Aeroplane & Armament experimental establishment, Boscombe Down to MoS: Python engine...

As a result of the meeting of 30 November 1951, at Armstrong Siddeley Motors at which A & AEE representatives were present, the following points were raised: 1 Compressor stalling by throttle opening. It is obvious that the Python engine is sensitive to throttle opening from ground idling to flight idling position. A compressor stall can be induced by a relatively small throttle movement. 2 Jet-pipe temperature limitations. The A & AEE representative raised the question of the limit of 580C at ground idling laid down by the operational limitations on the Python Volume 1. Experience at Boscombe Down has shown that a JPT of 400C, is never exceeded during normal ground running or taxiing. As the JPT gauge installed in the Wyvern held by this establishment is only graduated from 400C upwards, the exact temperature at these conditions cannot be quoted