Lockheed XF-104 Starfighter
…the end of April, and work started on two prototypes late in May. The J79 engine was not yet ready, so both prototypes were instead designed to use the Wright J65, a licensed built version of the Armstrong Siddeley Sapphire. Construction of the first prototype XF-104 (US serial number 53-7786, Buzz number FG-786…