Certificateholders of all amounts required to be distributed to them pursuant to
the Agreement and the disposition of all property held as part of the Trust
Property.