Exhibit 10.10
                  
                  Supplemental Agreement No. 5    

                               to

                   Purchase Agreement No. 1663

                             between

                       The Boeing Company

                               and
                                
                     UNITED AIR LINES, INC.
                                
            Relating to Boeing Model 777-222 Aircraft
                                
      THIS SUPPLEMENTAL AGREEMENT, entered into as of the 12 day
of July, 1996, by and between THE BOEING COMPANY, a Delaware
corporation (hereinafter called Boeing), and UNITED AIR LINES,
INC., a Delaware corporation, (hereinafter called Buyer);


                      W I T N E S S E T H:
                      -------------------

     WHEREAS, the parties hereto entered into an agreement dated
as of December 18, 1990, relating to Boeing Model 777-222
aircraft (hereinafter referred to as the "Aircraft"), which
agreement, as amended, together with all exhibits and
specifications attached thereto and made a part thereof which is
hereinafter called the "Purchase Agreement" and;

[*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE
SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR
CONFIDENTIAL TREATMENT]

     NOW THEREFORE, in consideration of the mutual covenants
herein contained, the parties hereto agree to supplement the
Purchase Agreement as follows:

1.  Article 3, "Basic Price", is hereby deleted in its entirety
and replaced with a new Article 3 which is Attachment No. 1
hereto.


P.A. No. 1663                  S5-1



2.  Article 5, "Payment", is hereby deleted in its entirety and
replaced with a new Article 5 which is Attachment No. 2 hereto.

3.  Paragraph 6 of Letter Agreement No. 6-1162-RCN-859 provides that
the [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE
SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR
CONFIDENTIAL TREATMENT] given below.  The calculations are based
on a July 15, 1996 settlement date.

[*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE
SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR
CONFIDENTIAL TREATMENT]

4.  Model 777 Aircraft - Certain Contractual Matters.
    ------------------------------------------------

[*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE
SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR
CONFIDENTIAL TREATMENT]

5.  This Supplemental Agreement, including all of the
Attachments, will be treated as privileged and confidential
information pursuant to the terms of Letter Agreement No. 6-1162-
DLJ-832.

The Purchase Agreement shall be deemed to be supplemented to the
extent herein provided and as so supplemented shall continue in
full force and effect.

EXECUTED IN DUPLICATE as of the day and year first above written.

THE BOEING COMPANY                      UNITED AIR LINES, INC.

By: /s/ M. O. Hurt                 By: /s/ Douglas A. Hacker
    --------------                     ---------------------

Its: Attorney-In-Fact              Its: Senior Vice President and
                                        Chief Financial Officer



P.A. No. 1663               S5-2



Attachment No. 1 to
Supplemental Agreement No. 5
Purchase Agreement No. 1663


Article 3.  Price of Aircraft.
            -----------------

      3.1  Basic Price.
     
           3.1.1     Basic Price for the "A" Market Aircraft.  The
basic price of each of the "A" Market Aircraft shall be equal to
the sum of [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY
WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST
FOR CONFIDENTIAL TREATMENT] and (ii) such price adjustments
applicable to such "A" Market Aircraft as may be made pursuant to
the provisions of this Agreement, including Article 7 (Changes to
Detail Specification) and Article 8 (FAA Requirements') or other
written agreements executed by Buyer and Boeing.
     
           3.1.2     Basic Price for the Block A "B" Market
Aircraft.  The basic price of each of the Block A "B" Market
Aircraft shall be equal to the sum of (i) the price of the
airframe and special features, [*CONFIDENTIAL MATERIAL OMITTED
AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT] and (ii) such
price adjustments applicable to such Block A "B" Market Aircraft
as may be made pursuant to the provisions of this Agreement,
including Article 7 (Changes to Detail Specification) and Article
8 (FAA Requirements) or other written agreements executed by
Buyer and Boeing.

           3.1.3     Basic Price for the Block B "B" Market
Aircraft.  The basic price of each of the Block B "B" Market
Aircraft shall be equal to the sum of (i) the price of the
airframe and special features, [*CONFIDENTIAL MATERIAL OMITTED
AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT] and (ii) such
price adjustments applicable to such Block B "B" Market Aircraft
as may be made pursuant to the provisions of this Agreement,
including Article 7 (Changes to Detail Specification) and Article
8 (FAA Requirements) or other written agreements executed by
Buyer and Boeing.

      3.2  Purchase Price.
           --------------
          The purchase price of each Aircraft shall be equal to
the sum of the following items as determined at the time of such
Aircraft delivery; (i) the Basic Price of the "A" Market
Aircraft, Block A "B" Market Aircraft, or Block B "B" Market
Aircraft as applicable, (ii) the Airframe and Engine Price
Adjustments to be determined pursuant to Exhibit D (Price
Adjustment Due to Economic Fluctuations - Airframe and Engine)
attached hereto or the applicable provisions determined in
Article 3.1 above, and (iii) such price adjustments applicable to
such Aircraft as may be made pursuant to the provisions of this
Agreement, including Exhibit E (Buyer Furnished Equipment
Document) or other written agreements executed by Boeing and
Buyer (the "Purchase Price").


Attachment No. 2 to
Supplemental Agreement No. 5
Purchase Agreement No. 1663


ARTICLE 5.  Payment.
            -------

      5.1  Advance Payment Base Price.  The advance payment base
price of each Aircraft, depending on the month and year of
scheduled delivery, is indicated below:

Month and Year of          Advance Payment Base
Scheduled Delivery         Price per Aircraft
- ------------------         ------------------

"A" Market Aircraft
- -------------------

May 1995                   [*CONFIDENTIAL MATERIAL OMITTED
June 1995                  AND FILED SEPARATELY WITH
July 1995                  THE SECURITIES AND EXCHANGE
September 1995             COMMISSION PURSUANT TO A
October 1995               REQUEST FOR CONFIDENTIAL
November 1995              TREATMENT]
December 1995
February 1996
April 1996
May 1996
June 1996
July 1996

"B" Market Aircraft
- -------------------

Block A "B" Market Aircraft
- ---------------------------

[*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE
SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR
CONFIDENTIAL TREATMENT]

Such advance payment base prices will be used to determine the
amount of the first advance payment to be made by Buyer on each
Aircraft pursuant to the provisions of Article 5.2.  The advance
payment base price of each Aircraft has been established using
currently available forecast of the escalation factors used by
Boeing and applicable to the scheduled month and year of Aircraft
delivery.  The advance payment base prices will be further
increased or decreased by Boeing not later than twenty-five (25)
months prior to the scheduled month of delivery, as required to
reflect the effects of the then-current forecasted escalation
factors used by Boeing in accordance with Exhibit D. The advance
payment base price of each Aircraft, including any adjustments
made thereto, as contemplated herein, is referred to as the
"Advance Payment Base Price."

      5.2  Advance Payments.  Buyer shall pay to Boeing advance
payments for each Aircraft on the dates indicated in the schedule
below.  The advance payment amount for an Aircraft due on a
payment date shall be equal to (i) the sum of the advance payment
percentages given in such schedule through the payment date
multiplied by the Advance Payment Base Price for the Aircraft
provided to Buyer pursuant to Article 5.1 for such payment date,
less (ii) the sum of the advance payment amounts paid by Buyer to
Boeing on such Aircraft up to such payment date.

Attachment No. 2 to
Supplemental Agreement No. 5
Purchase Agreement No. 1663


     Due Date of Payment                 Amount Due per Aircraft
     -------------------                 -----------------------

     Upon execution of a definitive
     purchase agreement

     24 months prior to the first
     day of the scheduled delivery
     month of the Aircraft

     21 months prior to the first
     day of the scheduled delivery
     month of the Aircraft
                                        [*CONFIDENTIAL MATERIAL
     18 months prior to the first       OMITTED AND FILED
     day of the scheduled delivery      SEPARATELY WITH
     month of the Aircraft              THE SECURITIES AND
                                        EXCHANGE COMMISSION
     15 months prior to the first       PURSUANT TO A REQUEST
     day of the scheduled delivery      FOR CONFIDENTIAL
     month of the Aircraft              TREATMENT]

     12 months prior to the first
     day of the scheduled delivery
     month of the Aircraft

     9 months prior to the first
     day of the scheduled delivery
     month of the Aircraft

     6 months prior to the first
     day of the scheduled delivery
     month of the Aircraft
     
     [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH
     THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST
     FOR CONFIDENTIAL TREATMENT]
     
     5.3  Payment for Aircraft.  Concurrently with delivery of
each Aircraft, Buyer shall pay to Boeing the Purchase Price
thereof, less the total amount of advance payments theretofore
received by Boeing for such Aircraft under Article 5.2.

     5.4  Repayment of Advance Payments.  If this Agreement is
terminated with respect to any Aircraft (i) by Buyer under
Article 6.2, (ii) by Buyer under Article 11, or (iii) by failure
of Buyer to provide Boeing with written notice pursuant to
Article 6.4, then Boeing shall promptly repay to Buyer, without
interest, any advance payments received by Boeing from Buyer here
under with respect to any Aircraft so terminated.  If this
Agreement is terminated by Boeing under Article 6.2, then Boeing
shall promptly repay to Buyer with interest any advance payments
received by Boeing from Buyer hereunder with respect to any
Aircraft so terminated.

     5.5  Payment in United States Funds.  All prices and
payments set forth in this Agreement are in United States
Dollars.  All payments required under this Agreement shall be
made in United States Dollars and in immediately available funds
by (i) transfer to the party to receive payment of a cashier's
check drawn on a member bank, located at Seattle, Washington, of
the United States Federal Reserve System mutually acceptable to
the parties, or (ii) unconditional deposit to the account of the
party to receive payment in a bank in the United States mutually
acceptable to the parties.  Buyer shall comply with all
applicable monetary and exchange control regulations, and shall
obtain any necessary authority from the governmental agency
administering such regulations in order to enable Buyer to make
payments at the time and place and in the manner and medium
specified herein.


Supplemental Agreement No. 5
Purchase Agreement No. 1663




[*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND
EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]