The beginning of the 1945.
Yak-3 (VK-107A) modified with VK-108 engine with 1851 hp, and armed a single 23 mm Nudelman-Suranov NS-23 cannon with 60 rounds of ammunition. The aircraft reached 745 km/h at 6290 m in testing but suffered from significant engine overheating.
Another Yak-3 with 2 × 20 mm Berezin B-20 cannons was also fitted with the engine with similar results.