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

Development position: 171 hours running have been carried out during the period, making a total of 11,302 hours P.240: Has now completed its 150-hour mod Approval test and is now on inspection. Troubles encountered during test: 1 Satellite roller bearing. Failed after 13 hours. The inner race having broken down and cages disintegrated 2 The starter drive shaft on the engine was found to be damaged after 110 hours, 130 hours, and on completion of test 3 Fuel pipe failures. After 87 hours No.1 main burner fuel feed pipe fractured and was replaced. In the next 20 hours this pipe failed again twice and No.4 pipe failed once 4 Igniters. After the failures of igniters D.9202/6 after 70 hours of schedule standard J pipe igniters failed. D.9202/6 igniters were assembled at Armstrong Siddeley Motors incorrectly and not heated and tightened to required torque 5 Jet pipe temperature control. After 80 hours the selector was found faulty, the wiper track being badly pitted 6 Turbo starter. Some difficulty was experienced in starting at temperatures around zero, it being necessary at times to warm the cartridges to room temperature 7 Performance: Initial performance curve 3490SHP 4040 TESP Final performance curve 3335SHP 3860 TESP 8 Strip comments 9 (a) Turbine first nozzle blade ring cracked and manifold distorted (b) Satellite roller bearing inner track again breaking down. Rollers not correctly blended (c) Earthed reverse torque switch. The earthed contact spring was burnt out due to test bed wiring faults (d) Combustion chambers. Flame tubes were in very good condition. Mixing chamber back plate was distorted to some extent and one cracked P.103: As an alternative to Lucas acceleration control the following schemes are being tried: (a) The Armstrong Siddeley Motors scheme for delaying the movement of the flow control unit. Not yet available (b) Automatic stall recovery connected with jet pipe temperature control is being tested P.104: Further tests required to assess stator cooling and tip clearance effects P.105: At Rotol on ICU development, but at the moment P.146 is taking its place on the test bed p.146: At Rotol for 25-hour special category test to clear the engine, together with PCU and propeller 2 Other matters arising on Python engines: 1 Jet pipe temperature control. Except for a faulty selector on P.240, reported above, the control worked satisfactorily and the faulty wiper is considered a casualty as it is suspected that heavy current passed through it on rig test 2 Anti-icing 3 Low oil pressure 4 Alternative fuels 5 Fuel pump seizures 6 Reverse torque switch 7 Tropical trials at Khartoum. P.146 is at Rotol to undergo 25 hours special category test to clear 80C and 90C oil inlet temperature. This engine is also fitted with an ECU 8 Engine troubles: 9 (a) Turbine feed manifold (b) New tabwashers for layshaft bearing nuts (c) Loose igniters (d) Turbine blade fit (e) Front and seizure P.192 (f) Fuel pipe failures on P.239 (g) Flight idling stop setting (h) BTH starters P.174 Returned from flight at RAE. for investigation of reported metal in filters P.175 Returned from Rotol for investigation into fire at the rear of the engine P.115 Is on investigation 9 RTO memos: X.25/482/JAF Failure of a valve on a starter trolley. Mr Slatter reported that design action was in hand 10 Python Mk.3 technical certificate. Deals with Mr Eals' objection of 25 February