0001193125-26-228878 Sample Contracts

UNDERWRITING AGREEMENT WILLIS LEASE FINANCE CORPORATION $200,000,000 2.50% Convertible Senior Notes Due 2031 May 13, 2026
Underwriting Agreement • May 18th, 2026 • Willis Lease Finance Corp • Wholesale-machinery, equipment & supplies • New York

The information in this pricing term sheet supplements (i) Willis Lease Finance Corporation’s (“Willis”) preliminary prospectus supplement, dated May 13, 2026 (the “Common Stock Preliminary Prospectus Supplement”), relating to an offering of common stock by the underwriter in the delta offering (the “Delta Offering”), and (ii) Willis’ preliminary prospectus supplement, dated May 13, 2026 (the “Convertible Notes Preliminary Prospectus Supplement”), relating to an offering of convertible senior notes by Willis (the “Convertible Notes Offering”), and, in each case, the accompanying prospectus, dated May 15, 2025, filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended (the “Securities Act”). This pricing term sheet supersedes the information in the Common Stock Preliminary Prospectus Supplement and the Convertible Notes Preliminary Prospectus Supplement to the extent inconsistent with the information in the Common Stock Preliminary Prospectus Supplement or the Convertib

WILLIS LEASE FINANCE CORPORATION and as Trustee FIRST SUPPLEMENTAL INDENTURE Dated as of May 18, 2026
First Supplemental Indenture • May 18th, 2026 • Willis Lease Finance Corp • Wholesale-machinery, equipment & supplies • New York

This Supplemental Indenture (as defined below) is being executed and delivered pursuant to Sections 2.2 and 9.1(i) of the Base Indenture to establish the terms, and provide for the issuance, of a new series of Securities (as defined in the Base Indenture) constituting the Company’s 2.50% Convertible Senior Notes due 2031 (the “Notes”).

AMENDMENT NO. 4 to CREDIT AGREEMENT Dated as of May 13, 2026
Credit Agreement • May 18th, 2026 • Willis Lease Finance Corp • Wholesale-machinery, equipment & supplies • New York

This AMENDMENT NO. 4 TO CREDIT AGREEMENT (this “Fourth Amendment”), is entered into as of May 13, 2026, by and among WILLIS LEASE FINANCE CORPORATION, a Delaware corporation (“Borrower”), the GUARANTORS party hereto, the LENDERS party hereto and BANK OF AMERICA, N.A., in its capacity as administrative agent for the Lenders (in such capacity, the “Administrative Agent”).