Supplemental Agreement No. 21 to Purchase Agreement No. 03776, dated as of December 15, 2023, between The Boeing Company and United Airlines, Inc

THIS SUPPLEMENTAL AGREEMENT, entered into as of December 15, 2023, by and between THE BOEING COMPANY (Boeing) and UNITED AIRLINES, INC. (Customer) (SA-21);

WHEREAS, the parties hereto entered into Purchase Agreement No. 3776 dated July 12, 2012, as amended and supplemented (Purchase Agreement), relating to the purchase and sale of Boeing model 737 MAX aircraft (Aircraft). This Supplemental Agreement is an amendment to the Purchase Agreement;

WHEREAS, solely to conform and further amend the Purchase Agreement to reflect Customer and Boeing’s agreement to *** the following Aircraft:

WHEREAS, solely to conform and further amend the Purchase Agreement to reflect Customer and Boeing’s agreement to *** the following Aircraft including deletion of Table 1C since the *** quantity of 737-*** configuration is no longer applicable (due to the *** below):

WHEREAS, solely to conform and further amend the Purchase Agreement to reflect Customer and Boeing’s agreement regarding the following matters without duplication of any consideration being provided to Customer to:

(i)*** the estimate of *** features included in the *** configuration of 737-*** Aircraft;

(ii)*** certain open configuration matters for the Aircraft;

(iii)Conform the Purchase Agreement to incorporate the Aircraft *** above including the *** considerations associated with such ***; and

(iv)*** certain of the terms of the *** in respect of possible 737-10 Aircraft ***.

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

The “Table of Contents” is deleted in its entirety and replaced with the attached “Table of Contents” (identified by “SA-21”).

2.1.Table 1.1 entitled “*** 737-*** Aircraft Delivery, Description, Price and ***” is deleted in its entirety and replaced with the attached similarly titled Table 1.1 (identified by “SA-21”) to reflect *** additional 737-*** as a result of *** from (i)  *** 737-*** Aircraft in a *** configuration and (ii) *** 737-*** Aircraft in a *** configuration.

2.2.Table 1A entitled “737-10 *** Aircraft Delivery, Description, Price and ***” is deleted in its entirety and replaced with the attached similarly titled Table 1A (identified by “SA-21”) to reflect the *** in the quantity of 737-*** Aircraft due to *** into *** 737-*** Aircraft.

2.3.Table 1B entitled “*** 737-*** Aircraft Delivery, Description, Price and ***” is deleted in its entirety and replaced with the attached similarly titled Table 1B (identified by “SA-21”) to reflect the *** in the quantity of 737-*** Aircraft due to substitution into *** 737-*** Aircraft.

2.4.Exhibit A-5 entitled “737-*** Aircraft Configuration” is deleted in its entirety and replaced with the attached similarly titled Exhibit A-5 (identified by “SA-21”) to reflect the updated estimate of the *** features of 737-*** Aircraft in a *** configuration.

3.1.Letter Agreement No. UAL-PA-03776-LA-1207650R6 is deleted in its entirety and replaced with Letter Agreement No. UAL-PA-03776-LA-1207650R7 titled “Special Matters” to incorporate *** consideration applicable to the *** 737-*** Aircraft.

3.2.Letter Agreement No. UAL-PA-3776-LA ###-###-#### is deleted in its entirety and replaced with Letter Agreement No. UAL-PA-3776-LA-2103288R1 titled “***” to revise certain terms therein.

Boeing and Customer agree to work together to (i) consider administrative clarification revisions to the five (5) letter agreements listed in the table below; and (ii) provide equivalent rights, benefits and obligations between the parties as established under 737 purchase agreement number 4761 (MAX Purchase Agreement #2), including any subsequent modifications agreed to by the parties pursuant to Section 4.2 of supplemental agreement number 13 to MAX Purchase Agreement #2. The parties will work towards completing such discussions by February 29, 2024. If applicable, a supplemental agreement, to effect any mutually agreed revisions of the applicable letter agreements, will be prepared to amend the Purchase Agreement.

The Detail Specification is Boeing document number *** dated May ***. The estimate for *** features was estimated using Customer’s guidance as seen in Attachment 1 to this Exhibit A. Such Attachment 1 estimate of *** features comprises Customer’s Initial Configuration which is *** pursuant to the provisions of Letter Agreement UAL-PA-03776-LA-1207643R4 entitled “Open Matters 737-*** Aircraft”

Subject:    Special Matters – 737 MAX Aircraft

References:    1)    Purchase Agreement No. PA-03776 (Purchase Agreement) between The Boeing Company (Boeing) and United Airlines, Inc. (Customer) relating to Model 737 MAX aircraft (Aircraft); and

2)    Letter Agreement UAL-PA-03776-1207638 entitled ***

This letter agreement (Letter Agreement) amends and supplements the Purchase Agreement. All terms used but not defined in this Letter Agreement shall have the same meaning as in the Purchase Agreement. This Letter Agreement supersedes and replaces in its entirety Letter Agreement UAL-PA-0 3776-LA-1207650R6 dated November 30, 2021.

1.***.

1.1***. At the *** of each 737-*** Aircraft, Boeing ***.

1.5 *** Aircraft ***.

The parties agree to the following *** Boeing Model 737-*** aircraft specified in Table 1 and Table 1.1; *** Boeing Model 737-*** aircraft specified in Table 1A, and (iii) the *** Boeing Model 737-*** aircraft specified in Table 1B at the effective date of this Letter Agreement and as may be subsequently ***. The *** aircraft comprise the *** Aircraft.

1.5.1 At the time of *** of each applicable *** Aircraft, Boeing ***.

1.5.2 Boeing and Customer will work together to periodically assess and agree to determine whether and how *** established in Attachment 1 *** provided in Attachment 2 to this Letter Agreement. Such assessment will incorporate the methodology and .assumptions incorporated in development of Attachment 1 to this Letter Agreement including *** to the effective date of Supplemental Agreement No. 7 to the 787 Purchase Agreement No. 3860 and *** in Attachment 1 to this Letter Agreement.

1.6 737-***.

***

1.7 *** 737 ***.

***

1.8 ***.

1.9 *** 737 ***.

***

* - in *** Dollars, ***

1.10 Special Provisions for Certain 737-***. Customer has requested assurances from Boeing on the timing of issuance of the amended type certification for the 737-*** aircraft from the FAA (737-*** ATC) to support availability of the “***” configuration for delivery of all of Customer’s 737-*** Aircraft and 737-*** aircraft in *** configuration. In response to Customer’s requests for assurances, Boeing has revised its expectations regarding the timing within which the 737-*** ATC for the 737-*** Aircraft will be received. As a result of the provision of Boeing guidance referred to in this Section 1.10, Customer and Boeing agree to ***.

1.10.1 At the time of delivery of each 737-*** Aircraft specified in Attachment 3 that will be purchased by Customer in lieu of any 737-*** Aircraft, Boeing will issue to Customer *** in the amounts specified in the table below (*** 737-***). The *** 737-*** may, at the election of Customer, be ***.

1.10.2 At the time of delivery of each 737-*** Aircraft specified in Attachment 3 that will be purchased by Customer in lieu of any 737-*** Aircraft, Boeing will issue to Customer *** in the amounts specified in the table below (*** 737-***). The *** 737-*** may, at the election of Customer, be ***.

2.***.

Unless otherwise noted, the *** stated in Sections 1.1 through 1.10 (***) are in (a) *** dollars for the 737-*** Aircraft, the 737-*** Aircraft, the 737-*** Aircraft, and for each 737-*** and 737-*** Aircraft specified in Attachment 3; and (b) *** dollars for 737-*** Aircraft. The *** will be *** to the scheduled month of the respective Aircraft *** pursuant to the *** formula set forth in the Purchase Agreement applicable to the Aircraft. The *** may, at the election of Customer, be *** Boeing *** and *** (but shall ***).

3.Reserved.

4.737 Supplier Management.

It is Boeing’s 737 *** design intent to maintain as much commonality with the 737NG while also achieving the 737 *** performance requirements (including, but not limited to, ***, etc.) that the market demands. If a *** leads to a Supplier Product to be available *** for the 737 *** where *** on the 737NG, or if an existing 737NG ***, then Boeing will ensure that *** 737 *** operators ***. These *** agreements, known as ***, will include (but not be limited to) enforceable provisions related to ***. Boeing will utilize *** efforts to ensure that the terms of such *** agreements are ***.

5.Supplier Diversity.

Customer and Boeing agree to work towards a mutually agreeable solution for meeting diversity requirements in the supply base. Notwithstanding the foregoing sentence, Boeing agrees to (i) identify parts and equipment where Customer makes the procurement decision for potential opportunities; (ii) submit indirect reports until other options are vetted and approved; and (iii) continue to engage with Customer with regard to supplier diversity to ensure Boeing supports Customer’s requirements.

6.Delivery ***.

Customer and Boeing agree that both Customer and Boeing will have certain Aircraft ***. Such *** are provided to Customer and Boeing pursuant to Letter Agreement No. UAL-PA-03776-LA-1208869.

7.Assignment.

Unless otherwise noted herein, the *** described in this Letter Agreement are provided as *** to Customer and in consideration of ***. Except as provided in Letter Agreement No. UAL-PA-03776-LA-1208238, this Letter Agreement cannot be assigned, in whole or in part, without the prior written consent of Boeing. ***.

8.Confidentiality

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. UAL-PA-03776-LA-1208234.

Subject:    ***

References:    1)    Purchase Agreement No. 03776 (Purchase Agreement) between The Boeing Company (Boeing) and United Airlines, Inc. (Customer) relating to Model 737 MAX aircraft (Aircraft), including Letter Agreement No. UAL-PA-03776-LA-1208122R1 entitled “***” (***); and Letter Agreement No. UAL-PA-03776-LA-1207650R7 entitled “Special Matters – 737 MAX Aircraft” (Special Matters Letter Agreement)

2)    Aircraft General Terms Agreement dated as of July 12, 2012 between the parties, identified as UCH-AGTA (AGTA)

This letter agreement (Letter Agreement) amends and supplements the Purchase Agreement. All terms used but not defined in this Letter Agreement shall have the same meaning as in the Purchase Agreement. This Letter Agreement supersedes and replaces in its entirety Letter Agreement UAL-PA-03776-LA ###-###-#### dated June 27, 2021

***

12.Assignment.

Except as provided in Letter Agreement No. UAL-PA-03776-LA-1208238, the rights and obligations described in this Letter Agreement are provided to Customer in consideration of Customer’s becoming the operator of the Aircraft and cannot be assigned in whole or, in part.

13.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. UAL-PA-03776-LA-1208234.