The Douglas O-43 was a monoplane observation aircraft used by the United States Army Air Corps.
Development
Five Y1O-31A service-test aircraft were ordered in 1931, and delivered to the USAAC in early 1933 designated Y1O-43. They differed from the final configuration of the O-31A, with a wire-braced parasol wing, and a new fin and rudder. An order for 23 O-43A aircraft was completed during 1934, with a deepened fuselage, which eliminated the need for the ventral bulge under the observer's position. Powered by a single 675 hp Curtiss V-1570-59 inline engine, it also had taller vertical surfaces with an inset rudder similar to the O-31A. The canopy was enlarged, and fully enclosed both cockpits. The O-43 and O-43A served with the USSAC observation squadrons for several years before being assigned to National Guard units, such as the 111th Observation Squadron Brownwood Airfield Texas, 15th Observation Squadron Fort Sill Oklahoma, and 3rd Observation Squadron Langley Field Virginia.
Below Y1O-43







Below O-43A









Below the 24th airframe of the O-43A contract was completed as the XO-46 prototype.


Specifications (O-43A)
General characteristics
Crew: 2
Length: 33 ft 11 in (10.34 m)
Wingspan: 45 ft 11 in (14.00 m)
Height: 12 ft 3 in (3.73 m)
Wing area: 334 sq ft (31.0 m2)
Empty weight: 4,135 lb (1,876 kg)
Gross weight: 5,300 lb (2,404 kg)
Powerplant: × Curtiss V-1570-59 Conqueror V-12 liquid-cooled piston engine, 675 hp (503 kW)
Propellers: 3-bladed metal propeller
Performance
Maximum speed: 190 mph (310 km/h, 170 kn)
Cruise speed: 163 mph (262 km/h, 142 kn)
Service ceiling: 22,400 ft (6,800 m)
Time to altitude: 5,000 ft (1,500 m) in 3 minutes 18 seconds
Wing loading: 15.8 lb/sq ft (77 kg/m2)
Power/mass: 0.127 hp/lb (0.209 kW/kg)
Armament
Guns: 1x fixed and 1x flexible .30 cal (7.62 mm) Browning machine gun
(Text from Wikki)