BAE test pilot Graham Tomlinson, the lead STOVL pilot, engages the F-35B short takeoff/vertical landing, or STOVL, propulsion system in flight for the first time. Tomlinson climbs to 5,000 feet and engages the aircraft’s shaft-driven lift fan propulsion system at 210 knots, then slows to 180 knots with the system engaged before accelerating and converting back to conventional flight mode. The STOVL propulsion system is engaged for a total of fourteen minutes during the flight.