From 1960, the Yakovlev Design Bureau began work on a VTOL system, using the compact and lightweight Tumansky RU-19-300 turbojet engine, drafting a proposal for the Yak-104, a converted Yak-30 jet trainer with two vertically mounted Ru-19 engines between the inlet ducts of the standard Yak-30 powerplant. Work on the Yak-104 was terminated in favour of an aircraft with a single lift/cruise engine with rotating nozzles, similar to the Hawker Siddeley P.1127, which was nearing completion in England. Unable to find a suitable engine or convince the government to order the development of one, the Yakovlev bureau was forced to follow a different course.