Supplemental Agreement No. 13 to Purchase Agreement No. 03776, dated as of March 20, 2020, between The Boeing Company and United Airlines, Inc

THIS SUPPLEMENTAL AGREEMENT, entered into as of March 20, 2020, by and between THE BOEING COMPANY (Boeing) and UNITED AIRLINES, INC. (Customer) (SA-13);

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 *** 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 regarding the following matters without duplication of any consideration being provided to Customer:

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

1.Letter Agreement No. UAL-PA-03776-LA-1207637R1 is deleted in its entirety and replaced with Letter Agreement UAL-PA-03776-LA-1207637R2 entitled "*** Matters" to provide Customer with certain ***.

2.Letter Agreement No. UAL-PA-03776-LA-1208596R1 is deleted in its entirety and replaced with the attached Letter Agreement UAL-PA-03776-LA-1208596R2 entitled "AGTA Matters" (identified by SA-13) to revise warranty provisions.

3.Letter Agreement No. UAL-PA-03776-LA-1208869 is deleted in its entirety and replaced with Letter Agreement UAL-PA-03776-LA-1208869R1 entitled "Delivery *** Matters" to provide additional *** rights.

4.Letter Agreement No. UAL-PA-03776-LA ###-###-#### entitled "Certain Special Matters" is added to the Purchase Agreement to specify consideration applicable to certain Boeing aircraft.

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

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 UCH-PA-03776-LA-1207646R1 dated June 7, 2017.

The Purchase Agreement incorporates the terms and conditions of AGTA/UAL between Boeing and Customer. This Letter Agreement modifies certain terms and conditions of the AGTA with respect to the Aircraft.

1.***.

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.

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.

If the foregoing correctly sets forth your understanding of our agreement with respect to the matters treated above, please indicate your acceptance and approval below.

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

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 replaces in its entirety Letter Agreement UAL-PA-03776-1208596R1 dated May 15, 2018.

1.AGTA Basic Articles.

1.1Article 2.1.1, "Airframe Price," of the basic articles of the AGTA is revised to read as follows:

Airframe Price is defined as the price of the airframe for a specific model of aircraft described in a purchase agreement. (For Models 737-600, 737-700, 737-800, 737-900, 737-7, 737-8, 737-9, 737-10, 747-8, 777-

1.2Article 2.1.3, "Engine Price" of the basic articles of the AGTA is revised to read as follows:

Engine Price is defined as the price set by the engine manufacturer for a specific engine to be installed on the model of aircraft described in a purchase agreement (*** to Models 737-600, 737-700, 737-800,

1.3Article 2.1.5, "*** Adjustment" of the basic articles of the AGTA is revised to read as follows:

*** Adjustment is defined as the price adjustment to the Airframe Price (*** for Models 737-600, 737-700 737-800, 737-900, 737-7, 737-8, 737-9, 737-10, 747-8, 777-200LR and 777-300ER) and the *** Features Prices resulting from the calculation using the economic price formula contained in *** to the ***. The price adjustment to the Engine Price for all other models of aircraft will be calculated using the ***.

Article 11. Notices.

All notices required by this AGTA or by any applicable purchase agreement will be written in English, will be effective on the date of receipt, and will be delivered or transmitted by any customary means to the appropriate address or number listed below:

(iv) For the Delivered Aircraft, Boeing will *** of the standard Boeing Products Warranty *** by the FAA ***. Delivered Aircraft is defined as the *** Aircraft over which Customer has taken delivery as of ***.

2.1Appendix I, entitled "SAMPLE Insurance Certificate" the Combined Single Limit Bodily Injury and Property Damage: U.S. Dollars ($) any one occurrence each Aircraft (with aggregates as applicable) is added for the 737-7, 737-8, 737-9 and 737-10 in the amount of ***.

3.1Part 2, Article 3.1, subsection (i), of Exhibit C of the AGTA is revised to read as follows:

737-800, 737-900, 737-7, 737-8, 737-9, 737-10, 787 or new aircraft models designed and manufactured with similar, new technology and for the model 747-8, the warranty period ends *** months after Delivery.

Reference: Purchase Agreement No. PA-03776 (Purchase Agreement) between The Boeing Company (Boeing) and United Continental Holdings, Inc. (Customer) relating to Model 737-9 aircraft (Aircraft)

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 replaces in its entirety Letter Agreement UAL-PA-03776-1208869 dated July 12, 2012.

1.Delivery ***. *** has requested, and *** has agreed to provide, *** in the *** of ***. *** will provide *** subject to the following terms and conditions:

1.1Such *** is offered to *** subject to available ***.

1.2Such *** may *** for a period of no greater than ***.

1.3*** will be available for Aircraft deliveries in ***, and will be limited to no more than ***.

1.4*** must exercise the *** by providing *** with written notification at least *** months prior to the first day of *** or *** of the Aircraft for which the *** is requested.

2.Reciprocal ***. Should *** successfully exercise its *** pursuant to the terms of this Letter Agreement, *** will be provided with a *** subject to the following terms and conditions:

2.1Such *** may *** for a period of no greater than ***.

2.2*** will be provided with *** after every *** successfully exercised ***. Unless exercised pursuant to the terms and conditions of this Letter Agreement, each *** will terminate *** months from the first day of the month that such *** is made available to ***.

2.3*** must exercise each *** by providing *** with written notification at least *** months prior to the first day of the *** or *** of the Aircraft for which the *** will be applied to.

3.1*** has requested and *** has agreed to provide *** in the form of a *** of any of the *** subject to compliance with the following terms:

3.2*** will provide written notice to *** no later than *** days prior to the first day of the *** of a *** for which the *** is requested (each and collectively a ***);

3.3The parties agree to work together to determine a mutually agreeable *** for all *** such that applicable ***;

3.4*** agrees to provide *** with written notice of the *** for any *** no later than *** days prior to the first day of such *** for any ***;

3.5*** will not *** in respect of a *** earlier than at *** of the corresponding ***;

3.6    For the purpose of this Article 3, *** is defined as each of the *** scheduled for *** in *** in the Purchase Agreement.

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.

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.

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

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.

1.Customer Business Consideration.

(a)    *** in the *** at time of delivery of each of the *** 737-*** Aircraft *** in the Purchase Agreement (***), for ***.

1.2If by ***, Boeing has ***, then Boeing will *** under the terms of paragraph 1.1 above, by ***; provided, however, that *** (as that term is defined in Section 3.1 of Letter Agreement UAL-PA-03776-LA-1208869R1) shall be ***.

(i) the *** of *** and *** provided by Boeing and/or its affiliates, and/or (ii) the *** by Boeing to Customer. Customer may *** to ***.

The parties agree that Boeing has the *** of the *** in respect of any of the *** in accordance with the following terms:

2.***.

The calculation of the *** for each *** and each *** will be based on the *** specified in the Purchase Agreement.

3.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.

4.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