1947, the Metrovik F.9 Sapphire was handed to Armstrong
Siddeley. Armstrong Siddeley improved the engine's thrust from
7,500 lb to 11,000 without afterburning (augmentation) over its
To gain entry into the turbojet market, Wright
purchased a license to build the Sapphire (re-designated the J65).
The engine was Americanized and redesigned...a process which took
two years longer than expected. By then the market had been
taken over by the Pratt & Whitney J57.