Tupolev ANT-29

The Tupolev ANT-29, with the military designation DIP (Dvukhmotorny istrebitel pushechny, meaning twin-engined cannon fighter), was a twin-engined, cannon-armed fighter of the 1930s, designed by Alexander Arkhangelsky and built by Tupolev. Design work began in 1932 on an aircraft able to carry two APK-100 cannon. The result was a monoplane with a tall, narrow fuselage, powered by two Hispano-Suiza 12Ybrs engines. The cannon were mounted at the bottom of the fuselage and, unusually, could be reached by the crew in flight for loading and maintenance. It first flew in February 1935, had a crew of three and a top speed of 352 km/h. During tests the machine had reasonable performance but was longitudinally unstable, and the aircraft did not enter production.