Approx 5,000 P-39s in total were supplied to the USSR from 1941 to late 1944. At first these were aircraft bought by Britain and unwanted by the RAF. They were followed by aircraft on the British Lend Lease account and then supplied by Britain on to the USSR as Lend lease by Britain to the USSR (Many of these never physically touched U.K. soil). After that deliveries were direct to the USSR on their own Lend lease account. Over half of all P-39s to the USSR were flown on the ALSIB route from the “lower” US via Canada and Alaska to Siberia from 1942 until late 1944. Approx 2,400 P-63 Kingcobras were delivered by the same route from late 1943 (note the overlap with the P-39). They were not issued to operational units until May 1945 so saw no action against the Luftwaffe. They were however in time to see combat during Operation August Storm against the Japanese and scored at least one air to air victory in what was a rather one sided campaign.