This is the STOVL propulsion system for the first Lockheed Martin F-35B, seen on Pratt & Whitney's test rig before being delivered to Lockheed Martin's F-35 final assembly line in Fort Worth, Texas in late November. The STOVL propulsion system for all initial F-35Bs will consist of Pratt & Whitney F135 engines and Rolls-Royce lift fan systems, along with Rolls-Royce-provided three-bearing swivel ducts and roll post ducts. Pratt & Whitney developed the aircraft's stealthy exhaust nozzle and all the propulsion-system software. Credit: Pratt & Whitney
