Material Agreement, Proxy Statement (Form 8-K)

Membership Interest Purchase Agreement

On December 10, 2025, Harbor Diversified, Inc. (the "Company") entered into a Membership Interest Purchase Agreement (the "Membership Interest Purchase Agreement"), by and among the Company's wholly owned subsidiary, AWAC Aviation, Inc. ("AWAC"), CSI Aviation, Inc. ("CSI"), and, solely for the purposes of Section 9.19 of the Membership Interest Purchase Agreement, the Company, pursuant to which (i) AWAC agreed to sell to CSI all of its right, title and interest in and to 100% of the issued and outstanding membership interests of Air Wisconsin Airlines LLC, for a portion of the Aggregate Purchase Price (as defined below), and (ii) the Company agreed to guarantee the payment and performance of AWAC's indemnification obligations set forth in the Membership Interest Purchase Agreement.

The Company anticipates that the transactions contemplated by the Membership Interest Purchase Agreement will close promptly following the satisfaction of customary closing conditions, including receipt of required regulatory approvals, and simultaneously with the closing of the transactions contemplated by the CSI Asset Purchase Agreement and the ASL Asset Purchase Agreement (each as defined below). The Membership Interest Purchase Agreement contains representations, warranties and covenants by AWAC that are customary for transactions of this type, which were made solely for the benefit of the parties thereto.

CSI Asset Purchase Agreement

On December 10, 2025, the Company entered into an Asset Purchase Agreement with CSI (the "CSI Asset Purchase Agreement") providing for the Company's sale of 13 Bombardier model CL-600-2B19 CRJ200 aircraft and inventory of certain expendable parts to CSI for a portion of the Aggregate Purchase Price.

The Company anticipates that the transactions contemplated by the CSI Asset Purchase Agreement will close promptly following the satisfaction of customary closing conditions and simultaneously with the closing of the transactions contemplated by the Membership Interest Purchase Agreement and the ASL Asset Purchase Agreement. The CSI Asset Purchase Agreement defines aircraft delivery and acceptance conditions and sets forth various other covenants and obligations of the parties and prescribes potential remedies that are customary for an agreement of this nature.

ASL Asset Purchase Agreement

On December 15, 2025, the Company entered into an Asset Purchase Agreement with UMB Bank as Trustee for Associated Lease and Finance Group, LLC ("ASL") (the "ASL Asset Purchase Agreement") providing for the Company's sale of 12 Bombardier model CL-600-2B19 CRJ200 aircraft to ASL for a portion of the Aggregate Purchase Price.

The Company anticipates that the transactions contemplated by the ASL Asset Purchase Agreement will close promptly following the satisfaction of customary closing conditions and simultaneously with the closing of the transactions contemplated by the Membership Interest Purchase Agreement and the CSI Asset Purchase Agreement. The ASL Asset Purchase Agreement defines aircraft delivery and acceptance conditions and sets forth various other covenants and obligations of the parties and prescribes potential remedies that are customary for an agreement of this nature.

Aggregate Purchase Price

The Membership Interest Purchase Agreement, the CSI Asset Purchase Agreement, and the ASL Asset Purchase Agreement are interdependent and the closing of the transactions contemplated thereby are conditioned upon one another. The aggregate purchase price payable in connection with such transactions is expected to be approximately $113.2 million (the "Aggregate Purchase Price"), subject to adjustments pursuant to the terms of the applicable agreements. The allocation of such aggregate consideration among the individual transactions is set forth in, and governed by, the respective agreements.

Incorporation by Reference

The foregoing descriptions of the Membership Interest Purchase Agreement, the CSI Asset Purchase Agreement, and the ASL Asset Purchase Agreement do not purport to be complete and are qualified in their entirety by reference to the Membership Interest Purchase Agreement, the CSI Asset Purchase Agreement, and the ASL Asset Purchase Agreement, redacted copies of which will be filed as exhibits to the Company's Annual Report on Form 10-Kfor the fiscal year ended December 31, 2024, which will be filed with the Securities and Exchange Commission (the "SEC").

2025 Annual Meeting of Stockholders

The Company expects to hold its 2025 annual meeting of stockholders (the "Annual Meeting") on Tuesday, December 30, 2025 at 3:00 p.m. Eastern Time. The record date for the Annual Meeting is December 1, 2025. The Company's Notice of Virtual Annual Meeting of Stockholders (the "Notice") was first mailed to stockholders on or about December 5, 2025 (the "Mailing Date").

Stockholder Proposal and Director Nomination Deadlines

Because the scheduled date of the Annual Meeting represents a change of more than 30 days from the anniversary of the Company's 2024 annual meeting of stockholders, the advance deadlines set forth in the Company's Amended and Restated Bylaws (the "Bylaws") for stockholder proposals and director nominations are determined by reference to the date of the Annual Meeting, as described below.

Revised Deadline for Rule 14a-8Stockholder Proposals

The Company commenced mailing of the Notice as of December 5, 2025. As a result, stockholder proposals submitted pursuant to Rule 14a-8 ("Rule 14a-8")of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), after the Mailing Date are not eligible for inclusion in the Company's proxy solicitation materials for the Annual Meeting. Any stockholder seeking to present business at the Annual Meeting must comply with the advance notice provisions in the Bylaws described below.

Revised Deadline Under Advance Notice Bylaw Provision

The Bylaws include advance notice provisions applicable to stockholders seeking to bring director nominations or other business before an annual meeting other than pursuant to Rule 14a-8.These advance notice provisions require that, among other things, stockholders give timely written notice to the Company regarding such nominations or proposals and provide the information and satisfy the other requirements set forth in the Bylaws. Because the date of the Annual Meeting has changed by more than 30 days from the anniversary of the Company's 2024 annual meeting of stockholders, a stockholder's notice will be considered timely only if it is received by the Company (a) not earlier than the close of business on October 1, 2025, which is the 90th day prior to the date of the Annual Meeting; and (b) not later than the close of business on December 15, 2025, which is the later of (i) the 60th day prior to the date of the Annual Meeting, and (ii) the tenth day following the date on which the public announcement of the date of the Annual Meeting was first made. Stockholder notices must comply with all informational and procedural requirements set forth in the Bylaws.

Universal Proxy Rule Requirements

In addition to satisfying the foregoing requirements, to comply with the universal proxy rules, stockholders who intend to solicit proxies in support of director nominees other than the Company's nominees must comply with the requirements of Rule 14a-19under the Exchange Act no later than December 15, 2025, which is the later of 60 calendar days prior to the date of the Annual Meeting and the tenth calendar day following public announcement by the Company of the date of the Annual Meeting

Requirements Applicable to All Proposals and Nominations

All stockholder proposals or notices provided in compliance with the foregoing deadlines must be in writing and delivered to, or mailed to and received at, the Company's principal executive offices, addressed to the Company's Secretary at: Harbor Diversified, Inc., W6390 Challenger Drive, Suite 203, Appleton, Wisconsin, 54914.

The Company reserves the right to reject, rule out of order, or take other appropriate action with respect to any nomination or proposal that does not comply with the Bylaws, the Exchange Act, or applicable rules and regulations.