P-40 Tomahawk/Kittyhawk/Warhawk
Curtiss P-40 Warhawk
Description
Role	Fighter-Bomber
Crew	1
Manufacturer	Curtiss
Weights
Empty	6,300 lb	2,858 kg
Loaded	8,400 lb	3,810 kg
Maximum Takeoff	9,100 lb	4,128 kg

The Curtiss P-40 was an American fighter aircraft which first flew in 1938 and played a vital role in the crucial middle stages of World War II. Developed from the pre-war radial-engined P-36 Hawk, the P-40 became known as the Tomahawk, the Kittyhawk, and finally the Warhawk in different theatres.

The first XP-40 was simply a P-36A Hawk with its Pratt & Whitney Twin Wasp radial engine replaced by a supercharged Allison V-1710 engine. The liquid-cooled Allison offered no more power than the radial, but its smaller frontal area led to considerably lower drag. In April 1939 the USAAC, no doubt looking over its shoulder at the sleek new high-speed in-line engined fighters of Europe, placed the largest single fighter order it had ever made for fighters: 524 aircraft.

France ordered 140 as the Hawk 81A-1 but collapsed before they had left the factory, and the aircraft were diverted to British Commonwealth service, as the Tomahawk 1 - in some cases complete with metric instruments. Deemed unsuitable for use as a fighter in Europe, where it was thought inferior to the Spitfire, Hurricane and Bf-109, the Tomahawk was used for training and some low-level tactical reconnaissance. It proved much more valuable in the deserts of North Africa, where poor high-altitude performance mattered less and the Tomahawk's rugged airframe, relatively heavy armament, and good range was valuable. RAF No. 112 Sqn was the first to fly Tomahawks in the Western Desert, mainly for ground attack, and copied the famous sharkmouth markings under the spinner from Luftwaffe destroyer units, later adopted by the Flying Tigers in China.

Departing from normal USAAC convention, there was no P-40A. Some records indicate this might have been reserved for a reconaissance variant that was briefly in devlopment by Curtiss, but quickly discarded.

Revised versions of the P-40 soon followed: the P-40B or Tomahawk IIA had extra 0.30 in (7.62 mm) US, or 0.303 in (7.7 mm) UK machine guns in the wings and self-sealing tanks; the P-40C or Tomahawk IIB added underbelly drop tank and bomb shackles, as well as improved self-sealing fuel tanks and other minor revisions, but the extra weight did nothing to help the aircraft's lack-lustre performance. (Weight was always a major problem for the P-40.)

Only a small handful of P-40Ds were made--less than 50. With a new, larger Allison engine, slightly narrower fuselage, redesigned canopy, and improved cockpit, the P-40D eliminated the nose-mounted .50 in guns and instead had a pair of 0.5 in (12.7 mm) guns in each wing. The distinctive chin airscoop grew larger in order to adequately cool and aspirate the large Allison engine.

The P-40E or Kittyhawk I was very similar in most respects to the P-40D, except for a slightly more powerful engine and an extra .50 in gun in each wing, bringing the total to 6. Some aircraft also had small underwing bomb shackles.

Further variants included:

P-40F and L, which both featured a Packard Merlin engine in place of the normal Allison, and thus did not have the carborateur scoop on top of the nose. The L in some cases also featured a fillet in front of the vertical stabilizer, or a stretched fuselage to compensate for the higher torque

P-40K, an Allison engined P-40L, with the nosetop scoop retained and the Allison configured scoop and cowl flaps

P-40M, a P-40E with a more powerful Allison engine and minor other improvements

P-40N, the final production model. The P-40N featured a stretched rear fuselage to counter the torque of the larger, late-war Allison engine, and the rear deck of the cockpit behind the pilot was cut down at a moderate slant to improve rearward visibility. A great deal of work was also done to try and eliminate excess weight to improve the Warhawk's mediocre speed. Early N production blocks dropped a .50 in (12.7 mm) gun from each wing, bringing the total back to 4; later production blocks reintroduced it after complaints from units in the field.

P-40Q with a 4 bladed prop, cut down rear fuselage and bubble canopy, supercharger, squared off wingtips and tail surfaces, and improved engine was tested, but its performance was not enough of an improvement to merit production when compared to the current late model P-47Ds and P-51Ds pouring off the production lines. With the end of hostilities in Europe, and the introduction of the P-47N and P-51H (the latter which did not see combat), the P-40 came to the end of its life.

Despite its lifelong reputation as a mediocre aircraft, it was sturdy, fast in a dive, posessed a respectable rate of roll, was easy to maintain, and was well armed. Of all the aircraft built by the US during WWII, it was the third most-produced: the British Commonwealth alone took 930 aircraft, issuing them to 16 squadrons (including two South African Air Force units) and sending 23 on to serve with the Soviet air force. The Royal Australian Air Force equipped its 3 Squadron, 75 Squadron, 76 Squadron, and 120 Squadron (Netherlands East Indies) with P-40s, 75 and 76 Squadron being instrumental in the defeat of the Japanese at the Battle of Milne Bay.

14,000 P-40s were produced up to 1944 and they were used by the airforces of twenty-eight nations. It saw the majority of its frontline action in both the China-Burma-India Theater and the Mediterranian Theater with the USAAC and Commonwealth forces, and with the VVS (USSR air force) on the Eastern Front. The VVS also converted some of their Warhawks to domestic Klimov engines for ease of maintinence and repair.

P-40E
Span: 37 ft 4 in (11 m)
Length: 31 ft 9 in (10 m)
Height: 12 ft 4 in (3.75 m)
Weight: 9,100 lb (4 t) loaded
Armament: 6 x 0.5 in (12.7 mm) machine guns; 700 lb (300 kg) of bombs externally.
Engine: Allison V-1710 1150 hp (860 kW)
Maximum speed: 362 mph (580 km/h)
Range: 850 miles (1350 km)
Service ceiling: 30,000 ft (9100 m)

P-40N
Span: 37 ft 4 in
Length: 33 ft 4 in
Height: 12 ft 4 in (3.75 m)
Weight: 8,850 lb loaded
Armament: 6 x 0.5 in (12.7 mm) machine guns; 500 lb (230 kg) of bombs.
EngineOne Allison V-1710-81 at 1,200 hp
Maximum speed: 350 mph at 16,400 ft
Range: 750 miles
Service ceiling: 31,000 ft
P-40N information from http://www.hill.af.mil/museum/photos/wwii/p-40.htm