Material Agreement, Reorganization, Management Change/Compensation (Form 8-K)

On August 29, 2025, Harbor Diversified, Inc. (the "Company"), which is the indirect parent of Air Wisconsin Airlines LLC ("Air Wisconsin"), entered into a non-bindingletter of intent (the "LOI") with Premier Shuttle Holdings, LLC, an affiliate of the Slate Aviation companies (the "Buyer"). The LOI contemplates a proposed transaction (the "Proposed Transaction") pursuant to which the Company would sell all of the equity of AWAC Aviation, Inc. ("AWAC"), which is a direct wholly owned subsidiary of the Company and the direct parent of Air Wisconsin, to the Buyer. The Proposed Transaction would have the effect of transferring to the Buyer certain operating assets including, among other things, Air Wisconsin's Part 121 air carrier certificate issued by the Federal Aviation Administration, a number of complete aircraft and additional airframes, Air Wisconsin's rotable parts inventory, and certain spare parts and related equipment.

The Proposed Transaction contemplates a purchase price consisting of an initial cash payment and Buyer notes, including a note to finance the acquisition of a portion of the aircraft and airframes, and a note to finance the acquisition of the rotable parts inventory. The definitive terms of the consideration to be paid, including the aggregate value of the consideration and the terms of the notes, are subject to additional negotiation.

The LOI is non-bindingand subject to the negotiation and execution of definitive agreements, completion of due diligence, and satisfaction of customary closing conditions. There can be no assurance the Proposed Transaction will be consummated on the terms described herein or at all.

The Company is evaluating the Proposed Transaction as part of its ongoing assessment of strategic alternatives for Air Wisconsin and its related operations. The Company expects those assets not included in the Proposed Transaction will be distributed to the Company, or to another subsidiary of the Company, which will continue to pursue opportunities in the sales and leasing of aircraft, engines, and parts.

On August 29, 2025, Air Wisconsin informed all of its 253 employees that it is implementing a workforce reduction plan. These notices, which may be required by law in advance of potential furloughs in certain locations, were issued pursuant to the Worker Adjustment and Retraining Notification Act. As of the date hereof, the Company expects that workforce reduction actions may take effect on or after October 28, 2025, although it has not made a final determination as to the termination of any particular employee or group of employees at this time. Air Wisconsin is taking these actions to re-balanceits workforce in light of evolving business needs and to provide the Buyer with flexibility to determine future staffing requirements in connection with the Proposed Transaction. Further, the Company may retain a number of Air Wisconsin employees to support the Company's ongoing efforts to sell or lease aircraft, engines, and parts not transferred in connection with the Proposed Transaction, or to pursue other strategic opportunities.

At this time, the Company is unable to make a good faith determination of an estimate or range of estimates as required by paragraphs (b), (c), and (d) of Item 2.05 of Form 8-Kwith respect to such workforce reduction actions. The Company will file an amendment to this Current Report on Form 8-K(this "Current Report") after it makes a determination of such estimate or range of estimates.

Liam Mackay resigned from his position as Air Wisconsin's Chief Financial Officer, effective September 5, 2025.

On September 1, 2025, Air Wisconsin's board of managers appointed Gregg Garvey, Air Wisconsin's current Senior Vice President, Chief Accounting Officer, and Treasurer, to serve as Air Wisconsin's Senior Vice President, Chief Financial Officer, and Treasurer, effective immediately. Mr. Garvey will succeed Mr. Mackay as the Company's principal financial officer effective as of September 1, 2025, and will continue serving as the Company's principal accounting officer.

As a result of the appointment, Mr. Garvey's base salary increased to $255,000. No other changes were made to his compensation arrangement.

Mr. Garvey, age 60, has served as Air Wisconsin's Senior Vice President, Chief Accounting Officer and Treasurer since October 2018, and has worked with Air Wisconsin in various roles since 1999. Mr. Garvey also serves as Vice President, Chief Financial Officer and Treasurer of AWAC. Prior to joining Air Wisconsin in 1999, Mr. Garvey served as a Tax Manager, Tax Supervisor, and Staff Accountant at Schenck & Associates (currently part of CliftonLarsonAllen LLP), a large regional public accounting firm in Appleton, Wisconsin. Mr. Garvey also held the positions of Financial Analyst and Forecasting Accountant and Senior Tax Accountant at Repap Wisconsin, Inc., a paper company formerly located in Kimberly, Wisconsin. Mr. Garvey holds a B.B.A. in Accounting from the University of Wisconsin-Whitewater, an M.S. in Taxation from the University of Wisconsin-Milwaukee, and an M.B.A. from the University of Wisconsin-Oshkosh. Mr. Garvey is also a Certified Public Accountant.

There are no arrangements or understandings between Mr. Garvey and any other person pursuant to which he was selected to serve as Chief Financial Officer. There are no family relationships between Mr. Garvey and any director, executive officer, or person nominated or chosen by the Company to become a director or executive officer. Except for his employment relationship with the Company and the compensation arrangements arising in connection therewith, there are no relationships involving Mr. Garvey that are required to be reported pursuant to Item 404(a) of Regulation S-K.