Two primary components provide the vertical lift necessary for hover, namely Rolls-Royce’s shaft-driven LiftFan and 3-Bearing Swivel Module (3BSM).
According to Lockheed Martin, the LiftFan is mounted horizontally behind the cockpit. As the aircraft transitions to hover mode, two doors open on top of the aircraft and the two counter-rotating fans blow approximately 20,000 pounds of unheated air straight down, producing almost half of the downward thrust needed for a pure hover mode.
The majority of the remaining vertical thrust is provided by the 3BSM at the rear of the aircraft. With the ability to quickly swivel ninety-five degrees downward, the 3BSM can direct up to 18,000 pounds of heated thrust from the engine exhaust.
Click here to read The Engineer’s report on how Britain’s vertical lift expertise is keeping the F-35B combat aircraft aloft.