ual_2023093010qex1020

Exhibit 10.20 CERTAIN IDENTIFIED INFORMATION HAS BEEN EXCLUDED FROM THE EXHIBIT BECAUSE IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. OMITTED INFORMATION HAS BEEN REPLACED WITH ASTERISKS. Supplemental Agreement No. 2 to Purchase Agreement No. 3860 between The Boeing Company and United Airlines, Inc. Relating to Boeing Model 787 Aircraft THIS SUPPLEMENTAL AGREEMENT, entered into as of December 16, 2013, by and between THE BOEING COMPANY (Boeing) and UNITED AIRLINES, INC. (a Delaware corporation formerly known as Continental Airlines, Inc. and successor by merger to United Air Lines, Inc.) (Customer); WHEREAS, the parties hereto entered into Purchase Agreement No. 3860 dated September 27, 2012, as amended and supplemented (Purchase Agreement), relating to the purchase and sale of Boeing Model 787 aircraft (Aircraft). This Supplemental Agreement is an amendment to the Purchase Agreement; WHEREAS, Boeing and Customer agree to substitute *** Model 787-*** aircraft (787-*** Aircraft) in lieu of Model 787-*** aircraft (787-*** Aircraft) and to revise the scheduled delivery for these Aircraft as follows: 787-*** Aircraft 787-*** Aircraft Manufacturer Serial Number Delivery Month Delivery Month *** *** *** *** *** *** *** WHEREAS, Boeing and Customer have previously agreed to accelerate the promotional support funds for the Aircraft so that such promotional support funds were made available Customer on ***; and WHEREAS, Customer has agreed to configure the Aircraft with engines provided by General Electric; UAL-PA-3860 SA-2, Page 1 BOEING / UNITED AIRLINES, INC. PROPRIETARY � !" #$ " % &#$ '#$ (�") ")" #")"!"#! %#! (*+,+-, ")")"#! %#! (*+,+-. ")"/"#! %#! (*+,+-!0 "/" 1 % 121--0/,30-1-!)0.4!3&('121--0/,30-1-!)0.4!3! " ##5 " 6%#7"("821--/,30 (-) )9:;<=>?@=<A;BC<DE<=;FG<=HIJD:JD<;ACDK �� !"#$%!&'(#) *#"+(",-"#./"#%0112 3 114 5 6 78 9 78 9::; < 7=< >; <? <96 95 5: :@ABC 7:D? 8@ !"#$E*#"+(",-"#./"#%0',!',"(,) � � �� !!"#$ %&' "(%)! %&* + %&, +- %&. !! /-# %&� 01 2324356789 :40;;;<=6<>?6@A@BC7 <CD@EB76D<�BFG> 4H01 2324I56789 :40;;;<=6<>?6@A@BC7 <CD@EB76D<�BFG> 4H01 23240J56789 :40;;;<=6<>?6@A@BC7 <CD@EB76D<�BFG> 4H:K � LML&MNO NP ' LML&QNO NP * LML&RNO NP %&S N"(TU-#!T#$ #V# WW �:K � X X# !Y#-ZN-![$ \# S\X S\X]V# %&O% O# -%$$ " - XX XPX# ZXP̂;;; %_+ %(_N+ O -$ # ��9 � ̀_&+&R*MaR&_&'RQ',L LML&XVP ̀_&+&R*MaR&_&'RQ'a, [$O NP # +*MaR /S_X[\O[b/Xb/%+P N* %& 9c �d e 1WW �f

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