CONFIDENTIAL MATERIAL APPEARING IN THIS DOCUMENT HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION INACCORDANCE WITH THE SECURITIES ACT OF 1933, AS AMENDED, AND RULE 24B-2 PROMULGATED THEREUNDER. OMITTED INFORMATION HAS BEEN REPLACED WITH ASTERISKS. Supplemental Agreement No. 2 to Purchase AgreementNo. 03776 between TheBoeing Company and UnitedAirlines, Inc. Relating to Boeing Model 737-9 Aircraft

Exhibit 10.5

CONFIDENTIAL MATERIAL APPEARING IN THIS DOCUMENT HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION IN ACCORDANCE WITH THE SECURITIES ACT OF 1933, AS AMENDED, AND RULE 24B-2 PROMULGATED THEREUNDER. OMITTED INFORMATION HAS BEEN REPLACED WITH ASTERISKS.

Supplemental Agreement No. 2

to

Purchase Agreement No. 03776

between

The Boeing Company

and

United Airlines, Inc.

Relating to Boeing Model 737-9 Aircraft

THIS SUPPLEMENTAL AGREEMENT, entered into as of January 14, 2015, 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. 03776 dated July 12, 2012, as amended and supplemented (Purchase Agreement), relating to the purchase and sale of Boeing model 737-9 aircraft (Aircraft). This Supplemental Agreement is an amendment to the Purchase Agreement;

WHEREAS, Boeing and Customer agree to *** the following *** model 737-*** aircraft (*** Aircraft) in lieu of *** model 737-*** aircraft (*** Aircraft) pursuant to Supplemental Agreement No. 62 to Purchase Agreement No. 1951:

WHEREAS, Boeing and Customer agree to *** the following *** model 737-*** Option Aircraft ( *** Options):

Supplemental Agreement No. 2 to

Purchase Agreement No. 03776

WHEREAS, Boeing and Customer agree to *** received by Boeing for the *** Aircraft and the *** Options to the *** Aircraft.

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

1. Table of Contents and Articles.

The Table of Contents, is replaced in its entirety with the Table of Contents that is attached hereto and references this Supplemental Agreement No. 2.

2. Tables.

Table 1 is removed and replaced, in its entirety, with the Table 1 that is attached hereto and references this Supplemental Agreement No. 2.

3. Letter Agreements.

Attachment A to UCH-PA-03776-LA-1207644 is replaced in its entirety with the Attachment A to UCH-PA-03776-LA-1207644 that is attached hereto and references this Supplemental Agreement No. 2.

4. Conditions Precedent: This Supplemental Agreement No. 2 will be effective subject to satisfaction of all of the following conditions precedent (collectively the Conditions Precedent):

Upon satisfaction of the Conditions Precedent, the Purchase Agreement will be deemed to be supplemented to the extent herein provided as of the date hereof and as so supplemented will continue in full force and effect.

Supplemental Agreement No. 2 to

Purchase Agreement No. 03776

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

TABLE OF CONTENTS

TABLE OF CONTENTS, CONTINUED

Table 1 To

Purchase Agreement No. 03776

737-9 Aircraft Delivery, Description, Price and Advance Payments

Table 1 To

Purchase Agreement No. 03776

737-9 Aircraft Delivery, Description, Price and Advance Payments

Table 1 To

Purchase Agreement No. 03776

737-9 Aircraft Delivery, Description, Price and Advance Payments

Table 1 To

Purchase Agreement No. 03776

737-9 Aircraft Delivery, Description, Price and Advance Payments

Table 1 To

Purchase Agreement No. 03776

737-9 Aircraft Delivery, Description, Price and Advance Payments

Table 1 To

Purchase Agreement No. 03776

737-9 Aircraft Delivery, Description, Price and Advance Payments

* Nominal delivery month, *** pursuant to Letter Agreement number UCH-PA-03776-LA-1207643.

Note: The estimated Advance Payment Base Prices have been calculated using a *** , and *** , as follows:

Attachment A to Letter Agreement No. UCH-PA-03776-LA-1207644

737-9 Option Aircraft Delivery, Description, Price and Advance Payments

Note: The estimated Advance Payment Base Prices have been calculated using a ***: