BB-MAI
 BB-MAI (Russian: ББ-МАИ) was a Soviet light bomber/attack plane prototype aircraft. Designed in 1939 by Pyotr Grushin of the Moscow Aviation Institute (MAI hence the designation) it was delayed by problems with the new Klimov M-105 engine and eventually only a single prototype was built. While the design was not accepted for serial production it was the first Soviet aircraft to use a tricycle landing gear and one of the first to feature a supercharger and leading-edge slats.