However, on the Gyron Junior, positioning of the vanes was not reliable and could cause surging which, in turn, could prevent accelerating to higher thrust levels.

The engine had to supply air for the aircraft's boundary layer control system and the resulting thrust loss was unacceptable.

The 188 was originally intended to have the Rolls-Royce Avon but the half ton lighter Gyron Junior was substituted in June 1957.

Limitations included poor fuel consumption of the Gyron Junior and engine surging.

Also on display at the Gatwick Aviation Museum, Charlwood, Surrey, two running engines can also be found here, fitted to Buccaneer S.1, XN923.