Curtiss P-40 Warhawk

Country of Origin: us United States | Type: Single seat fighter-bomber

Introduction

The simple expedient of replacing the Curtiss Hawk 75/P-36's radial engine with a supercharged Allison V-1710 V12 created the Curtiss Model 81 P-40 series of fighters. The first XP-40 was a conversion of the 10th production P-36A, flying with its newly installed engine on 14th October 1938. Initially fitted with an underfuselage engine radiator which was subsequently moved to the more familiar lower nose position, the XP-40 impressed the USAAC sufficiently for it to place an order for 524 aircraft worth 12.9 million US dollars, at the time the largest contract issued to an American manufacturer since World War One.

Initial Variants

The initial production model was dubbed simply the P-40 and the first was flown in April 1940 with deliveries beginning two months later. There was no P-40A and the two major USAAC/USAAF production versions were the P-40B with additional wing guns and smoe armour protection, and the P-40C (flown in April 1941) with self sealing fuel tanks and provision for a drop tank. Of the 107 P-40B/Cs in Hawaii at the time of the Pearl Harbour raid, 80 were destroyed. The major user of the early model P-40 was the RAF under the name Tomahawk. Britain took over France's order for 230 aircraft on the latter's capitulation and also acquired large numbers in its own right. They were the Tomahawk I (equivalent to the basic P-40), IIA (P-40B) and IIB (P-40C) for a total of 1,180 aircraft incorporating British calibre (0.303 inch) wing guns.

Series Development

The development in 1940 of a new series of Allison V-1710 engines led to the Curtiss Model 87 Hawk series, beginning with the Model 87A P-40D and E, the first of which flew in May 1941. The engines featured some physical differences resulting in the new Hawks having a revised nose shape with raised propeller thrust line (which in turn allowed shorter main undercarriage legs), modified cockpit lines, a lowered and recontoured fuselage top line and the moving forward of the chin radiator. The new nose necessitated the moving of all gun armament to the wings and this was updated at the same time to 50-calibre weapons.

Major Production

The major production variant of the first series was the Model 87A-1 Kittyhawk IA for Britain and the Commonwealth nations, the first Hawk variant to be supplied under Lend-Lease. These found their way into RAF, RCAF and RAAF service from early 1942, the latter receiving the first of 163 in March 1942 (out of a total of 848 Kittyhawks) at a time when Australa was under threat of invasion by Japan and had no fighters. The Australian Kittyhawks were immediately pressed into action in the country's North and New Guinea.

Merlin Power

The decision to fit an American built Rolls Royce Merlin engine into the P-40 was taken due to the fact that although it was a rugged and tough workhorse, performance was not up to what was expected, and so the decision was to build them with these engines. Packard gained a licence to build the British Merlin 28 (designated V-1650-1 for the US) during late 1940, and it was fitted with a two speed turbocharger. Merlin powered P-40s were designated the P-40F (Hawk 87B by the factory), and the first of then (a P-40D) flew in June 1941. The British designation was Kittyhawk II. The P-40F was distinguishable from previous versions of the type by the removal of the carburretor intake fairing on the top of the engine cowling.

Later Models

Later models of the P-40 were powered by more powerful Allison engines, and were fitted with more armament. The P-40N was the most produced version of the later models, which accounted for almost 40% of the total production. Introduced in early 1943, the P-40N was an attempt to redress the aircraft's basic performance shortcomings which were becoming more marked as time went on. Weight saving was the key to its design with lightened structure, reduced armour, guns and ammunition removed and forward wing tanks eliminated.

Specification

Dimensions

Powerplant

Weights

Armament

Performance

Production

Production of the aircraft totalled 13,738, including:

Operators

Three-view Schematic

To view the schematic, click on the image below:

Specification view of a P-40