Curtiss YP-37
# Curtiss YP-37

The Curtiss P-37 was an American fighter aircraft made by Curtiss-Wright in 1937 for the US Army Air Corps. A development of the Curtiss P-36 Hawk to use an inline engine instead of the radial engine of the P-36 the fuselage was lengthened and the cockpit moved back. A small number of YP-37 aircraft was built for Air Corps evaluation. The expected top speed was not achieved and the project terminated in favor of the Curtiss P-40.

## Design and development

In early 1937, after realizing the P-36 Hawk was inferior to more modern European designs, the USAAC ordered Curtiss to adapt one P-36 to the new liquid-cooled turbo-supercharged Allison V-1710. The prototype Hawk was fitted with a turbo-supercharged 1,150 hp (860 kW) Allison V-1710-11 as the XP-37 (company designation Model 75I). The cockpit was moved back towards the tail to make room for the massive turbo-superchargers, and the engine was cooled by two radiators on either side of the nose. Armament was one 0.30 in (7.62 mm) M1919 Browning machine gun and one 0.50 in (12.70 mm) M2 Browning heavy machine gun mounted in the nose.

Although the turbo-supercharger was extremely unreliable and visibility from the cockpit on takeoff and landing was virtually nonexistent, the USAAC was sufficiently intrigued by the promised performance to order 13 service test YP-37s and spares at a contract cost of $531,305.12 in 1938. These aircraft were powered by an improved V-1710-21 with a more reliable supercharger mounted in a lengthened nose. However, reliability problems and poor visibility continued to plague the YP-37, and the project was canceled in favor of a parallel development, the P-40 Warhawk.

## Variants

### XP-37

    One aircraft built with a V-1710-11 engine.

### YP-37

    13 aircraft built with a V-1710-21 engines and extended fuselage

## Specifications (YP-37)

Data from Curtiss aircraft 1907-1947, Baugher : Curtiss XP-37

General characteristics

* Crew: 1
* Length: 32 ft 11.5 in (10.046 m)
* Wingspan: 37 ft 3.5 in (11.367 m)
* Height: 11 ft 1 in (3.38 m)
* Wing area: 236 sq ft (21.9 $m^2)$
* Airfoil: root: NACA 2215; tip: NACA 2209
* Empty weight: 5,592 lb (2,536 kg)
* Gross weight: 6,700 lb (3,039 kg)
* Powerplant: 1 × Allison V-1710-21 V-12 liquid-ciooled piston engine, 1,000 hp (750 kW)
* Propellers: 3-bladed Curtiss electric constant-speed propeller

Performance

* Maximum speed: 340 mph (550 km/h, 300 kn) at 10,000 ft (3,000 m)

             331 mph (288 kn; 533 km/h) at 20,000 ft (6,100 m)
* Cruise speed: 305 mph (491 km/h, 265 kn)
* Range: 570 mi (920 km, 500 nmi)
* Service ceiling: 34,000 ft (10,000 m)
* Rate of climb: 2,920 ft/min (14.8 m/s)
* Time to altitude: 20,000 ft (6,100 m) in 8 minutes 30 sec

Armament

* Guns: 1 x 0.30 in (7.62 mm) M1919 Browning machine gun and 1 x 0.50 in (12.7 mm) M2 Browning machine gun
