In some ways the Gloster Javelin was a less-than-ideal engine test platform, but two examples performed exactly that role
ENGINE TEST JAVELINS
With its twin engines situated in wing-mounted nacelles, the Gloster Meteor proved ideal for testing alternative power units, such was the relative ease with which the nacelles could be adapted.The manufacturer’s follow-on Javelin all-weather fighter had its twin powerplants housed within the fuselage and so, in theory, was less suited to operations as a testbed, at least outside the area of fitting new versions of its standard Sapphire engines. But two Javelin FAW1s were adapted to take entirely different units.
THE GYRON JUNIOR JAVELIN
The Javelin FAW1 to 6 were all powered by two Armstrong Siddeley Sapphire Sa 6s.The FAW7 had a more powerful version of the Sapphire, and the FAW8 introduced afterburning.
It is understood that there was never a strong possibility of production machines receiving a different make of powerplant, but an early production FAW1, XA552, was used as a trials platform for the de Havilland Gyron Junior, selected to power the Bristol 188 supersonic research aircraft and the Blackburn Buccaneer naval strike aircraft. Much of the detail text…