The United States bought its first 10 torpedo bombers in 1921, variants of the Martin MB-1. The squadron of U.S. Navy and Marine fliers was based at Naval Weapons Station Yorktown. General Billy Mitchell suggested arming the torpedo bombers with live warheads as part of (the anti-ship bombing demonstration) but the Navy was only curious about aerial bomb damage effects. Instead, a trial using dummy heads on the torpedoes was carried out against a foursome of battleships steaming at 17 knots. The torpedo bombers scored well.