Letter Agreement WJE-PA-05130-LA-2101482R2 by and between The Boeing Company and Allegiant Air, LLC dated November 14, 2024

Reference: Purchase Agreement No. PA-05130 (Purchase Agreement) between The Boeing Company (Boeing) and Allegiant Air, LLC (Customer) relating to Model 737-8-200 and Model 737-7 aircraft (Aircraft)

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

1.Definition of Terms.

[***]

2.[***]

3.[***]

[***]

4.[***]

[***]

4.1[***]

4.2[***]

5.[***]

[***]

5.1[***]

5.2[***]

5.3[***]

6.[***]

6.1[***]

6.2[***]

6.3[***]

6.4[***].

6.5[***]

7.[***]

[***]

(i)[***]

(ii)[***]

(iii)[***]

8.[***].

[***]

9.[***]

[***].

10.Confidentiality.

The information contained herein represents confidential business information and has value precisely because it is not available generally or to other parties. Customer will limit the disclosure of its contents to (i) Customer and Customer affiliates’ employees, officers and directors and (ii) Customer and Customer affiliates’ legal counsel, professional advisors and auditors subject to a duty of confidence or a non- disclosure undertaking, in each case with a need to know the contents for purposes of helping Customer perform its obligations under the Purchase Agreement and who understand they are not to disclose its contents to any other person or entity without the prior written consent of Boeing unless disclosure is required by applicable law or court order, in which case, Customer shall (i) notify Boeing in writing of such disclosure requirement or request prior to making such disclosure, and will take steps to protect the information contained herein, and (ii) use reasonable efforts to obtain redaction and confidential treatment for the disclosed information or parts thereof.