 The full-scale mock-up was approved on 28 March 1930 and the first prototype, designated VT-11 ("Vnutrenniya Tyurma"—Internal Prison), was completed a month later.It made its first flight on 30 April 1930 and was fitted with an imported supercharged Jupiter VII.It was painted in silver with a red cheat line; a red "VT" was superimposed on the red star on the rudder.