Lift Engines

Another method for achieving vertical flight uses separate engines for lift and for forward flight. The lift engines are used to get airborne, and then separate forward thrust engines propel the plane normally. Once the plane is flying forward and the wings are generating lift, the lift engines are shut down. The disadvantage of this design is that the aircraft has to carry the dead weight of the lift engines, which reduces its performance.

One example of this type of aircraft is the Russian Yakovlev Yak-38 Forger. It has three jet engines. Two lift engines behind the pilot blow air straight down. The main engine provides thrust from two nozzles behind the wing. These nozzles can rotate to direct the jet exhaust downward to provide extra lift. The Yak-38 serves on Russia’s Kiev class aircraft carriers.