The Curtiss Falcon is a family of military biplane aircraft built by the United States aircraft manufacturer Curtiss Aeroplane and Motor Company during the 1920s. Most saw service as part of the United States Army Air Corps as observation aircraft with the designations O-1 and O-11, or as the attack aircraft designated the A-3 Falcon. U.S. Navy variants were used initially as fighter-bombers with the designation F8C Falcon, then as the first U.S. Marine Corps dive bombers with the name Helldiver. Two later generations of Curtiss dive-bombers would also be named Helldiver.