The Lockheed Martin F-35B Lightning II short takeoff/vertical landing (STOVL) stealth fighter engaged its STOVL propulsion system in flight for the first time on January 7th. The successful test is the first in a series of planned STOVL-mode flights that will include short takeoffs, hovers and vertical landings.
The aircraft is powered by a single Pratt & Whitney F135 engine driving a Rolls-Royce LiftFan. The system, which includes a Rolls-Royce 3-bearing swivel duct that vectors engine thrust and under-wing roll ducts that provide lateral stability, produces more than 41,000 pounds of vertical thrust.