Memo from Mr Palmer to Mr Golovine Armstrong Siddeley Motors: Javelin trials by US...

I consider that the remarks made by the US pilots in respect of engine control basically true; we have been in this trouble on all Sapphires for a very long time. The main point of development to improve engine operation are: 1 A negative creep governor is being tested on the Sapphire Canberra at Bitteswell. This has showed improvement but requires further development. 2 Pressure tapping changes re. being made to the governor; it is hoped to allow full engine speed at altitude without exceeding jet pipe limitations. A variable nozzle is under development for the same reason. 3 In an effort to improve handling at the top end of the power range flow control, units with springs of different ratings are under test. The summary points out that climbs on fixed throttle settings are difficult to achieve