Its power output (thrust) was not high enough for use as a practical engine in a production aircraft[1] and was used only for research into VTOL.

(The next lift engine, the RB.162, would have a compressor built mainly from glass-fibre composite and have a higher T/W ratio.)

When a fifth engine was installed in the SC.1 to provide forward thrust it had to be mounted at about 45 degrees to remain within the envelope.

The Vereinigte Flugtechnische Werke (VFW) SG 1262 used five RB.108s, three mounted in tandem on the centreline, with one RB.108 either side.

A similar lift jet was designed by Bristol Siddeley, the BS.59, with a thrust of 8,000 lb the engine was intended for the projected Focke-Wulf Fw 260.