Sky Harbour Group Corp-A美股市值招股说明书(2026-01-02版)

Up to $100,000,000 Class A Common Stock This supplement no. 1 (this “Supplement”) amends and supplements certain information contained in our sales agreementprospectus filed as part of our registration statement on Form S-3 and having an effective date of April 10, 2024 (File No. 333-278275) (the “sales agreement prospectus,” as amended and supplemented by this Supplement (the “ATM Prospectus”)) relating tothe issuance and sale of shares of our Class A common stock, par value $0.001 per share (“Class A Common Stock”), having anaggregate gross sales price of up to $100,000,000, offered by the ATM Prospectus pursuant to an “at-the-market” equity offeringprogram. This Supplement should be read in conjunction with the sales agreement prospectus and is qualified by reference thereto, This Supplement is being filed to reflect the Amended and Restated At Market Issuance Sales Agreement, datedDecember 31, 2025 (the “A&R Sales Agreement”), by and among us, B. Riley Securities, Inc. (“B. Riley Securities”) and YorkvilleSecurities, LLC (“Yorkville Securities”), pursuant to which, among other things, Yorkville Securities was added as an additionalsales agent. Accordingly, each reference to the term “B. Riley Securities” in the sales agreement prospectus shall include Yorkville As of the date of this Supplement, we have offered and sold 110,148 shares of Class A Common Stock under the SalesAgreement having an aggregate gross sales price of approximately $1.4 million, and shares of Class A Common Stock having an Our Class A Common Stock is listed on the New York Stock Exchange (“NYSE”) under the symbol “SKYH.” OnDecember 30, 2025, the last reported sale price of our Class A Common Stock on the NYSE was $8.81 per share. Investing in our Class A Common Stock involves risks. Before buying our securities you should carefully read theentire ATM Prospectus, including this Supplement, and the documents incorporated by reference therein and herein,including the section of the sales agreement prospectus entitled“Risk Factors”beginning on page S-4, the section of this Supplement entitled“Risk Factors”beginning on page 1 and the risks set forth under the caption“Item 1A. Risk Factors”of our most recently filed Annual Report on Form 10-K, as well as additional risks that may be described in future reportsor information that we file with the Securities and Exchange Commission (the“SEC”), including our Quarterly Reports on Neither the Securities and Exchange Commission nor any state securities commission has approved or disapprovedof these securities or determined if the ATM Prospectus, including this Supplement, is truthful or complete. Anyrepresentation to the contrary is a criminal offense. Yorkville Securities B. Riley Securities The date of this Supplement is December 31, 2025. Table of Contents The following sections of the sales agreement prospectus are hereby amended and supplemented as follows: RISK FACTORS Investing in shares of our Class A Common Stock involves a high degree of risk. Before purchasing shares of our Class ACommon Stock, you should carefully consider the following risk factors as well as those discussed under the section entitled“RiskFactors”in our Annual Report on Form 10-K for the year ended December 31, 2024, and any subsequent Quarterly Report onForm 10-Q or Annual Report on Form 10-K, together with the other information contained in this Supplement, the documentsincorporated by reference and in any free writing prospectus we have authorized for use in connection with this offering. Each ofthese risk factors, either alone or taken together, could adversely affect our business, operating results and financial condition, aswell as adversely affect the value of an investment in shares of our Class A Common Stock. There may be additional risks that we Risks Related to This Offering Our management team will have broad discretion over the use of the net proceeds we receive in this offering, and we may usethese proceeds in ways with which you may not agree. We currently intend to use any net proceeds we receive in this offering for working capital, site acquisition and marketingexpenses to fund the growth of our business, capital expenditures, repayment of debt (including the Yorkville Promissory Note (asdefined below), and general corporate purposes; however, we have considerable discretion in the application of the proceeds. Tothe extent that we use a portion of the net proceeds from this offering to repay borrowings under the Yorkville Promissory Note,this affiliate will receive any amount of the Yorkville Promissory Note that is repaid with the net proceeds from this offering. Youwill not have the opportunity, as part of your investment decision, to assess whether the net proceeds we may receive in thisoffering are being used by us in a manner agreeable to you. You must rely on management’s judgment regarding the application of If you purchase shares of our Class A Common Stock in this off