The Thomas-Morse O-19 was an American observation biplane built by the Thomas-Morse Aircraft Company for the United States Army Air Corps.
The O-19 was based on the earlier Thomas-Morse O-6 biplane. It was a conventional two-seat biplane of metal construction with fabric-covered wings and tail surfaces. The design was evaluated with a number of different engine installations and the type was ordered into production as the O-19B with a Pratt & Whitney R-1340-7 Wasp radial engine.
XO-19Improved version of the XO-6 with a 450 hp (340 kW) Pratt & Whitney R-1340-3 engine, one built.
YO-20Similar to the XO-19 with a 525 hp (391 kW) Pratt & Whitney R-1690-1 engine, one built.
XO-21Similar to the XO-19 with a 600 hp (450 kW) Curtiss H-1640-1 engine, one built, later re-engined as the XO-21A.
XO-21AThe XO-21 fitted with a 525 hp (391 kW) Wright R-1750-1 engine.
O-19Service evaluation aircraft with a 500 hp (370 kW) Pratt & Whitney R-1340-9, two built.
O-19AO-19 without the 88 US Gallon main fuel tank, one built.
O-19BProduction version with a 450 hp (340 kW) Pratt & Whitney R-1340-7 engine, two
machine-guns and modified cockpit, 70 built.
O-19CO-19B with tailwheel, ring cowl and minor changes, 71 built.
O-19DOne O-19C converted as a VIP staff transport with dual controls.
O-19EO-19C with extended upper-span wing and a 575 hp (429 kW) Pratt & Whitney R-1340-15 engine, 30 built.
O-21O-19 with 600 hp (450 kW) Curtiss H-1640 Chieftain engine, one built, one converted.
YO-23XO-19 with a 600 hp (450 kW) Curtiss V-1570-1 Conqueror engine, one built.
Y1O-33One O-19B re-engined with a 600 hp (450 kW) Curtiss V-1570-11 engine and revised tail surfaces, one converted.
Y1O-41A sesqui-plane conversion of the Y1O-33 with a 600 hp (450 kW) Curtiss V-1570-79 engine, one converted. Later modified by
Consolidated Aircraft as their
Model 23 and exported to Mexico.
Y1O-42High-wing monoplane version of the Y1O-41, static test airframe only.
United StatesUnited States Army Air CorpsData from The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985), 1985, Orbis Publishing, Page 3000
General characteristics
Crew: twoLength: 28 ft 4 in (8.64 m)Wingspan: 39 ft 9 in (12.12 m)Height: 10 ft 6 in (3.20 m)Wing area: 348 ft2 (32.33 m2)Empty weight: 2722 lb (1235 kg)Gross weight: 3800 lb (1724 kg)Powerplant: 1 × Pratt & Whitney R-1340-7 Wasp radial piston engine, 450 hp (336 kW)Performance
Maximum speed: 137 mph (220 km/h)Service ceiling: 20,500 ft (6250 m)Armament
2 x 0.3in (7.62mm) machine-guns (one fixed forward-firing, one movable in rear cockpit)