Grigorovich I-Z

The Grigorovich I-Z was a fighter aircraft developed in the Soviet Union during the 1930s. Advances in aircraft survivability thanks to all-metal construction and self-sealing and inert gas-filled fuel tanks led to experimentation with large-caliber weapons to shoot them down. In Soviet Union, Leonid Kurchevsky developed a series of recoilless rifles in various calibers and in 1930 was decided to adapt the 76.2 mm (3 in) weapons for aircraft use. The result was a conventional strut-braced monoplane with fixed landing gear. A pair of Kurchevsky APK (APK - Aviatsionnaya Pushka Kurchevsky - aircraft cannon Kurchevsky) rifles were mounted under the wings outside the propeller arc and the rear fuselage and tail assembly were of reinforced metal construction to withstand the blast. A single small-caliber synchronized machine gun in the left fuselage was added to aid the pilot in aiming. Two prototypes were built, the first flying in mid-1931. The second strengthened I-Zbis flew at the begi