Zveno project
Zveno (Russian: Звено, lit. 'Flight') was a composite aircraft developed in the Soviet Union during the 1930s. It was the brainchild of the aviation engineer Vladimir Vakhmistrov. It consisted of a Tupolev TB-1 or a Tupolev TB-3 heavy bomber mothership and two to five parasite fighters. Depending on the variant, the fighters either launched with the mothership or docked in flight, and they could refuel from the bomber. The definitive Zveno-SPB using a TB-3 and two Polikarpov I-16s, each armed with two 250 kg (550 lb) bombs, was used operationally as a strategic weapon system with good results against targets in the Kingdom of Romania during the opening stages of the Eastern Front campaign in World War II. The same squadron later carried out an attack against a bridge on the Dnieper River that had been captured by German forces.