Curtiss XP-22 Hawk
# Curtiss XP-22 Hawk

The Curtiss XP-22 Hawk was a 1930s American experimental biplane fighter built by Curtiss for evaluation by the United States Army Air Service.

## Design and development

In 1929, the AAC ordered three P-11 Hawks for testing of the 600 hp (447 kW) H-1640 Chieftain engine. This engine proved a failure, and before completion, one of the three was converted to use a 9-cylinder 575 hp (429 kW) Cyclone, being completed as the YP-20. Testing with the R-1820 was prolonged, so the Army acquired another of the three P-11s, instead. This became the XP-22.

A number of changes were made for installing the 700 hp (520 kW) Curtiss V-1570 Conqueror engine. The radiator was relocated, a new cowl was fitted, and the tail was given more fin and less rudder area, and featured a steerable tailwheel, rather than the original skid. For these changes, Curtiss charged only US$1.

During testing, the XP-22 underwent a number of alterations and improvements, including a change from a three-strut landing gear to a single streamlined strut, later fitted with wheel pants. Fillets were added where struts joined the wing and the tail was briefly reduced in area, to P-6 standard. The XP-22 was also the Army's first fighter capable of 200 mph (320 km/h), achieving 202 mph (325 km/h).

## Operational history

In June 1931, the AAC held a competition to evaluate the P-6, P-12, YP-20, and XP-22. The XP-22 came out the winner, earning a contract for 45 aircraft as the Y1P-22. Following the trials, the XP-22 donated a nose and landing gear graft to the YP-20, which became the XP-6E, and the 45 production aircraft were completed to this standard.

## Operators

### United States

* United States Army Air Forces

## Specifications (XP-22 Hawk)

Data from U.S.Fighters, Curtiss Aircraft 1907–1947

General characteristics

* Crew: 1
* Length: 23 ft 7 in (7.19 m)
* Wingspan: 31 ft 6 in (9.60 m)
* Height: 8 ft 10 in (2.69 m)
* Airfoil: Clark Y
* Empty weight: 2,597 lb (1,178 kg)
* Max takeoff weight: 3,354 lb (1,521 kg)
* Powerplant: 1 × Curtiss V-1570-23 Conqueror V-12 water-cooled piston engine, 575 hp (429 kW)
* Propellers: 2-bladed propeller

Performance

* Maximum speed: 202 mph (325 km/h, 176 kn)
* Service ceiling: 26,500 ft (8,100 m)

Armament

* Guns: 2x 0.300 in (7.62 mm) machine-guns in the fuselage sides
