page_title: Curtiss Falcon
section_title: U.S. Army Air Corps
hierarchical_section_title: Curtiss Falcon / Variants / U.S. Army Air Corps
context_page_description: The Curtiss Falcon was a family of military biplane aircraft built by the American 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.
  The type was introduced in 1925 and saw first-line service in the United States until 1934. Curtiss Falcons fought in the Constitutionalist Revolution of 1932 in Brazil, used by the forces of São Paulo.
context_section_description: A-3
  Model 44, attack aircraft version of O-1B, armed with two 0.30 in (7.62 mm) machine guns and 200 lb (91 kg) of bombs; 66 built for the USAAC.
  A-3A
  Six A-3s converted into trainers.
  A-3B
  Model 37H, attack version of O-1E, with six machine guns, including two mounted in wings; 78 built.
  XA-4
  One A-3 with a Pratt & Whitney R-1340-1 Wasp radial piston engine. Scrapped in March 1932, but the design was the basis for the naval variants.
  A-5
  Proposed A-3 variant with Curtiss V-1570 Conqueror engine
  A-6
  Proposed A-3 variant with Curtiss H-1640 Chieftain engine
  XBT-4
  Model 46, one O-1E converted into a basic trainer for the USAAC.
  XO-1
  Liberty 12A powered Prototype, later modified to use a Packard 1A-1500, one built.
  O-1
  Model 37A, two-seat observation aircraft, the first production model, ten built. One converted into the O-1 Special VIP transport.
  O-1A
  Two-seat observation aircraft, powered by the Liberty piston engine, one built.
  O-1B
  Model 37B, first major production version, powered by Curtiss D-12D (V-1150-3) engine; 45 ordered, 25 built and 20 diverted on the production line to the A-3.
  O-1C
  Four O-1Bs converted into VIP transports.
  O-1E
  Model 37I, variant powered by 435 hp (324 kW) Curtiss D-12E (V-1150-5) piston engine; 41 built.
  O-1F
  Model 37J, one O-1E converted into VIP transport.
  O-1G
  Model 38, final O-1 variant, powered by a 712 hp (531 kW) Wright R-1820F-2 Cyclone engine; 30 built for USAAC.
  XO-11
  Two O-1 modified as O-11 prototypes.
  O-11
  O-1 airframe powered by the Liberty V-1650 piston engine; 67 built concurrently with the O-1s.
  XO-12
  One XO-11 prototype redesignated XO-12.
  XO-13
  O-1 fitted with 720 hp (540 kW) Conqueror engine for the 1927 National Air Races.
  XO-13A
  Second XO-13, fitted with wing skin radiators.
  O-13B
  One O-1C fitted with a Conqueror engine, tested as an observation aircraft, and provided to Secretary of War.
  YO-13C
  Three O-1Es re-engined with 600 hp (450 kW) direct-drive Conqueror engines.
  YO-13D
  One O-11 fitted with supercharged Conqueror engine.
  XO-16
  One O-11 with Prestone cooling system.
  XO-18
  One O-1B testbed for Curtiss H-1640 Chieftain engine.
  Y1O-26
  One O-1E fitted with a geared Conqueror engine.
  O-39
  O-1G refitted with a Conqueror engine and cockpit canopy; ten built.
caption: Curtiss XA-4 Falcon
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