Exhibit 10.18.3

CCR Modification Agreement Certification

This CCR Modification Agreement is entered into by the parties hereto in connection with the Loan and Guarantee Agreement dated as of October 30, 2020, and entered into pursuant to Division A, Title IV, Subtitle A, section 4029 of the Coronavirus Aid, Relief, and Economic Security Act (P. L. 116-136), as amended. The parties named below and their undersigned authorized representatives acknowledge that a materially false, fictitious, or fraudulent statement (or concealment or omission of a material fact) in connection with this CCR Modification Agreement may result in administrative remedies as well as civil and/or criminal penalties.

Exhibit 10.18.3

CCR MODIFICATION AGREEMENT

Dated December 23, 2024

Reference is made to (1) that certain Loan and Guarantee Agreement dated as of October 30, 2020 (the “Loan Agreement”), among MESA AIRLINES, INC., a corporation organized under the laws of Nevada (the “Borrower”), MESA AIR GROUP, INC., a corporation organized under the laws of Nevada (the “Parent”), the Guarantors party thereto from time to time, the UNITED STATES DEPARTMENT OF THE TREASURY (“Treasury”), and THE BANK OF NEW YORK MELLON as Administrative Agent and Collateral Agent, as modified by the Modification and Waiver Agreement (as defined below); (2) the Pledge and Security Agreement dated as of October 30, 2020 (the “Pledge Agreement”), among the Grantors thereto and the Collateral Agent, as amended by that certain First Amendment to the Pledge and Security Agreement, dated as of February 11, 2022, and as supplemented by that certain Pledge Supplement, dated as of November 13, 2020 (the “Pledge Supplement”), among the Grantors and the Collateral Agent; (3) the Modification and Waiver Agreement (“Modification and Waiver Agreement”) dated as of December 22, 2022, among the Borrower, the Parent, the Guarantors party thereto, Treasury, the Administrative Agent and the Collateral Agent; and (4) the CCR Modification Agreement dated as of September 23, 2024 (“September 2024 CCR Modification Agreement”). Capitalized terms used in this CCR Modification Agreement (this “Agreement”) but not otherwise defined shall have the meanings given to such terms in the Loan Agreement and the Pledge Agreement, as applicable.

WHEREAS, pursuant to Section 5.19(b) of the Loan Agreement (the “CCR Eligible Receivables Requirement”), if the Collateral Coverage Ratio as of any CCR Reference Date is less than 1.60 to 1.00, then all amounts on deposit in the Eligible Receivables Account or transferred thereto shall be required to be held in such Eligible Receivables Account uninvested, and the Parent and the Subsidiaries shall not transfer any funds from such Eligible Receivables Account (except for the application to prepay the Loans then outstanding in accordance with Section 2.06(a) of the Loan Agreement) until the first CCR Reference Date on which the Collateral Coverage Ratio is 1.60 to 1.00 or more, whereupon funds may once again be transferred from the Eligible Receivables Account for purposes other than prepayment of the Loans;

WHEREAS, pursuant to Section 6.17(b)(ii) of the Loan Agreement (the “CCR Covenant”), the Borrower covenanted to, in the event that the Collateral Coverage Ratio with respect to any CCR Reference Date is less than 1.60 to 1.00, prepay any outstanding Loans and/or designate Additional Collateral as additional Eligible Collateral, collectively, in an amount such that following such prepayment and/or designation, the Collateral Coverage Ratio with respect to such CCR Reference Date, recalculated as appropriate, shall be no less than 1.60 to 1.00;

WHEREAS, pursuant to Section 2 of the Modification and Waiver Agreement, the Administrative Agent, on behalf of the Lenders and at the direction of the Required Lenders, agreed to modify both the CCR Eligible Receivables Requirement and the CCR Covenant with a Collateral Coverage Ratio of 1.55 to 1.00, effective as of October 1, 2022 through the Maturity Date;

Exhibit 10.18.3

WHEREAS, pursuant to Section 1 and Section 2 of the September 2024 CCR Modification Agreement, the Administrative Agent, on behalf of the Lenders and at the direction of the Required Lenders, agreed to modify both the CCR Eligible Receivables Requirement and the CCR Covenant with a Collateral Coverage Ratio of 1.44 to 1.00, effective as of September 23, 2024 through November 22, 2024;

WHEREAS, the Parent requested that the Collateral Coverage Ratio in the CCR Eligible Receivables Requirement and the CCR Covenant be reduced from 1.55 to 1.00 to 0.99 to 1.00 until February 28, 2025;

WHEREAS, the Administrative Agent, on behalf of the Lenders (as defined in the Loan Agreement) and at the direction of Treasury, in its capacity as the Required Lenders (as defined in the Loan Agreement), has agreed to modify the CCR Covenant as set forth herein, and Treasury, in its capacity as the Required Lenders, has consented to such modification of the CCR Eligible Receivables Requirement and the CCR Covenant;

NOW, THEREFORE, in consideration of the mutual promises contained herein and other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereto agree as follows:

“The Credit Parties shall instruct and use their reasonable best efforts to cause counterparties to all Receivables (whether or not constituting “Eligible Receivables”) to direct payments of all amounts required to be paid to the Credit Parties (and their Affiliates), and all other amounts the Credit Parties are entitled to, under any such Receivable to the Eligible Receivables Account, provided, however, that Receivables generated from the sale, by any Credit Party, of assets that are not Collateral shall be excluded from the scope of this provision.”

Exhibit 10.18.3

[Signature Pages to Follow.]

Exhibit 10.18.3

IN WITNESS WHEREOF, the Borrower, each Guarantor, the Administrative Agent, the Collateral Agent, and Treasury have caused this Agreement to be duly executed and delivered by their respective officers thereunto duly authorized as of the date first written above.

[Signature Page to the CCR Modification Agreement – Mesa Airlines, Inc.]

Exhibit 10.18.3

[Signature Page to the CCR Modification Agreement – Mesa Airlines, Inc.]

Exhibit 10.18.3

[Signature Page to the CCR Modification Agreement – Mesa Airlines, Inc.]