single-wheel main landing gear with two-wheeled units and the fuselage upper decking was cut down. Around the same time Factory No. 1 ceased production and Factory No. 81 in Moscow continued to work on the aircraft. Aircraft built by Factory No. 81 were of better quality because the surface finish was better and the engine cowlings and doors were more closely fitted to minimize drag. These improvements increased the speed by . Development work continued and resulted in the Yak-4 when Klimov M-105 engines were fitted. A grand total of 201 Yak-2s were built before production was terminated in April 1941. Aviation historian Bill Gunston reports that several prototype variants were built, including the R-12 reconnaissance aircraft which retained the original positioning of the crew, put three cameras in the fuselage and added a bomb bay for eight FAB-20 bombs behind the pilot. Another was the I-29 or BB-22IS escort fighter with restored fuel and two 20 ShVAK cannon underneath the fuselage. But neither of these can be confirmed by other, post-Cold-War sources. Russian aviation historian Yefim Gordon does mention a Yak-2KABB ground-attack variant which might have been confused with the I-29 because it had two ShKAS in the nose and two ShVAK cannon in a depressible ventral pack. Unfortunately no other details are available, although photos do exist. Another variant mentioned by Gordon was the BPB-22 (Blizhiy Pikeeruyushchiy Bombardirovshchik — short-range dive bomber) prototype that was fitted with two M-105 engines, dive brakes and an automatic dive entry/exit control system. It was first flown at the end of October 1940 although it crashed during the test programme when fuel unexpectedly cut out, but not before it was flown to a maximum speed of . Operational history When the Germans invaded the Soviet Union on 22 Jun 1941, 73 Yak-2s were in service, mostly with the 316th Reconnaissance Regiment in the Kiev Military District. Most of these were destroyed in the opening days of the campaign; the 316th mustered only four on 11 July. Variants Ya-22 Prototype. BB-22 Initial production with flush rear canopy Yak-2 (VVS designation used in service of izdeliye 70 / BB-22 2M-103) Two-seat light bomber/reconnaissance aircraft. BPB-22 (aka BPB-22 2M-105, BB-22PB) Blizhiy Pikeeruyushchiy Bombardirovshchik — short-range dive bomber. Prototype only. Yak-2KABB Prototype ground-attack aircraft fitted with the KABB-MV gun/bombing installation (KABB-MV - kombineerovannaya artillereeysko-bombardirovochnaya batareya Mozharovskovo i Venevidova - combined gun/bomb battery designed by Mozharovskiy and