Lift Engine, Aircraft

a gas-turbine engine, usually of somewhat simplified design, that develops vertical thrust for vertical takeoff and landing (VTOL) aircraft. Lift engines are installed on an aircraft in combination with engines that produce horizontal thrust. They must have a reliable starting system. For safety, several lift engines are installed in an aircraft. Those that create horizontal as well as vertical thrust during takeoff and landing are called lift-acceleration engines. Aircraft lift engines have a short service life between repairs. They may be installed in combination with booster units for takeoff and landing.