The introduction with the P-40D (Hawk 87A-1) of the Allison V-1710-39 engine into the P-40 family significantly altered the appearance of the nose section. The radiator was enlarged and moved forward, the two guns on the upperside of the engine cowling were omitted in favor of four wing-mounted 12.7mm guns and provision was made for a 227kg bomb or a drop tank under the fuselage. In British service this and the following P-40 models were designated as "Kittyhawks". After the production of only a few P-40Ds the armament was augmented to six wing-mounted 12.7mm guns in the P-40E (Kittyhawk Mk.I). The P-40E variants were the first P-40s to be built in really large numbers (2,320 aircraft - 280 of them remaining in the USA, the others being exported). The Kittyhawk Mk.IA or P-40E-1 was similar, but purchased with Lend-Lease funds for Britain. These aircraft became operational with the RAF in North Africa at the beginning of 1942. Traced from available illustrations it is very likely that a number of P-40Es were also among the Kittyhawk variants delivered to the Soviet Union from 1942 on, albeit only very little and unprecise information about this version can be found in the available sources.
In an attempt to improve the P-40's performance at altitude, a version with the Packard-built Rolls-Royce Merlin engine was produced under the designation P-40F in 1942. The British designated this version as Kittyhawk Mk.II and from this model on the USAAF adopted the name "Warhawk" for its P-40s. The installation of the Merlin engine with its different carburetor system again changed the nose contours - now the intake above the cowling was gone. To improve directional stability, beginning with the second production batch the overall length had been increased a little bit. Of the 1,311 P-40Fs built 250 were purchased with Lend-Lease funds and earmarked for the RAF (but in fact never received by this service). 100 examples (out of the batch FL219-FL448) of this type are known to have been delivered to the Soviet Union. A lightweight version of this type was the P-40L with reduced armor and armament (only four guns).
The next variant P-40K (Kittyhawk Mk.III) reverted again to the Allison engine - in a more powerful version. The first two batches had the short fuselage of the P-40E, but the extra power caused a tendency to swing during take-off. To correct this fault, a dorsal fin was added in front of the rudder. Later production batches omitted this fin in favour of the longer fuselage of the P-40F. As with the previous versions, a large proportion of the 1,300 P-40Ks built was delivered to numerous Allied nations and again the Soviet Union received its share, too. But as with the P-40E, reliable figures are lacking in the available documentations.
The P-40M appeared in November 1942 and was built in 600 examples solely for Lend-Lease supply to Britain as Kittyhawk Mk.III. Evidence can be found for at least 170 machines of this type (ex-RAF FS100-FS269) to be delivered to the USSR.
The last major production version of the P-40 and the one built in the largest number was the P-40N, which appeared in March 1944. This type had a new lightweight structure and in the first production batch (with a top speed of 608km/h at 3,200m the fastest of all P-40s) carried only four wing guns. From the second batch on the six-gun armament was re-instated, together with a redesigned canopy. In British service this type was designated Kittyhawk Mk.IV. A large proportion of the P-40s delivered to Russia were P-40Ns, but exact figures are lacking.
In Soviet service the Kittyhawk was used by the VVS, the PVO and the Naval Air Arm. Generally the type was not very well liked by the Russians, who complained that it could not absorb as much battle damage as the P-39 Airacobra. And there were the serious problems with the engines - the most prominent victim of an engine failure by a P-40 was perhaps Boris Safonov, the leading ace of the VVS-SF.
|None. End of development.|
|Function||Fighter and fighter-bomber|
|Type||1*Allison V-1710-39||1*Packard (Rolls-Royce) Merlin V-1650-1||1*Allison V-1710-73||1*Allison V-1710-81||1*Allison V-1710-81, -99 or -115|
|Power at take-off||1,150hp at 3,000rpm||1,300hp at 3,000rpm||1,325hp||1,200hp at 2,800rpm|
|Power at altitude||1,150hp at 3,570m||1,120hp at 5,640m||1,150hp at 3,600m||1,125hp at 5,275m|
|Length||9.50m||10.16m (early models 9.50m)||10.16m|
|Weights and loads|
|Wing Load (kg/m2)||190||193||207||184||236|
|Power load (kg/hp)||3.63||3.79||3.94||3.59||4.60|
|Climb rate at 1,525m||640m/min||?m/min||658m/min||625m/min||646m/min|
|Climb rate at 3,050m||?m/min||680m/min|
|Climb rate at 4,570m||442m/min||?m/min||503m/min||?m/min|
|Guns||6*mg 12.7mm Colt-Browning M-2 (281 rounds/gun)||4 or 6*mg 12.7mm Colt-Browning M-2 (281 rounds/gun)|
|Bombs||1*227kg and 2*45kg||3*227kg|
|Fuel (internal capacity)||594l||462l|
|Fuel (drop tanks)||1*197, 284 or 643l|