Archer Aviation Inc.

On or about March 2, 2026, we will issue warrants to a party to purchase an aggregate of 142,602 shares of our Class A common stock (the “Warrant”). The Warrant has an exercise price of $0.01 per share. The Form of Warrant is filed as Exhibit 10.21 to this Form 10-K.

The Warrant is being offered by us pursuant to our shelf registration statement on Form S-3ASR (File No. 333-284812), which was filed with the SEC on February 11, 2025 and was automatically effective on the same date, including the prospectus supplement dated October 21, 2025, and accompanying prospectus.

A copy of the opinion of Fenwick & West LLP relating to the validity of the Warrant is filed herewith as Exhibit 5.1.

Rule 10b5-1 Trading Plans. During the three months ended December 31, 2025, none of our directors or officers adopted, modified orterminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement”, in each case as defined in Item 408 of Regulation S-K, except as described below.

On December 1, 2025, Tosha Perkins, Chief Administrative Officer of the Company, adopted a trading arrangement, which expires December 31, 2026, and provides for the sale of up to 166,667 shares of Class A common stock pursuant to the terms of the plan.

On December 23, 2025, Eric Lentell, Chief Legal and Strategy Officer of the Company, amended a trading arrangement entered into on September 3, 2025, which expires on September 1, 2026, and provides for the potential sale of 100,000 shares of Class A common stock pursuant to the terms of the plan.

On December 30, 2025, Michael Spellacy, amember of the Board of Directors of the Company, adopted trading arrangement, which expires on December 31, 2026, and provides for the potential sale of 54,644 shares of Class A common stock held by Mr. Spellacy and 334,244 shares held by Achill Holdings, LLC, which is controlled by Mr. Spellacy, pursuant to the terms of the plan.