Hamilton Model Aero Club

This months Feature:

Curtiss P-40

Variants/Other Names: Warhawk; Tomahawk; Kittyhawk)

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The P-40 fighter/bomber was the last of the famous "Hawk" line produced by Curtiss Aircraft in the 1930s and 1940sThe P-40 was the best known Curtiss-Wright airplane of World War II. It was also one of the most controversial fighters of the war. It was vilified by many at the time as being too slow, lacking in maneuverability, having too low a climbing rate, and being largely obsolete by contemporary world standards even before it was placed in production . The inadequacies of the P-40 were even the subject of a Congressional investigation. It gets regularly included on lists of the worst combat aircraft of World War 2.
All of these criticisms certainly had some degree of validity, but it is also true that the P-40 served its country well during the war in the Pacific. YES, the P-40 was developed from an older design. YES, it had altitude limitations, but it was a tough plane that had a good roll rate, good armament, dive speed, and could take punishment. Along with the P-39 Airacobra, the P-40 was the only American fighter available in quantity to confront the Japanese advance during the first year of the Pacific War. It helped stem the speed of the Japanese advance until more modern types could be made available in quantity. The P-40 had no serious vices and was a pleasant aircraft to fly, and, when flown by an experienced pilot who was fully aware of its strengths and weaknesses, was able to give a good account of itself in aerial combat. Strangely enough, the P-40 continued in production long after later and more modern types were readily available, the numbers manufactured reaching the third highest total of American World War II fighters, after the Republic P-47 and the North American P-51. At the peak of wartime production, the entire Curtiss Airplane Division complex of factories was producing sixty aircraft A DAY! A total of 13,739 Curtiss P-40s were built, which included the Tomahawks and Kittyhawks built for export as well as the P-40s built for the USAAF. The P-40 was already obsolete by European standards even before the first prototype flew, and it never did catch up. The P-40 had been developed basically as a low-altitude close-support fighter under mid-1930s US tactical concepts

The origin of the P-40 can be traced back to 1935 and the Curtiss P-36 (Model 75) fighter, which was powered by a radial, air-cooled engine. Realizing that the radial-engined P-36A was at the limit of its development, Curtiss designer Donovan Berlin got USAAC permission in July 1937 to install a 1150 hp Allison V-1710-19 liquid-cooled engine with integral supercharging in the 10th P-36A . This project was given the company designation of Model 75P

P-36
The next step toward what was eventually to emerge as the P-40 was the 1937, XP-37, in which the P-36 design was reworked to incorporate a turbosupercharged Allison V-1710 liquid cooled V-type engine. XP-37

XP-37
Problems with the turbosupercharger caused the development of the XP-37 to be abandoned in favour of a less complex and more more direct conversion of the P-36 for the Allison V-1710 engine, the XP-40 . XP-40

First XP-40
There had to be a considerable amount of replumbing to adapt the P-36 airframe to the liquid-cooled Allison. The carburetor intake for the single-stage supercharger was installed in the upper nose, between the two nose guns. An oil cooler was mounted underneath the nose, and the radiator was located in a ventral position just aft of the wing. Unlike in the XP-37, the cockpit remained in the same location as in the P-36. The XP-40 flew for the first time on October 14, 1938, with test pilot Edward Elliot at the controls. Armament was two 0.50-inch machine guns located in the upper fuselage deck and synchronized to fire through the propeller arc, standard armament for US pursuit aircraft at the time. Wing racks could be fitted for six 20-pound bombs. Early flight trials were disappointing, the aircraft’s top speed being barely 300 mph. Initially, the coolant radiator was placed under the fuselage aft of the wing, it was moved forward until it finally ended up located underneath the extreme nose. The radiator intake was redesigned to include an oil cooler as well as two coolers for the ethylene/glycol engine coolant. XP-40

Final XP-40
The maximum speed of the XP-40 was 342 mph at 12,200 feet at a gross weight of 6260 pounds. This was faster than the Hawker Hurricane, but slower than the Spitfire or the Bf 109E. Range was 460 miles at 299 mph with 100 gallons of fuel. With 159 gallons of fuel at 200 mph, a range of 1180 miles was claimed, almost twice that of the contemporary Hurricane, Spitfire, and Bf 109E. Wingspan was 37 feet 4 inches, wing area was 236 square feet, length was 31 feet 1 inch, and height was 12 feet 4 inches. The wingspan and wing area were to remain the same throughout the entire history of the P-40 production run
P-40D

P-40D

Prior to the final termination of P-40 development, some effort was expended in combining aerodynamic refinement with increased power to produce a higher-performance model.The definitive XP-40Q (converted from a P-40N-25 airframe) had clipped wing tips, the cut-down aft fuselage with bubble canopy and coolant radiators faired into the wing leading edges. Four 12.7mm guns were carried but proposed production models were to have carried, either six 12.7mm or four 20mm weapons. No production was undertaken. P-40Q

P-40Q

Between 1942 and 1946, the Royal New Zealand Air Force (RNZAF) operated 297 P-40's (although four were destroyed before being officially brought on strength) of various models (E, K, L, M, N). The aircraft were assigned to Nos 14, 15, 16, 17, 18, 19 and 20 Fighter Squadrons, and No's 2 and 4 (F) OTU. Nos 14 thru 19 Squadrons flew P40's in the Pacific, carrying out offensive and defensive fighter operations, bomber escort, and dive-bombing duties. A total of 99 Japanese aircraft were destroyed in the air, with 14 probables recorded. 20 P-40's were lost in combat, and a further 152 in accidents in New Zealand and overseas. The P-40 began to be replaced in front line duties by F4U-1A's from 1944. The remainder were sold for scrap in 1948.

Torokina
Torokina strip Bougainville

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P-40M

XP-37

Hamilton Model Aero Club Inc. 2008