Exhibit 10.39
                                                      -------------
                                                      
                  Supplemental Agreement No. 7
                                
                               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 6th day
of November, 1998, 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;

     WHEREAS, Buyer wishes to purchase an additional ten (10)
Model 777-222 "B" market aircraft and six (6) Model 777-222 "A"
Market aircraft pursuant to Letter Agreement No. 6-1162-MDH-770;

     WHEREAS, Boeing wishes to restate the Specification for the
Model 777-222 "A" Market Aircraft in its new DCAC system of
stating and controlling aircraft specifications, as opposed to
its old Legacy system;

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


P.A. No. 1663               S7-1                        SA7


Supplemental Agreement No. 7
Purchase Agreement No. 1663


1.     In the TABLE OF CONTENTS the title of EXHIBIT D is revised
to read:

           "Price Adjustment Due to Economic
           Fluctuations - Airframe and Engine
           Block A "A" Market Aircraft, Block A "B" Market
           Aircraft and Block B "B" Market Aircraft"

2.     In the TABLE OF CONTENTS following EXHIBIT D Price
Adjustment Due to Economic Fluctuations - Airframe and Engine
Block A "A" Market Aircraft, Block A "B" Market Aircraft and
Block B "B" Market Aircraft add the following:

"EXHIBIT D-1     "Price Adjustment Due to Economic
                 Fluctuations - Airframe and Engine
                 Block B "A" Market Aircraft and
                 Block C "B" Market Aircraft"

3.     Article 1.1.1 is revised as follows:

       (a)     in the first sentence, the words, "twenty-two
              (22)" are inserted in lieu of the words "sixteen
              (16)";

       (b)     in the second sentence, after the words
               "collectively as" insert the words "Block A
               "A" Market Aircraft and Block B "A" Market
               Aircraft";

       (c)     in the third sentence insert the words "Block A
               "A" Market" before the word "Aircraft";

       (d)     after the third sentence, add a new sentence,
               "The Block B "A" Market Aircraft will be
               manufactured by Boeing in accordance with
               Boeing Detail Specification [*CONFIDENTIAL
               MATERIAL OMITTED AND FILED SEPARATELY WITH THE
               SECURITIES AND EXCHANGE COMMISSION PURSUANT TO
               A REQUEST FOR CONFIDENTIAL TREATMENT], Original
               Release, dated September 15, 1998 (as modified
               and described in Exhibit A-3 attached hereto)
               as it may be modified from time to time in 
               accordance with the terms and conditions of 
               Article 7 herein.";

       (e)     at the end of what used to be the fourth
               sentence and is now the fifth sentence, add
               "the Block B "A" Market Aircraft, as the case
                may be."

4.     Article 1.1.2 is revised as follows:

       (a)     in the first sentence, the words "thirty  
               (30)" are inserted in lieu of the words 
               "twenty (20)";

               
P.A. No. 1663                 S7-2                      SA7


Supplemental Agreement No. 7
Purchase Agreement No. 1663


       (b)     in the second sentence, the words "Block C "B"
Market Aircraft" are inserted after the words "Block B "B" Market
Aircraft."

5.     In Article 2, Paragraph 2.1 Time of Delivery, the sub-
heading entitled "A" Market Aircraft" in the delivery schedule is
revised to read:

                 "A" Market Aircraft
                 Block A "A" Market Aircraft"

6.     In Article 2, Paragraph 2.1 Time of Delivery, following
the delivery schedule for the Block "A" A Market Aircraft, add
the following delivery schedule for the Block B "A" Market
Aircraft:

                 Block B "A" Market Aircraft

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

7.     In Article 2, Paragraph 2.1, Time of Delivery, following
the delivery schedule for the Block B "B" Market Aircraft, add
the following delivery schedule for the Block C "B" Market
Aircraft:

                 Block C "B" Market Aircraft

        March 1999                    One (1)
        [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY
        WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT
        TO A REQUEST FOR CONFIDENTIAL TREATMENT]

8.     Article 3.1.1 is revised as follows:

       The title is revised to read "Basic Price of the Block A
"A" Market Aircraft" and the words "Block A" are inserted before
the words "A" Market" in the first sentence.



P.A. No. 1663               S7-3                            SA7


Supplemental Agreement No. 7
Purchase Agreement No. 1663



9.     A new Paragraph 3.1.4 is added to the Purchase Agreement
which reads as follows:

            "3.1.4     Basic Price for the Block B "A" Market
Aircraft.  The basic price for each of the Block B "A" Market
Aircraft shall be equal to the sum of (i) [*CONFIDENTIAL MATERIAL
OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT] plus
the price of the engines, [*CONFIDENTIAL MATERIAL OMITTED AND
FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT] for a total of
[*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE
SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR
CONFIDENTIAL TREATMENT] (which includes the price effects of all
Change Orders through Change Order 10A) and (ii) such price
adjustments applicable to such Block B "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."

10.     A new Paragraph 3.1.5 is added to the Purchase Agreement
which reads as follows:

             "3.1.5     Basic Price for the Block C "B" Market
Aircraft.  The basic price of each of the Block C "B" Market
Aircraft shall be equal to the sum of (i) [*CONFIDENTIAL MATERIAL
OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT] for
a total of [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY
WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST
FOR CONFIDENTIAL TREATMENT] (which includes the price effects of
all Change Orders through Change Order 9A) [*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 C "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."

11.     Article 3.2 Purchase Price is revised to read:

             "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 Block A "A"
Market Aircraft, Block B "A" Market Aircraft, Block A "B" Market
Aircraft, Block B "B" Market Aircraft or Block C "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 -
Block A "A" Market Aircraft, Block A "B" Market Aircraft and
Block B "B" Market Aircraft) or Exhibit D-1 (Price Adjustment Due
to Economic Fluctuations - Airframe and Engine (Block B "A"
Market Aircraft and Block C "B" Market Aircraft) attached hereto
or the applicable provisions determined in Article 3.1 above, and
(iii) such price adjustments


P.A. No. 1663                S7-4                     SA7


Supplemental Agreement No. 7
Purchase Agreement No. 1663


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")."

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

        (a)     For future [*CONFIDENTIAL MATERIAL OMITTED AND
FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT], plus such
price adjustments applicable to such "Airframe & Special Features
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, and

        (b)     For future [*CONFIDENTIAL MATERIAL OMITTED AND
FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT], plus such
price adjustments applicable to such "Airframe & Special Features
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.

13.     In Article 5, Paragraph 5.1 Advance Payment Base Price,
the heading entitled "A" Market Aircraft" in the schedule set
forth is revised to read:

                "Block A "A" Market Aircraft"

14.     In Article 5, Paragraph 5.1, Advance Payment Base Price,
following the schedule of Advance Payment Base Prices for the
Block A "A" Market Aircraft, add the following schedule of
Advance Payment Base Prices for the Block B "A" Market Aircraft.

                "Block B "A" Market Aircraft"

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


P.A. No. 1663                 S7-5                          SA7


Supplemental Agreement No. 7
Purchase Agreement No. 1663


15.     In Article 5, Paragraph 5.1, Advance Payment Base Price,
following the schedule of Advance Payment Base Prices for the
Block B "B" Market Aircraft, add the following schedule of
Advance Payment Base Prices for the Block C "B" Market Aircraft.

                 "Block C "B" Market Aircraft"

        March 1999                            
        [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY
        WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT
        TO A REQUEST FOR CONFIDENTIAL TREATMENT]

16.     A new Exhibit A-3 is added to the Purchase Agreement,
which is attached to this Supplemental Agreement.  [*CONFIDENTIAL
MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND
EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL
TREATMENT].



P.A. No. 1663                  S7-6                     SA7


Supplemental Agreement No. 7
Purchase Agreement No. 1663


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


17.     EXHIBIT D-1 Price Adjustment Due to Economic Fluctuations
- - Airframe and Engine Block B "A" Market Aircraft and Block C "B"
Market Aircraft set forth as Attachment A hereto is added to the
Purchase Agreement.


18.     Letter Agreement 6-1162-RCN-859 entitled "Certain
Contractual Matters" is revised as follows:

        (a)     Paragraph 1.1:  The title is revised to read
"Block A "A" Market Basic Credit Memorandum - Firm Aircraft" and
the words "Block A" are inserted before the words "'A' Market" in
the first sentence;

        (b)     Paragraph 1.1.1:  The title is revised to read
"Block A and Block B "B" Market Basic Credit Memorandum - Firm
Aircraft" and the words "Block A and Block B" are inserted before
the words "'B' Market" in the first sentence;

        (c)     A new Paragraph 1.1.2 is added which reads as
follows:

                "1.1.2     Block B "A" Market Basic Credit
                           Memorandum.

                     A basic credit memorandum will be issued by
Boeing at the time of delivery of each Block B "A" Market
Aircraft in the amount of [*CONFIDENTIAL MATERIAL OMITTED AND
FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT].

        (d)     A new Paragraph 1.1.3 is added which reads as
follows:

                "1.1.3     Block C "B" Market Basic Credit
                           Memorandum.

                     A basic credit memorandum will be issued by
Boeing at the time of delivery of each Block C "B" Market
Aircraft in the amount of [*CONFIDENTIAL MATERIAL OMITTED AND
FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT].

        (e)     Paragraph 1.3:  The title is revised to Read
"Block A "A" Market Special Launch Customer Credit Memo - Firm
Aircraft" and the words "Block A" are inserted before the words
"'A' Market Aircraft" in the first sentence.


P.A. No. 1663                  S7-7                       SA7


Supplemental Agreement No. 7
Purchase Agreement No. 1663


        (f)     Paragraph 1.3.1:  The title is revised to read
"Block A and Block B "B" Market [*CONFIDENTIAL MATERIAL OMITTED
AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]" and the words
"Block A and Block B" are inserted before the words "'B' Market
Aircraft" in the first sentence.

       (g)     Paragraph 1.3.2:  The title is revised to read
"Block A and Block B "B" Market [*CONFIDENTIAL MATERIAL OMITTED
AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]" and the words
"Block A and Block B" are inserted before the words "'B'
Aircraft" in the first sentence.

       (h)     A new Paragraph 1.3.3 is added which reads as
follows:

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

       (i)     A new Paragraph 1.3.4 is added which reads as
follows:

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

       (j)     A new Paragraph 1.3.5 is added which reads as
follows:

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

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

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

19.     Letter Agreement 6-1162-DLJ-1193 entitled "Substitution
of Performance Guarantees" is revised by deleting the existing
Attachment A and substituting the revised Attachment (attached):


P.A. No. 1663                S7-8                       SA7


Supplemental Agreement No. 7
Purchase Agreement No. 1663


20.     Letter Agreement 6-1162-RCN-925 entitled "'B' Market
Aircraft Performance Guarantees" is revised by deleting the
existing Attachment A and substituting the revised Attachment
(attached).

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

22.     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.

ACCEPTED AND AGREED TO:

THE BOEING COMPANY              UNITED AIR LINES, INC.



By /s/ Brian R. Belka           By  /s/ Douglas A. Hacker
   ------------------               ---------------------
                                        Douglas A. Hacker

Its Attorney-in-Fact            Its Senior Vice President and
    ----------------                -------------------------
                                    Chief Financial Officer
                                    


P.A. No. 1663               S7-9                        SA7



                     AIRCRAFT CONFIGURATION
                                
                             between
                                
                       THE BOEING COMPANY
                                
                               and
                                
                     UNITED AIR LINES, INC.
                                
                                
                                
          Exhibit A-3 to Purchase Agreement Number 1663

                     
P.A. No. 1663              A-3                             SA7
                            i 


                           
                    AIRCRAFT CONFIGURATION
                                
                     Dated November 6, 1998
                                
                           relating to
                                
            BOEING MODEL 777-222 "A" MARKET AIRCRAFT
                                
                       Block B "A" Market


     The Detail Specification, referred to in Article 1 of the
Purchase Agreement for the Block B "A" Market Aircraft is Boeing
Detail Specification [*CONFIDENTIAL MATERIAL OMITTED AND FILED
SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT
TO A REQUEST FOR CONFIDENTIAL TREATMENT].  Such Detail
Specification will be amended to incorporate the applicable
specification language to reflect the effect of the changes set
forth in the Changes listed below, including the effects of such
changes on Manufacturer's Empty Weight (MEW) and Operating Empty
Weight (OEW).  It is understood and agreed that the Basic Price
of the Block B "A" Market Aircraft set forth in Article 3 of this
Agreement, reflects and includes all applicable price effects of
such changes.


P.A. No. 1663               A-3                         SA7
                            ii


Exhibit A-3 to
Purchase Agreement No. 1663
Page 1 of 6


DCAC
OPTION NO.                       TITLE
- ---------                        -----

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


P.A. No. 1663                                              SA7


Exhibit A-3 to
Purchase Agreement No. 1663
Page 2 of 6


DCAC
OPTION NO.                       TITLE
- ---------                        -----

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


P.A. No. 1663                                              SA7


Exhibit A-3 to
Purchase Agreement No. 1663
Page 3 of 6


DCAC
OPTION NO.                       TITLE
- ---------                        -----

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


P.A. No. 1663                                              SA7


Exhibit A-3 to
Purchase Agreement No. 1663
Page 4 of 6


DCAC
OPTION NO.                       TITLE
- ---------                        -----

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


P.A. No. 1663                                              SA7


Exhibit A-3 to
Purchase Agreement No. 1663
Page 5 of 6


DCAC
OPTION NO.                       TITLE
- ---------                        -----

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


P.A. No. 1663                                              SA7


Exhibit A-3 to
Purchase Agreement No. 1663
Page 6 of 6


DCAC
OPTION NO.                       TITLE
- ---------                        -----

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


P.A. No. 1663                                              SA7


                 AIRFRAME AND ENGINE PRICE ADJUSTMENT
                                
                             between
                                
                       THE BOEING COMPANY
                                
                               and
                                
                     UNITED AIR LINES, INC.
                                
                                
                                
   Block B "A" Market Aircraft and Block C "B" Market Aircraft
                                
          Exhibit D-1 to Purchase Agreement Number 1663


P.A. No. 1663               D-1                          SA7


Exhibit D-1 Page 1


                     PRICE ADJUSTMENT DUE TO
                      ECONOMIC FLUCTUATIONS
                    AIRFRAME PRICE ADJUSTMENT
   BLOCK B "A" MARKET AIRCRAFT AND BLOCK C "B" MARKET AIRCRAFT
                        (1995 Base Price)


1.     Formula.
       -------

       The Airframe Price Adjustment will be determined at the
time of Aircraft delivery in accordance with the following
formula:

       Pa = (P)(L + M - 1)

       Where:

            Pa = Airframe Price Adjustment

            L = .65 x ECI
                    -----
                    130.1

            M = .35 x ICI
                    -----
                    123.6

            P = Aircraft Basic Price (as set forth in Article 3.2
                of this Agreement) less the base price of Engines
               (as defined in this Exhibit D-1) in the amount of:

                [*CONFIDENTIAL MATERIAL OMITTED AND FILED
                SEPARATELY WITH THE SECURITIES AND EXCHANGE
                COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL
                TREATMENT] {Block B "A" Market Aircraft}

                [*CONFIDENTIAL MATERIAL OMITTED AND FILED
                SEPARATELY WITH THE SECURITIES AND EXCHANGE
                COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL
                TREATMENT] {Block C "B" Market Aircraft}

ECI = A value using the "Employment Cost Index for workers in
aerospace manufacturing" (aircraft manufacturing, standard
industrial classification code 3721, compensation, base month and
year June 1989 = 100), as released by the Bureau of Labor
Statistics, U.S. Department of Labor on a quarterly basis for the
months of March, June, September and December, calculated as
follows:  A three-month arithmetic average value (expressed as a
decimal and rounded to the nearest tenth) will be determined
using the months set forth in the table below for the applicable
Aircraft, with the released Employment Cost Index value described
above for the month of March also being used for the months of
January and February; the value for June also used for April and
May; the value for September also used for July and August; and
the value for December also used for October and November.

ICI = The three-month arithmetic average of the released monthly
values for the Industrial Commodities Index as set forth in the
"Producer Prices and Price Index" (Base


P.A. No. 1663                D-1-1                        SA7


Exhibit D-1 Page 2


Year 1982 = 100) as released by the Bureau of Labor Statistics,
U.S. Department of Labor values (expressed as a decimal and
rounded to the nearest tenth) for the months set forth in the
table below for the applicable Aircraft.

     In determining the value of L, the ratio of ECI divided by
130.1 will be expressed as a decimal rounded to the nearest ten-
thousandth and then multiplied by .65 with the resulting value
also expressed as a decimal and rounded to the nearest ten-
thousandth.

     In determining the value of M, the ratio of ICI divided by
123.6 will be expressed as a decimal rounded to the nearest ten-
thousandth and then multiplied by .35 with the resulting value
also expressed as a decimal and rounded to the nearest ten-
thousandth.

                                  Months to be Utilized
Month of Scheduled                in Determining the
Aircraft Delivery                 Value of ECI and ICI
- -----------------                 --------------------

January                           June B, July B, Aug. B
February                          July B, Aug. B, Sept. B
March                             Aug. B, Sept. B, Oct. B
April                             Sept. B, Oct. B, Nov. B
May                               Oct. B, Nov. B, Dec. B
June                              Nov. B, Dec. B, Jan. D
July                              Dec. B, Jan. D, Feb. D
August                            Jan. D, Feb. D, Mar. D
September                         Feb. D, Mar. D, Apr. D
October                           Mar. D, Apr. D, May D
November                          Apr. D, May D, June D
December                          May D, June D, July D

The following definitions of B and D will apply:

     B = The calendar year before the year in which the
         Scheduled month of delivery as set forth in Article
         2.1 occurs.

     D = The calendar year during which the scheduled month of
         delivery as set forth in Article 2.1 occurs.

2.     If at any time of delivery of an Aircraft Boeing is unable
to determine the Airframe Price Adjustment because the applicable
values to be used to determine the ECI and ICI have not been
released by the Bureau of Labor Statistics, then:

       2.1     The Airframe Price Adjustment, to be used at the
time of delivery of each of the Aircraft, will be determined by
utilizing the escalation provisions set forth above.  The values
released by the Bureau of Labor Statistics and available to
Boeing 30 days prior to scheduled Aircraft delivery will be used
to determine the ECI and ICI values for the applicable months


P.A. No. 1663              D-1-2                        SA7


Exhibit D-1 Page 3


(including those noted as preliminary by the Bureau of Labor
Statistics) to calculate the Airframe Price Adjustment.  If no
values have been released for an applicable month, the provisions
set forth in Paragraph 2.2 below will apply.  If prior to
delivery of an Aircraft the U.S. Department of Labor changes the
base year for determination of the ECI or ICI values as defined
above, such rebased values will be incorporated in the Airframe
Price Adjustment calculation.  The payment by Buyer to Boeing of
the amount of the Purchase Price for such Aircraft, as determined
at the time of Aircraft delivery, will be deemed to be the
payment for such Aircraft required at the delivery thereof.

     2.2     If prior to delivery of an Aircraft the U.S.
Department of Labor substantially revises the methodology used
for the determination of the values to be used to determine the
ECI and ICI values (in contrast to benchmark adjustments or other
corrections of previously released values), or for any reason has
not released values needed to determine the applicable Aircraft
Airframe Price Adjustment, the parties will, prior to delivery of
any such Aircraft, select a substitute for such values from data
published by the Bureau of Labor Statistics for other similar
data reported by non-governmental United States organizations,
such substitute to lead in application to the same adjustment
result, insofar as possible, as would have been achieved by
continuing the use of the original values as they may have
fluctuated during the applicable time period.  Appropriate
revision of the formula will be made as required to reflect any
substitute values.  However, if within 24 months from delivery of
the Aircraft the Bureau of Labor Statistics should resume
releasing values for the months needed to determine the Airframe
Price Adjustment, such values will be used to determine any
increase or decrease in the Airframe Price Adjustment for the
Aircraft from that determined at the time of delivery of such
Aircraft.

     2.3     In the event escalation provisions are made non-
enforceable or otherwise rendered null and void by any agency of
the United States Government, the parties agree, to the extent
they may lawfully do so, to equitably adjust the Purchase Price
of any affected Aircraft to reflect an allowance for increases or
decreases in labor compensation and material costs occurring
since February, 1995, which is consistent with the applicable
provisions of paragraph 1 of this Exhibit D-1.

3.     For the calculations herein, the values released by the
Bureau of Labor Statistics and available to Boeing 30 days prior
to scheduled Aircraft delivery will be used to determine the ECI
and ICI values for the applicable months (including those noted
as preliminary by the Bureau of Labor Statistics) to calculate
the Airframe Price Adjustment.

Note:     Any rounding of a number, as required under this
- ----      Exhibit D-1 with respect to escalation of the airframe
          price, will be accomplished as follows:  if the first
          digit of the portion to be dropped from the number to
          be rounded is five or greater, the preceding digit will
          be raised to the next higher number.


P.A. No. 1663              D-1-3                          SA7


Exhibit D-1 Page 4


            ENGINE PRICE ADJUSTMENT - PRATT & WHITNEY
   BLOCK B "A" MARKET AIRCRAFT AND BLOCK C "B" MARKET AIRCRAFT
                        (1995 BASE PRICE)


(a)     The Aircraft Basic Price of each Block B "A" Market
Aircraft and Block C "B" Market Aircraft set forth in Article 3.2
of this Agreement includes an aggregate price for engines and all
accessories, equipment and parts therefor provided by the engine
manufacturer (collectively in this Exhibit D-1 called "Engines")
of [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE
SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR
CONFIDENTIAL TREATMENT].  The adjustment in Engine price
applicable to each Aircraft ("Engine Price Adjustment" herein)
will be determined at the time of Aircraft delivery in accordance
with the following formula:

        Pa = (P)(AA + BB + CC)-P

(b)     The following definitions will apply herein:

        Pa = Engine Price Adjustment

        P = Aggregate Engine Base Price as set forth in paragraph
           (a) above.

        AA = .60 x   L
                 ---------
                  $17.80

        BB = .30 x   M
                 ---------
                   130.6

        CC = .10 x   E
                 ---------
                   76.6

In determining the value of AA, BB and CC, the ratio of L divided
by $17.80, M divided by 130.6 and E divided by 76.6 will be
expressed as a decimal and rounded to the nearest ten-thousandth
but the decimal value resulting from multiplying such ratios by
the respective constants (.60, .30 and .10) will not be rounded.
The value of the sum of AA + BB + CC will also be rounded to the
nearest ten-thousandth.

        L = Labor Index, which is the "Hourly Earnings of
            Aircraft Engines and Engine Parts Production Workers,
            SIC 3724" published by the Bureau of Labor
            Statistics, U.S. Department of Labor, for the
            seventh month preceding the month of scheduled
            Aircraft delivery.

        $17.80 = Published Labor Index (SIC 3724) for December,
                 1994.


P.A. No. 1663              D-1-4                         SA7


Exhibit D-1 Page 5


        M = Material Index, which is the "Producer Price Index -
            Code 10, Metals and Metal Products," (Base Year 1982
            = 100) published by the Bureau of Labor Statistics,
            U.S. Department of Labor, for the seventh month
            preceding the month of scheduled Aircraft delivery.

        130.6 = Published Material Index (Code 10) for December,
                1994.

        E = Fuel Index, which is the "Producer Price Index -
            Code 5, Fuels and Related Products and Power" (Base
            Year 1982 = 100) published for the Bureau of Labor
            Statistics, U.S. Department of Labor, for the seventh
            Month preceding the month of scheduled Aircraft
            Delivery.

        76.6 = Published Fuel Index (Code 5) for December, 1994.

The Engine Price Adjustment will not be made if it would result
in a decrease in the aggregate Engine base price.

(c)     The value of the Labor, Material and Fuel Index used in
determining the Engine Price Adjustment will be those published
by the Bureau of Labor Statistics, U.S. Department of Labor as of
a date 30 days prior to the scheduled Aircraft delivery to Buyer.
Such Index values will be considered final and no revision to the
Engine Price Adjustment will be made after Aircraft delivery for
any subsequent changes in published Index values.

(d)     If the Bureau of Labor Statistics, U.S. Department of
Labor, (i) substantially revises the methodology (in contrast to
benchmark adjustments or other corrections of previously
published data), or (ii) discontinues publication of any of the
data referred to above or (iii) temporarily discontinues
publication of any of the data referred to above, Pratt & Whitney
Aircraft (P&WA) agrees to meet jointly with Boeing and Buyer and
jointly select a substitute for the revised or discontinued data,
such substitute data to lead in application to the same
adjustment result, insofar as possible, as would have been
achieved by continuing the use of the original data as it may
have fluctuated had it not been revised or discontinued.
Appropriate revision of the Engine Price Adjustment provisions
set forth above will be made to accomplish this result for
affected Engines.

In the event the Engine Price Adjustment escalation provisions of
this Agreement are made non-enforceable or otherwise rendered
null and void by any agency of the United States Government, P&WA
agrees to meet with Boeing and jointly agree, to the extent that
they may lawfully do so, to adjust equitably the purchase price
of the Engine(s) to reflect an allowance for increases in labor,
material and fuel costs that occurred from December, 1994 to the
seventh month preceding the month of scheduled delivery of the
applicable Aircraft.

NOTES:  Any rounding of a number, as required under this Exhibit
D-1 with respect to escalation of the Engine price, will be
accomplished as follows:  if the first digit of the portion to be
dropped from the number to be rounded is five or greater, the
preceding digit will be raised to the next higher number.


P.A. No. 1663                 D-1-5                      SA7


Attachment to Letter Agreement
No. 6-1162-DLJ-1193
PW4077 Engines
Page 1





              MODEL 777-222 PERFORMANCE GUARANTEES
                                
                   FOR UNITED AIR LINES, INC.




SECTION                     CONTENTS

   1                AIRCRAFT MODEL APPLICABILITY

   2                FLIGHT PERFORMANCE

   3                MANUFACTURER'S EMPTY WEIGHT

   4                AIRCRAFT CONFIGURATION

   5                GUARANTEE CONDITIONS

   6                GUARANTEE COMPLIANCE

   7                EXCLUSIVE GUARANTEES



P.A. No. 1663
AERO-B-B111-M98-0513                                 SS98-0375


Attachment to Letter Agreement
No. 6-1162-DLJ-1193
PW4077 Engines
Page 2


1      AIRCRAFT MODEL APPLICABILITY

       The guarantees contained in this Attachment (the
"Performance Guarantees") are applicable to the 777-222 Aircraft
with a maximum takeoff weight of at least 545,000 pounds, a
maximum landing weight of 445,000 pounds, and a maximum zero fuel
weight of 420,000 pounds, and equipped with Boeing furnished
PW4077 engines.

2      FLIGHT PERFORMANCE

2.1    Mission

2.1.1  Mission Payload

       The payload for a stage length of [*CONFIDENTIAL MATERIAL
OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]
using the conditions and operating rules defined below, shall not
be less than the following guarantee value:

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

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

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

     Conditions and operating rules:

     Stage      The stage length is defined as the sum of the
     Length:    distances for the climb, cruise, and descent.

     Takeoff:   The airport altitude is 364 feet.

                The airport temperature is 44 degrees Fahrenheit.

                The runway length is 13,123 feet prior to
                subtracting the lineup allowance.

                The takeoff lineup allowance is 270 feet.

                The runway slope is 0.30 percent downhill.


P.A. No. 1663
AERO-B-B111-M98-0513                                SS98-0375


Attachment to Letter Agreement
No. 6-1162-DLJ-1193
PW4077 Engines
Page 3

                The following obstacle definition is based on a
                straight-out departure where obstacle height and
                distance are specified with reference to the
                liftoff end of the runway:

                              Distance              Height
                         1.   7 feet               5 feet
                         2.   4282 feet            101 feet
                         3.   4725 feet            107 feet

                Maximum takeoff thrust is used for the takeoff.

                The takeoff gross weight shall conform to FAA
                Regulations.

     Climbout   Following the takeoff to 35 feet, the Aircraft
     Maneuver:  accelerates to 250 KCAS while climbing to 1,500
                feet above the departure airport altitude and
                retracting flaps and landing gear.

     Climb:     The Aircraft climbs from 1,500 feet above the
                departure airport altitude to 10,000 feet
                altitude at 250 KCAS.

                The Aircraft then accelerates at a rate of climb
                of 500 feet per minute to a climb speed of 315
                KCAS.

                The climb continues at 315 KCAS until 0.83 Mach
                number is reached.

                The climb continues at 0.83 Mach number to the
                initial cruise altitude.

                The temperature is ISA+10 degrees Celsius during climb.

                Maximum climb thrust is used during climb.

     Cruise:    The Aircraft cruises at 0.84 Mach number.

                The initial cruise altitude is 35,000 feet.

P.A. No. 1663
AERO-B-B111-M98-0513                                 SS98-0375


Attachment to Letter Agreement
No. 6-1162-DLJ-1193
PW4077 Engines
Page 4



                A step climb or multiple step climbs of
                4,000 feet altitude may be used when
                beneficial to minimize fuel burn.

                The temperature is ISA+10 degrees Celsius during cruise.

                The cruise thrust is not to exceed maximum
                cruise thrust except during a step climb when
                maximum climb thrust may be used.

     Descent:   The Aircraft descends from the final cruise
                altitude at 0.83 Mach number until 300 KCAS is
                reached.

                The descent continues at 300 KCAS to an altitude
                of 10,000 feet.  At that altitude the Aircraft
                decelerates to 250 KCAS.

                The descent continues at 250 KCAS to an altitude
                of 1,500 feet above the destination airport
                altitude.

                Throughout the descent, the cabin pressure will
                be controlled to a maximum rate of descent
                equivalent to 300 feet per minute at sea level.

                The temperature is ISA+10 degrees Celsius during descent.

     Approach   The Aircraft decelerates to the final approach
     and        speed while extending landing gear and flaps,
     Landing    then descends and lands.
     Maneuver:

                The destination airport altitude is 667 feet.

     Fixed      For the purpose of this guarantee and for the
     Allow-     purpose of establishing compliance with this
     ances:     guarantee, the following shall be used as fixed
                quantities and allowances:

                Taxi-out:
                            Fuel              570 Pounds

                Takeoff and Climbout Maneuver:
                            Fuel              1,490 Pounds
                            Distance          0 Nautical Miles


P.A. No. 1663
AERO-B-B111-M98-0513                                   SS98-0375


Attachment to Letter Agreement
No. 6-1162-DLJ-1193
PW4077 Engines
Page 5



                Approach and Landing Maneuver:
                           Fuel               520 Pounds

                Taxi-in (shall be consumed from the reserve
                fuel):
                           Fuel               290 Pounds

                Usable reserve fuel remaining upon completion of
                the approach and landing maneuver:  20,000
                Pounds

2.1.2     Operational Empty Weight Basis

          The Operational Empty Weight (OEW) derived in
          Paragraph 2.1.3 is the basis for the mission guarantee
          of Paragraph 2.1.1.


P.A. No. 1663
AERO-B-B111-M98-0513                                    SS98-0375


Attachment to Letter Agreement
No. 6-1162-DLJ-1193
PW4077 Engines
Page 6



2.1.3     777-222 Weight Summary of United Air Lines, Inc.


                                                   Pounds
                                                   ------

Customer Configuration specification MEW          [*CONFIDENTIAL
     Configuration Specification [*CONFIDENTIAL    MATERIAL
        MATERIAL OMITTED AND FILED SEPARATELY      OMITTED AND
        WITH THE SECURITIES AND EXCHANGE           FILED SEP-
        COMMISSION PURSUANT TO A REQUEST           ARATELY WITH
        FOR CONFIDENTIAL TREATMENT]                THE SECURITIES
                                                   AND EXCHANGE
                                                   COMMISSION
                                                   PURSUANT TO A
                                                   REQUEST FOR
                                                   CONFIDENTIAL
                                                   TREATMENT]
     292 (12F/49C/231Y) Passengers
     PW4077 Engine
     [*CONFIDENTIAL MATERIAL OMITTED AND FILED
     SEPARATELY WITH THE SECURITIES AND EXCHANGE
     COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL
     TREATMENT] Maximum Taxi Weight
     [*CONFIDENTIAL MATERIAL OMITTED AND FILED
     SEPARATELY WITH THE SECURITIES AND EXCHANGE
     COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL
     TREATMENT] Fuel Capacity

Changes for United Air Lines, Inc.
[*CONFIDENTIAL MATERIAL OMITTED AND FILED       [*CONFIDENTIAL
SEPARATELY WITH THE SECURITIES AND EXCHANGE      MATERIAL OMITTED
COMMISSION PURSUANT TO A REQUEST FOR             AND FILED
CONFIDENTIAL TREATMENT]                          SEPARATELY WITH
                                                 THE SECURITIES
                                                 AND EXCHANGE
                                                 COMMISSION
                                                 PURSUANT TO A
                                                 REQUEST FOR
                                                 CONFIDENTIAL
                                                 TREATMENT]



United Air Lines, Inc. Manufacturer's Empty
Weight (MEW)*                                   [*CONFIDENTIAL
                                                 MATERIAL OMITTED
                                                 AND FILED
                                                 SEPARATELY WITH
                                                 THE SECURITIES
                                                 AND EXCHANGE
                                                 COMMISSION
                                                 PURSUANT TO A
                                                 REQUEST FOR
                                                 CONFIDENTIAL
                                                 TREATMENT]

Standard and Operational Items Allowance         [*CONFIDENTIAL
       (Paragraph 2.1.4)                         MATERIAL OMITTED
                                                 AND FILED
                                                 SEPARATELY WITH
                                                 THE SECURITIES
                                                 AND EXCHANGE
                                                 COMMISSION
                                                 PURSUANT TO A
                                                 REQUEST FOR
                                                 CONFIDENTIAL
                                                 TREATMENT]

United Air Lines, Inc. Operational Empty
Weight (OEW)                                    [*CONFIDENTIAL
                                                 MATERIAL OMITTED
                                                 AND FILED
                                                 SEPARATELY WITH
                                                 THE SECURITIES
                                                 AND EXCHANGE
                                                 COMMISSION
                                                 PURSUANT TO A
                                                 REQUEST FOR
                                                 CONFIDENTIAL
                                                 TREATMENT]


                              Quantity       Pounds       Pounds

*Seat Weight Included:        [*CONFIDENTIAL MATERIAL OMITTED AND
                               FILED SEPARATELY WITH THE SECURITIES
                               AND EXCHANGE COMMISSION PURSUANT
                               TO A REQUEST FOR CONFIDENTIAL TREAT-
                               MENT]

First Class Doubles

Business Class Doubles

Business Class Triples

Economy Class Doubles

Economy Class Quadruples

Economy Class Quintuples


P.A. No. 1663
AERO-B-B111-M98-0513                                  SS98-0375


Attachment to Letter Agreement
No. 6-1162-DLJ-1193
PW4077 Engines
Page 7


2.1.4     Standard and Operational Items Allowance


                                Qty    Pounds    Pounds    Pounds

Standard Items Allowance        [*CONFIDENTIAL MATERIAL OMITTED
                                 AND FILED SEPARATELY WITH THE
     Unusable Fuel               SECURITIES AND EXCHANGE
     Oil                         COMMISSION PURSUANT TO A
     Oxygen Equipment            REQUEST FOR CONFIDENTIAL
       Passenger Portable        TREATMENT]
     Miscellaneous Equipment
       First Aid Kits
       Crash Axe
       Megaphones
       Flashlights
       Fire Gloves
       Smoke Goggles
       Smoke Hoods
       Medical Kit
     Galley Structure & Fixed Inserts

Operational Items Allowance

     Crew and Crew Baggage
       Flight Crew
       Cabin Crew
     Catering Allowance
     [*CONFIDENTIAL MATERIAL
     OMITTED AND FILED
     SEPARATELY WITH
     THE SECURITIES AND
     EXCHANGE COMMISSION
     PURSUANT TO A REQUEST
     FOR CONFIDENTIAL
     TREATMENT]
       First Class
       Business Class
       Economy Class
     Passenger Service Equipment
     Potable Water
     Waste Tank Disinfectant
     Emergency Equipment
       Slide Rafts
       Passenger Life Vests
       Flight Crew Life Vests
       Locator Transmitter
     Cargo System
       LD-3 Containers
Total Standard and Operational Allowance


P.A. No. 1663
AERO-B-B111-M98-0513                                 SS98-0375


Attachment to Letter Agreement
No. 6-1162-DLJ-1193
PW4077 Engines
Page 8


3      MANUFACTURER'S EMPTY WEIGHT

       The Manufacturer's Empty Weight (MEW) is guaranteed not to
exceed the [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY
WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST
FOR CONFIDENTIAL TREATMENT].

4      AIRCRAFT CONFIGURATION

4.1    The guarantees contained in this Attachment are based on
the Aircraft configuration as defined in Revision H of Detail
Specification [*CONFIDENTIAL MATERIAL OMITTED AND FILED
SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT
TO A REQUEST FOR CONFIDENTIAL TREATMENT] (hereinafter referred to
as the Detail Specification).  Appropriate adjustment shall be
made for changes in such Detail Specification approved by the
Customer and Boeing or otherwise allowed by the Purchase
Agreement which cause changes to the flight performance and/or
weight and balance of the Aircraft.  Such adjustment shall be
accounted for by Boeing in its evidence of compliance with the
guarantees.

4.2     The guarantee payload of Paragraph 2.1.1 will be adjusted
by Boeing for the effect of the following on OEW and the
Manufacturer's Empty Weight guarantee of Section 3 will be
adjusted by Boeing for the following in its evidence of
compliance with the guarantees:

        (1)     Changes to the Detail Specification including
Change Requests, Change Orders, Optional Features or any other
changes mutually agreed upon between the Customer and Boeing or
otherwise allowed by the Purchase Agreement.

        (2)     The difference between the component weight
allowances given in Appendix IV of the Detail Specification and
the actual weights.

5       GUARANTEE CONDITIONS

5.1     All guaranteed performance data are based on the ICAO
International Standard Atmosphere (ISA) and specified variations
therefrom; altitudes are pressure altitudes.

5.2     The FAA Regulations (FAR) referred to in this Attachment
are, unless otherwise specified, the 777-200 Certification Basis
regulations specified in the Type Certificate Data Sheet
T-00001SE, Revision 4, dated April 18, 1996.

5.3     In the event a change is made to any law, governmental
regulation or requirement, or in the interpretation of any such
law, governmental


P.A. No. 1663
AERO-B-B111-M98-0513                                    SS98-0375


Attachment to Letter Agreement
No. 6-1162-DLJ-1193
PW4077 Engines
Page 9



regulation or requirement that affects the certification basis
for the Aircraft as described in Paragraph 5.2, and as a result
thereof, a change is made to the configuration and/or the
performance of the Aircraft in order to obtain certification, the
guarantees set forth in this Attachment shall be appropriately
modified to reflect any such change.

5.4     The takeoff portion of the mission guarantee is based on
hard surface, level and dry runway with no wind or obstacles, no
clearway or stopway, 235 mph tires, with anti-skid operative, and
with the Aircraft center of gravity at the most forward limit
unless otherwise specified.  The takeoff performance is based on
no engine bleed for air conditioning or thermal anti-icing and
the Auxiliary Power Unit(APU) turned off unless otherwise
specified.  Unbalanced field length calculations and the improved
climb performance procedure will be used for takeoff as required.

5.5     The climb, cruise and descent portions of the mission
guarantee include allowances for normal power extraction and
engine bleed for normal operation of the air conditioning system.
Normal electrical power extraction shall be defined as not less
than a 212 kilowatts total electrical load.  Normal operation of
the air conditioning system shall be defined as pack switches in
the "Auto" position, the temperature control switches in the
"Auto" position that results in a nominal cabin temperature of
75 degrees Fahrenheit, and all air conditioning systems operating 
normally.  This operation allows a maximum cabin pressure differential 
of 8.6 pounds per square inch at higher altitudes, with a nominal
Aircraft cabin ventilation rate of 7,600 cubic feet per minute
including passenger cabin recirculation (nominal recirculation is
50 percent).  The APU is turned off unless otherwise specified.

5.6     The climb, cruise and descent portions of the mission
guarantee are based on an Aircraft center of gravity location as
determined by Boeing, not to be aft of 30 percent of the mean
aerodynamic chord.

5.7     Performance, where applicable, is based on a fuel Lower
Heating Value (LHV) of 18,580 BTU per pound and a fuel density of
6.70 pounds per U.S. gallon.

6       GUARANTEE COMPLIANCE

6.1     Compliance with the guarantees of Sections 2 and 3 shall
be based on the conditions specified in those sections, the
Aircraft configuration of Section 4 and the guarantee conditions
of Section 5.


P.A. No. 1663
AERO-B-B111-M98-0513                                   SS98-0375


Attachment to Letter Agreement
No. 6-1162-DLJ-1193
PW4077 Engines
Page 10



6.2     Compliance with the takeoff portion of the mission
guarantee shall be based on the FAA approved Airplane Flight
Manual for the Model 777-200.

6.3     Compliance with the climb, cruise and descent portions of
the mission guarantee shall be established by calculations based
on flight test data obtained from an aircraft in a configuration
similar to that defined by the Detail Specification.

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

6.5     Compliance with the Manufacturer's Empty Weight guarantee
shall be based on information in the "Weight and Balance Control
and Loading Manual - Aircraft Report."

6.6     The data derived from tests shall be adjusted as required
by conventional methods of correction, interpolation or
extrapolation in accordance with established engineering
practices to show compliance with these guarantees.

6.7     Compliance shall be based on the performance of the
airframe and engines in combination, and shall not be contingent
on the engine meeting its manufacturer's performance
specification.

7       EXCLUSIVE GUARANTEES

        The only performance guarantees applicable to the
Aircraft are those set forth in this Attachment.


P.A. No. 1663
AERO-B-B111-M98-0513                                  SS98-0375


Attachment to Letter Agreement
No. 6-1162-RCN-925
PW4090 Engines
Page 1





             MODEL 777-222ER PERFORMANCE GUARANTEES
                                
                   FOR UNITED AIR LINES, INC.




SECTION                     CONTENTS

   1                AIRCRAFT MODEL APPLICABILITY

   2                FLIGHT PERFORMANCE

   3                MANUFACTURER'S EMPTY WEIGHT

   4                AIRCRAFT CONFIGURATION

   5                GUARANTEE CONDITIONS

   6                GUARANTEE COMPLIANCE

   7                EXCLUSIVE GUARANTEES


P.A. No. 1663
AERO-B-B111-M98-0520                                 SS98-0403


Attachment to Letter Agreement
No. 6-1162-RCN-925
PW4090 Engines
Page 2


1      AIRCRAFT MODEL APPLICABILITY

       The guarantees contained in this Attachment (the
"Performance Guarantees") are applicable to the 777-222ER
Aircraft with a maximum takeoff weight of at least 624,700
pounds, a maximum landing weight of 460,000 pounds, and a maximum
zero fuel weight of 430,000 pounds, and equipped with Boeing
furnished PW4090 engines.

2      FLIGHT PERFORMANCE

2.1    Mission

2.1.1  Mission Payload

       The payload for a stage length of [*CONFIDENTIAL MATERIAL
OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]
using the conditions and operating rules defined below, shall not
be less than the following guarantee value:

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

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

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

     Conditions and operating rules:

     Stage      The stage length is defined as the sum of the
     Length:    distances for the climb, cruise, and descent.

     Takeoff:   The airport altitude is 387 feet.

                The airport temperature is 46 degrees Fahrenheit.

                The runway length is 11,860 feet prior to
                subtracting the lineup allowance.

                The takeoff lineup allowance is 270 feet.

                The runway slope is 0.23 percent uphill.


P.A. No. 1663
AERO-B-B111-M98-0520                                SS98-0403


Attachment to Letter Agreement
No. 6-1162-RCN-925
PW4090 Engines
Page 3




                The following obstacle definition is based on a
                straight-out departure where obstacle height and
                distance are specified with reference to the
                liftoff end of the runway:

                              Distance              Height
                         1.   1641 feet            26 feet
                         2.   3462 feet            46 feet

                Maximum takeoff thrust is used for the takeoff.

                The takeoff gross weight shall conform to FAA
                Regulations.

     Climbout   Following the takeoff to 35 feet, the Aircraft
     Maneuver:  accelerates to 250 KCAS while climbing to 1,500
                feet above the departure airport altitude and
                retracting flaps and landing gear.

     Climb:     The Aircraft climbs from 1,500 feet above the
                departure airport altitude to 10,000 feet
                altitude at 250 KCAS.

                The Aircraft then accelerates at a rate of climb
                of 500 feet per minute to a climb speed of 315
                KCAS.

                The climb continues at 315 KCAS until 0.83 Mach
                number is reached.

                The climb continues at 0.83 Mach number to the
                initial cruise altitude.

                The temperature is ISA+10 degrees Celsius during climb.

                Maximum climb thrust is used during climb.

     Cruise:    The Aircraft cruises at 0.84 Mach number.

                The initial cruise altitude is 31,000 feet.

                A step climb or multiple step climbs of
                4,000 feet altitude may be used when beneficial
                to minimize fuel burn.


P.A. No. 1663
AERO-B-B111-M98-0520                                 SS98-0403


Attachment to Letter Agreement
No. 6-1162-RCN-925
PW4090 Engines
Page 4



                The temperature is ISA+10 degrees Celsius during cruise.

                The cruise thrust is not to exceed maximum
                cruise thrust except during a step climb when
                maximum climb thrust may be used.

     Descent:   The Aircraft descends from the final cruise
                altitude at 0.83 Mach number until 300 KCAS is
                reached.

                The descent continues at 300 KCAS to an altitude
                of 10,000 feet.  At that altitude the Aircraft
                decelerates to 250 KCAS.

                The descent continues at 250 KCAS to an altitude
                of 1,500 feet above the destination airport
                altitude.

                Throughout the descent, the cabin pressure will
                be controlled to a maximum rate of descent
                equivalent to 300 feet per minute at sea level.

                The temperature is ISA+10 degrees Celsius during descent.

     Approach   The Aircraft decelerates to the final approach
     and        speed while extending landing gear and flaps,
     Landing    then descends and lands.
     Maneuver:

                The destination airport altitude is 126 feet.

     Fixed      For the purpose of this guarantee and for the
     Allow-     purpose of establishing compliance with this
     ances:     guarantee, the following shall be used as fixed
                quantities and allowances:

                Taxi-out:
                            Fuel              570 Pounds

                Takeoff and Climbout Maneuver:
                            Fuel              1,750 Pounds
                            Distance          0 Nautical Miles


                Approach and Landing Maneuver:
                           Fuel               520 Pounds



P.A. No. 1663
AERO-B-B111-M98-0520                                   SS98-0403


Attachment to Letter Agreement
No. 6-1162-RCN-925
PW4090 Engines
Page 5


                Taxi-in (shall be consumed from the reserve
                fuel):
                           Fuel               290 Pounds

                Usable reserve fuel remaining upon completion of
                the approach and landing maneuver:  20,000
                Pounds

2.1.2     Operational Empty Weight Basis

          The Operational Empty Weight (OEW) derived in
          Paragraph 2.1.3 is the basis for the mission guarantee
          Of Paragraph 2.1.1.


P.A. No. 1663
AERO-B-B111-M98-0520                                    SS98-0403


Attachment to Letter Agreement
No. 6-1162-RCN-925
PW4090 Engines
Page 6




2.1.3     777-222ER Weight Summary - United Air Lines, Inc.


                                                   Pounds

Standard Model Specification MEW                  [*CONFIDENTIAL
     Configuration Specification: [*CONFIDENTIAL   MATERIAL
        MATERIAL OMITTED AND FILED SEPARATELY      OMITTED AND
        WITH THE SECURITIES AND EXCHANGE           FILED SEP-
        COMMISSION PURSUANT TO A REQUEST           ARATELY WITH
        FOR CONFIDENTIAL TREATMENT]                THE SECURITIES
                                                   AND EXCHANGE
                                                   COMMISSION
                                                   PURSUANT TO A
                                                   REQUEST FOR
                                                   CONFIDENTIAL
                                                   TREATMENT]
     Passengers:  305 (24F/54C/227Y) (Ref. 0130CG2707)
     Engines:  Two PW4084 engines rated at 84,600
          Pounds thrust (Ref. 7200CG7010)
     Fuel Capacity:  [*CONFIDENTIAL MATERIAL
          OMITTED AND FILED SEPARATELY WITH THE
          SECURITIES AND EXCHANGE COMMISSION
          PURSUANT TO A REQUEST FOR CONFIDENTIAL
          TREATMENT] U.S. Gallons
     Maximum Taxi Weight:  [*CONFIDENTIAL MATERIAL
          OMITTED AND FILED SEPARATELY WITH THE
          SECURITIES AND EXCHANGE COMMISSION
          PURSUANT TO A REQUEST FOR CONFIDENTIAL
          TREATMENT] pounds

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

Changes for:  United Air Lines, Inc.
                                                [*CONFIDENTIAL
                                                 MATERIAL OMITTED
                                                 AND FILED
                                                 SEPARATELY WITH
                                                 THE SECURITIES
                                                 AND EXCHANGE
                                                 COMMISSION
                                                 PURSUANT TO A
                                                 REQUEST FOR
                                                 CONFIDENTIAL
                                                 TREATMENT]

United Air Lines, Inc. Manufacturer's Empty     [*CONFIDENTIAL
Weight (MEW)*                                    MATERIAL OMITTED
                                                 AND FILED
                                                 SEPARATELY WITH
                                                 THE SECURITIES
                                                 AND EXCHANGE
                                                 COMMISSION
                                                 PURSUANT TO A
                                                 REQUEST FOR
                                                 CONFIDENTIAL
                                                 TREATMENT]

Standard and Operational Items Allowance         [*CONFIDENTIAL
       (Paragraph 2.1.4)                         MATERIAL OMITTED
                                                 AND FILED
                                                 SEPARATELY WITH
                                                 THE SECURITIES
                                                 AND EXCHANGE
                                                 COMMISSION
                                                 PURSUANT TO A
                                                 REQUEST FOR
                                                 CONFIDENTIAL
                                                 TREATMENT]

Round off                                        -5

United Air Lines, Inc. Operational Empty        [*CONFIDENTIAL
Weight (OEW)                                     MATERIAL OMITTED
                                                 AND FILED
                                                 SEPARATELY WITH
                                                 THE SECURITIES
                                                 AND EXCHANGE
                                                 COMMISSION
                                                 PURSUANT TO A
                                                 REQUEST FOR
                                                 CONFIDENTIAL
                                                 TREATMENT]


P.A. No. 1663
AERO-B-B111-M98-0520                                  SS98-0403


Attachment to Letter Agreement
No. 6-1162-RCN-925
PW4090 Engines
Page 7



*Weight Included in MEW:


                              Quantity       Pounds       Pounds

Seats - United Airlines       [*CONFIDENTIAL MATERIAL OMITTED
Vendor Weights (Includes       AND FILED SEPARATELY WITH THE
passenger telephone            SECURITIES AND EXCHANGE COMMISSION
and in-seat video units)       PURSUANT TO A REQUEST FOR CON-
                               FIDENTIAL TREATMENT]

First Class
Sleeper Doubles

Business Class
Doubles

Business Class
Triples

Business Class
Back Row
Triples

Economy Class
Front Row
Doubles

Economy Class
Doubles

Economy Class
Back Row
Doubles

Economy Class
Front Row
Quadruples

Economy Class
Quadruples

Economy Class
Back Row
Quadruples

Economy Class
Front Row
Quintuples

Economy Class
Quintuples

Economy Class
Back Row
Quintuples

Engines

Pratt & Whitney PW4090
     Bare Engine plus Pratt & Whitney
     engine buildup and residual fluids


P.A. No. 1663
AERO-B-B111-M98-0520                                  SS98-0403


Attachment to Letter Agreement
No. 6-1162-RCN-925
PW4090 Engines
Page 8


2.1.4     Standard and Operational Items Allowance


                                Qty    Pounds    Pounds    Pounds

Standard Items Allowance        [*CONFIDENTIAL MATERIAL OMITTED
                                 AND FILED SEPARATELY WITH THE
     Unusable Fuel               SECURITIES AND EXCHANGE
     Oil                         COMMISSION PURSUANT TO A
     Oxygen Equipment            REQUEST FOR CONFIDENTIAL
       Passenger Portable        TREATMENT]
     Miscellaneous Equipment
       First Aid Kits
       Crash Axe
       Megaphones
       Flashlights
       Smoke Goggles
       Smoke Hoods
       Medical Kit
       Fire Gloves
     Galley Structure & Fixed Inserts

Operational Items Allowance

     Crew and Crew Baggage
       Flight Crew
       Cabin Crew
     Catering Allowance [*CON-
     FIDENTIAL MATERIAL
     OMITTED AND FILED
     SEPARATELY WITH
     THE SECURITIES AND
     EXCHANGE COMMISSION
     PURSUANT TO A REQUEST
     FOR CONFIDENTIAL
     TREATMENT]
       First Class
       Business Class
       Economy Class
     Passenger Service Equipment
     Potable Water
     Waste Tank Disinfectant
     Emergency Equipment
       Slide Rafts
       Passenger Life Vests
       Crew Life Vests
       Locator Transmitter
     Cargo System
       Containers(LD-3)

Total Standard and Operational Items


P.A. No. 1663
AERO-B-B111-M98-0520                                 SS98-0403


Attachment to Letter Agreement
No. 6-1162-RCN-925
PW4090 Engines
Page 9


3      MANUFACTURER'S EMPTY WEIGHT

       The Manufacturer's Empty Weight (MEW) is guaranteed not to
exceed the [* CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH
THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR
CONFIDENTIAL TREATMENT].

4      AIRCRAFT CONFIGURATION

4.1    The guarantees contained in this  Attachment are based on
the Aircraft configuration as defined in Revision A of Detail
Specification [*CONFIDENTIAL MATERIAL OMITTED AND FILED
SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT
TO A REQUEST FOR CONFIDENTIAL TREATMENT] (hereinafter referred to
as the Detail Specification).  Appropriate adjustment shall be
made for changes in such Detail Specification approved by the
Customer and Boeing or otherwise allowed by the Purchase
Agreement which cause changes to the flight performance and/or
weight and balance of the Aircraft.  Such adjustment shall be
accounted for by Boeing in its evidence of compliance with the
guarantees.

4.2     The guarantee payload of Paragraph 2.1.1 will be adjusted
by Boeing for the effect of the following on OEW and the
Manufacturer's Empty Weight guarantee of Section 3 will be
adjusted by Boeing for the following in its evidence of
compliance with the guarantees:

        (1)     Changes to the Detail Specification including
Change Requests, Change Orders, Optional Features or any other
changes mutually agreed upon between the Customer and Boeing or
otherwise allowed by the Purchase Agreement.

        (2)     The difference between the component weight
allowances given in Appendix IV of the Detail Specification and
the actual weights.

5       GUARANTEE CONDITIONS

5.1     All guaranteed performance data are based on the ICAO
International Standard Atmosphere (ISA) and specified variations
therefrom; altitudes are pressure altitudes.

5.2     The FAA Regulations (FAR) referred to in this Attachment
are, unless otherwise specified, the 777-200 Certification Basis
regulations specified in the Type Certificate Data Sheet
T-00001SE, Revision 4, dated April 18, 1996.


P.A. No. 1663
AERO-B-B111-M98-0520                                    SS98-0403


Attachment to Letter Agreement
No. 6-1162-RCN-925
PW4090 Engines
Page 10

5.3     In the event a change is made to any law, governmental
regulation or requirement, or in the interpretation of any such
law, governmental regulation or requirement that affects the
certification basis for the Aircraft as described in Paragraph
5.2, and as a result thereof, a change is made to the
configuration and/or the performance of the Aircraft in order to
obtain certification, the guarantees set forth in this Attachment
shall be appropriately modified to reflect any such change.

5.4     The takeoff portion of the mission guarantee is based on
hard surface, level and dry runway with no wind or obstacles, no
clearway or stopway, 235 mph tires, with anti-skid operative, and
with the Aircraft center of gravity at the most forward limit
unless otherwise specified.  The takeoff performance is based on
no engine bleed for air conditioning or thermal anti-icing and
the Auxiliary Power Unit(APU) turned off unless otherwise
specified.  Unbalanced field length calculations and the improved
climb performance procedure will be used for takeoff as required.

5.5     The climb, cruise and descent portions of the mission
guarantee include allowances for normal power extraction and
engine bleed for normal operation of the air conditioning system.
Normal electrical power extraction shall be defined as not less
than a 212 kilowatts total electrical load.  Normal operation of
the air conditioning system shall be defined as pack switches in
the "Auto" position, the temperature control switches in the
"Auto" position that results in a nominal cabin temperature of
75 degrees Fahrenheit, and all air conditioning systems operating 
normally.  This operation allows a maximum cabin pressure differential 
of 8.6 pounds per square inch at higher altitudes, with a nominal
Aircraft cabin ventilation rate of 7,600 cubic feet per minute
including passenger cabin recirculation (nominal recirculation is
50 percent).  The APU is turned off unless otherwise specified.

5.6     The climb, cruise and descent portions of the mission
guarantee are based on an Aircraft center of gravity location as
determined by Boeing, not to be aft of 30 percent of the mean
aerodynamic chord.

5.7     Performance, where applicable, is based on a fuel Lower
Heating Value (LHV) of 18,580 BTU per pound and a fuel density of
6.70 pounds per U.S. gallon.

P.A. No. 1663
AERO-B-B111-M98-0520                                   SS98-0403


Attachment to Letter Agreement
No. 6-1162-DLJ-1193
PW4077 Engines
Page 11


6       GUARANTEE COMPLIANCE

6.1     Compliance with the guarantees of Sections 2 and 3 shall
be based on the conditions specified in those sections, the
Aircraft configuration of Section 4 and the guarantee conditions
of Section 5.

6.2     Compliance with the takeoff portion of the mission
guarantee shall be based on the FAA approved Airplane Flight
Manual for the Model 777-200.

6.3     Compliance with the climb, cruise and descent portions of
the mission guarantee shall be established by calculations based
on flight test data obtained from an aircraft in a configuration
similar to that defined by the Detail Specification.

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

6.5     Compliance with the Manufacturer's Empty Weight guarantee
shall be based on information in the "Weight and Balance Control
and Loading Manual - Aircraft Report."

6.6     The data derived from tests shall be adjusted as required
by conventional methods of correction, interpolation or
extrapolation in accordance with established engineering
practices to show compliance with these guarantees.

6.7     Compliance shall be based on the performance of the
airframe and engines in combination, and shall not be contingent
on the engine meeting its manufacturer's performance
specification.

7       EXCLUSIVE GUARANTEES

        The only performance guarantees applicable to the
Aircraft are those set forth in this Attachment.


P.A. No. 1663
AERO-B-B111-M98-0520                                  SS98-0403