Archer Aviation Inc.

Item 3.02 Unregistered Sales of Equity Securities. The disclosure set forth in Item 8.01 below with respect to the issuance of the Resale Shares (defined below) is incorporated by reference into this Item 3.02.

Item 8.01 Other Events. Vendor Share Issuances On August 18, 2026, Archer Aviation Inc. (the “Company”) filed a prospectus supplement pursuant to Rule 424(b) under the Securities Act of 1933, as amended (the “Securities Act”), with the Securities and Exchange Commission (the “SEC”), relating to shares of Class A common stock, $0.0001 par value per share (“Class A common stock”) that the Company issues to certain vendors from time to time in exchange for services rendered and/or goods purchased (the “Vendor Share Issuances”), as previously disclosed in its quarterly and annual reports. This prospectus supplement covers the resale of 8,261,273 shares (the “Resale Shares”) of Class A common stock, of the Company that were issued by the Company to the applicable vendors. The prospectus supplement forms a part of the Company’s Registration Statement on Form S-3 (No. 333-284812), which was originally filed with the SEC on February 11, 2025 (the “Registration Statement”). The Resale Shares were issued pursuant to stock purchase agreements, on or about August 17, 2026, by and among the Company and applicable vendors in connection with the Vendor Share Issuances. The Resale Shares were issued in reliance on Section 4(a)(2) of the Securities Act. The Company did not receive any cash proceeds from this issuance. A copy of the legal opinion of Fenwick & West LLP relating to the validity of the Resale Shares is filed as Exhibit 5.1 to this Current Report on Form 8-K and is filed with reference to, and is hereby incorporated by reference into, the Registration Statement.