Tomahawk/Kittyhawk Models
Tomahawk (Model 81) A total of 1180 delivered under British direct-purchase contracts. In addition, the RAF took over ten P40C fighters from the USAAC. The RAF operated them as Tomahawks of an unspecified mark and without RAF serial numbers.
Tomahawk I (Model H81-A) A total of 140 equivalents to the USAAC P40, except for four wing guns, were ordered on two contracts with deliveries commencing in April 1940. It was decided that these were unsuitable for combat use and they were relegated to training roles.
Tomahawk II Designation not used officially for specific aircraft, but was a generalisation for improved Tomahawks delivered during October and November 1940.
Tomahawk IIA (Model H81-A2) Protective armour and externally-covered self-sealing fuel tanks on 110 aircraft equivalent to the P40B. 23 transferred to the USSR and one to Canada as an instructional airframe.
Tomahawk IIB (Model H-81-A2, A3) A total of 930 in four lots. These were generally equivalent to the P40C and were used extensively by the RAF and SAAF in North Africa as from 16 June 1941. Of these, 100 fighters unofficially designated H81-A3 were released to China and used by the AVG. A further 23 went to the USSR, and unspecified numbers went to Turkey and Egypt.
Kittyhawk The French contract for Curtiss Model 87s was taken over by Britain prior to construction commencing. The airframe and engine changes justified the new name - Kittyhawk. A total of 560 was procured on direct-purchase contracts and a further 2432 were supplied by the Lend-Lease programme, bringing the total to 2992.
Kittyhawk I (Model A87-A2) Fitted with four .50 cal wing guns, the 560 fighters were comparable to the P40D. The UK took over the initial French order and deliveries commenced in August 1941, with 72 diverted to Canada, and 17 to Turkey.
Kittyhawk IA (Model H87-A3, A4) The 1500 fighters were direct equivalents of the P40E and were delivered under the USAAC designation P40-1 to distinguish the British equipment etc. from those for US service. Many were diverted to Canada, Australia and New Zealand.
Kittyhawk II (Model H87-B3) WW2 British sources identify the 330 RAF P40Fs and P40Ls as Kittyhawk IIs; later records list the first 230 as Kittyhawk IIAs. 81 were transferred to the USAAC overseas and 7 were given to the Free French Air Force. RNZAF had one.
Kittyhawk III Of the 616 Kittyhawk IIIs, the first 192 were P40K-1s, the next 160 were P40Ls, and the final 264 were P40Ms. The last 170 were diverted to the USSR. 9 P40K-1s were delivered to the RCAF on 26 Nov 1942 retaining their US serials.
Kittyhawk IV (Model H87V, W) The final 586 Kittyhawks were USAAC P40Ns delivered from Mar 1943 - Jan 1944 of which 130 were diverted to the USSR. The type was used by the RAAF, RNZAF and the RCAF.
(When Curtiss introduced the P40F powered by the Rolls Royce Merlin engine, the new name Warhawk was applied to distinguish it from the Allison-engined P40D and P40E. This name was not adopted by the RAF for the re-engined model, and the name Kittyhawk was retained for both versions of the Model 87).
Taken from 'Lend-Lease Aircraft in World War II' - Arthur Pearcy
