Douglas_XA-2 Knowpia

XA-2
	Douglas XA-2 with removed cowling on the lower nose to enhance engine cooling
Role	Attack aircraft
National origin	United States
Manufacturer	Douglas Aircraft Company
Status	Prototype
Primary user	United States Army Air Corps
Number built	1
Developed from	Douglas O-2

The Douglas XA-2 was an American prototype attack aircraft converted from a Douglas O-2 observation aircraft in the spring of 1926 by Douglas Aircraft. Only one prototype aircraft was built and the type was not ordered into production.

Design and development edit

One Douglas O-2, serial number 25-380, was modified for the new role as an attack aircraft. While the basic structure of the aircraft remained, there were several modifications made. The water-cooled Liberty engine (V-1650) of the O-2 was replaced by an inverted air-cooled Allison VG-1410 engine. The lower engine cowlings were omitted to allow for more cooling air flow over the engine.

Second, the XA-2 was more heavily armed than the O-2. It had six forward-firing .30-caliber Browning machine guns - two in the nose forward of the cockpit, and two each in the mid-upper and lower wings. Two .30-caliber Lewis guns were put on a flexible mount for use by the observer-gunner in rear defense of the aircraft.^[1] The aircraft also had the capacity for a small bomb load of 100 lb (45 kg).

The Douglas XA-2 was evaluated against the Curtiss XA-3 (a conversion of the Curtiss O-1B observation plane). The Douglas Aircraft won the initial competition, but the Army realized that the Liberty engine was both underpowered and in dwindling supply. It ordered a second competition with both models upgraded with Packard 1A-1500 engines. The Curtiss aircraft won this time and became the U.S. Army Air Corps' frontline attack aircraft (Curtiss A-3 Attack Falcon) from 1928 to 1935.

Operators edit

United States

United States Army Air Corps

Specifications (XA-2) edit

General characteristics

Crew: Two (pilot & observer / gunner)
Length: 29 ft 7 in (9.02 m)
Wingspan: 39 ft 8 in (12.09 m)
Height: 11 ft (3.4 m)
Max takeoff weight: 4,985 lb (2,261 kg)
Powerplant: 1 × Allison VG-1410 inverted air-cooled V-12 piston engine, 433 hp (323 kW)

Performance

Maximum speed: 130 mph (210 km/h, 110 kn)
Cruise speed: 100 mph (160 km/h, 87 kn)
Range: 400 mi (640 km, 350 nmi)
Service ceiling: 15,000 ft (4,600 m)

Armament

Guns:
- 6 × forward firing .30-cal. (7.62 mm) Browning machine guns, two in the fuselage + one in each wing
- 2 × flexible .30-cal. Lewis machine guns
Bombs: Provision for 100 lb (45 kg) of bombs mounted on lower wing racks