Exhibit 10.12

6-1162-ELP-0781

United Air Lines, Inc.

P. O. Box 66100

Chicago, IL
60601-0100



|           |  |                                                                                                                                                             
|---------- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------
|Subject:   |  | Additional Special Matters                                                                                                                                  
|           | 
|Reference: |  | Purchase Agreement No. 3427 (Purchase Agreement) between The Boeing Company (Boeing) and United Air Lines, Inc. (Customer) relating to Model 787-8
aircraft.

This letter agreement (Letter Agreement) amends and supplements the Purchase Agreement. All capitalized terms used but
not defined in this Letter Agreement have the same meaning as in the Purchase Agreement.

1. [CONFIDENTIAL MATERIAL OMITTED AND FILED
SEPARATELY WITH THE SEC PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]

2. [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH
THE SEC PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]

3. Notice of [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH
THE SEC PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]

3.1 Should Customer elect to [CONFIDENTIAL MATERIAL OMITTED
AND FILED SEPARATELY WITH THE SEC PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]

4. [CONFIDENTIAL MATERIAL OMITTED AND FILED
SEPARATELY WITH THE SEC PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]

5. [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH
THE SEC PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT].

6. Alternative to [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH
THE SEC PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]



P.A. No.

Additional Special Matters

BOEING / UNITED PROPRIETARY



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United Air Lines, Inc.

6-1162-ELP-0781



As an alternative to [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE
SEC PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]in accordance with terms and conditions described in paragraph 3, in conjunction with the [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SEC PURSUANT TO A REQUEST FOR
CONFIDENTIAL TREATMENT].

7. Applicability of Certain Terms and Conditions.

[CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SEC PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]

8 [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SEC PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]

9 [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SEC PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]

10. Assignment.

The
rights and obligations described in this Letter Agreement are provided to Customer in consideration of Customer becoming the operator of the Aircraft and can only be assigned, in whole or in part, pursuant to Article 9 of the AGTA as amended by
Letter Agreement No. 6-1162-IRS-0184.

11. [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SEC PURSUANT TO A REQUEST FOR
CONFIDENTIAL TREATMENT]



P.A. No. 3427

Additional Special Matters

BOEING / UNITED PROPRIETARY



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United Air Lines, Inc.

6-1162-ELP-0781



12 Confidential Treatment.

Customer and Boeing understand that certain commercial and financial information contained in this Letter Agreement are considered by
Boeing and Customer as confidential and are subject to the terms and conditions set forth in Letter Agreement No. 6-1162-IRS-0182.



|                            |  |                 
|--------------------------- |  | ----------------
|Very truly yours,          
|                           
|THE BOEING COMPANY         
|                            | 
|By                          |  | /s/ Nobuko Wiles
|                            | 
|Its                         |  | Attorney-In-Fact
|                           
|ACCEPTED AND AGREED TO this
|                           
|Date: February 19, 2010    
|                           
|UNITED AIR LINES, INC.     

|    |  |                                                     
|--- |  | ----------------------------------------------------
|    | 
|By  |  | /s/ Kathryn A. Mikells                              
|    | 
|Its |  | Executive Vice President and Chief Financial Officer



P.A. No. 3427

Additional Special Matters

BOEING / UNITED PROPRIETARY



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Attachment A to

6-1162-ELP-0781



[CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SEC

PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]



P.A. No.

Additional Special Matters

BOEING / UNITED PROPRIETARY