07/07/2007. Remarks by Johan Visschedijk: "Original known as the Type 'Q', the first two of three prototypes were built to Spec. GR.17/45 as two-seaters, while the third and subsequent production aircraft were built as three-seaters.
The Gannet was powered by the 2,950 hp Armstrong Siddeley Double
Mamba (100) ASM.D I doubble airscrew-turbine engine unit. Each half
of the engine could be shut down and its propellor feathered, as can
be seen on the pictured second prototype. VR557 flew for the first
time on July 6, 1950."