sorties, 20 Luftwaffe fighters and three Junkers Ju 87s were shot down while Soviet losses amounted to two Yak-3s shot down. A large dogfight developed on 16 June 1944, when 18 Yak-3s clashed with 24 German aircraft. Soviet Yak-3 fighters shot down 15 German aircraft for the loss of one Yak destroyed and one damaged. The following day, Luftwaffe activity over that section of the front had virtually ceased. On 17 July 1944, eight Yaks attacked a formation of 60 German aircraft, including escorting fighters. In the ensuing dogfight, the Luftwaffe lost three Ju 87s and four Bf 109Gs, for no loss. The Luftwaffe issued an order to "avoid combat below five thousand metres with Yakovlev fighters lacking an oil cooler intake beneath the nose!" Luftwaffe fighters in combat with the Yak-3 tried to use surprise tactics, attacking from above. Unresolved wartime problems with the Yak-3 included plywood surfaces delaminating when the aircraft pulled out of a high-speed dive, short-range and poor engine reliability. The pneumatic system for actuating landing gear, flaps and brakes, typical for all Yakovlev fighters of the time, was troublesome. Though less reliable than hydraulic or electrical alternatives, the pneumatic system was preferred owing to the weight saving. In 1944, the Normandie-Niemen Group re-equipped with the Yak-3, scoring the last 99 of their 273 air victories against the Luftwaffe. Total Yak-3 losses in combat were 210, 60 in 1944 and 150 in 1945. Variants Yak-3 main production version Yak-3 (VK-107A) Klimov VK-107A engine with and 2 × Berezin B-20 cannons with 120 rpg. After several mixed-construction prototypes, 48 all-metal production aircraft were built in 1945–1946 during and after WW2. Despite excellent performance ( at ), it saw only limited squadron service with the 897th IAP. Though the problems with the VK-107 overheating were eventually mitigated, it was decided to leave the engine for the better-suited Yak-9. Yak-3 (VK-108) Yak-3 (VK-107A) modified with VK-108 engine with , and armed a single Nudelman-Suranov NS-23 cannon with 60 rounds of ammunition. The aircraft reached at in testing but suffered from significant engine overheating. Another Yak-3 with 2 × Berezin B-20 cannons was also fitted with the engine with similar results. Yak-3K Armed with a Nudelman-Suranov NS-45 cannon, only a few built because Yak-9K was a better match for the weapon Yak-3P Production started after war armed with 3 × Berezin B-20 cannon with 120 rounds for the middle cannon