Armstrong Siddeley Motors: Minutes of a meeting to review the Python position

Development position: 670 hours running have been carried out during the period, making a total of 12153 hours P.240: Has now completed a 150-hour test using oil spec. DerD.2472 A/O. The engine has been rebuilt to the same standard and is now on hangar test at Rotol P.146: Has completed a 150-hour test using oil to specification DerD.2487 (RDE/0/463). Like P.240 the engine incorporated satellite roller bearings with steel cages, the strip condition of the bearings being generally OK P.103: Further testing of a standard BTH starter fitted with bronze seal ring was unsuccessful P.105: As a result of cracking in the serrations of a twin disc turbine following a hangar endurance test, further tests have been carried out to improve the disc cooling P.104: A turbine failures was experienced on this engine while running on the hangar test bed at Rotol. On strip, the failure was found to be due to a cracked 1st turbine nozzle inner blade ring Engine troubles: 1 Disc cracking 2 Combustion chambers 3 Reverse torque switch 4 Failure of compressor blades: 26 May 1953 P.146 Bench 2nd row 798.5 hours 23 November 1953 P.168 Flight 2nd row 95.0 hours 24 November 1953 P.181 Flight 2nd row 94.5 hours 19 November 1953 P.146 Bench 8th row(2blades) 500 hours 18 September 1950 P.103 Bench 2nd row 176 hours All these failures are attributed to vibrational fatigue 5 Igniters 6 Inertia controller units 7 Bursting of cartridge safety discs 9 Other matters arising on Python engines (a) Satellite roller bearings (b) Increased capacity scavenge pump (c) Stall recovery experiments. Have been carried out on P.240 (d) Jet pipe temperature control (e)Alternative fuels (f) Fuel pump seizure (g) Build standard of production engines on conversion to twin discs (h) Flow control unit (j) Tight fit turbine blades (k) Failure of some PCU pumps to deliver on starting up (l) Electrical harness (m) Cracked inner blade ring 2 Flight report: 4 hours flying has been carried out on our Wyvern VZ.747 Deck landing trials on HMS Illustrious 3 RTO memo: X.25/2687/JAF. There were a number of defects arising out of the trials last October on HMS Eagle