With its recoilless armament, the Soviet Union’s Grigorovich I-Zet was no ordinary fighter aircraft

During the 1920s, the Red Army command displayed a keen interest in special recoilless artillery systems — the so-called Dinamo-Reaktivnaya Pushka (DRP), Russian for ‘dynamic reaction cannon’. This was brought about by the demand to increase considerably the firepower of fighter aircraft, whose ordinary rifle-calibre machine guns were losing their efficiency against heavy, all-metal bombers. Leonid Kurchevsky was reckoned among the most successful inventors of recoilless guns in the USSR. He suggested a gun which, to reduce recoil, had a special Laval nozzle in its rear section.