Armstrong Siddeley Viper position meetings: Notes on a meeting held to review the...

Present state of development: Total running time to date 509 hours. Engine V.4 has carried out a 10-hour modification approval test to clear the production control SCH.2482/5 and the shut-off cock SCH.2752. Engine V.1 attempted a 100-hour scaled down type test. A failure of the 1st row compressor rotor occurred after 35 hours at 8050 rpm. Three engines have been delivered to Australia: 3rd prototype V.10; 4th prototype V.8; First production engine V.1001. Outstanding troubles: Compressor thrust bearings (expendable engine), Hoffmann bearing 4989 in the condition as type tested is considered satisfactory for Australian production. Long-life engine: The whole of the front bearing and accessory system is being redesigned for this engine and the Ransome and Marles bearing will be used for this and provision is also being made for a larger bearing if it proves necessary. Long-life engine: The general bearing arrangement remains the same as for the expendable engine but a Sapphire type oil will be used. Compressor failure: 12 blades were either broken or cracked on V.1 after a complete failure at 8050 rpm. Long-life engine: The chamber will have to be redesigned with Sapphire inner and outer flame tubes and high energy ignition. High altitude rig tests at the RAE. Turbine (long-life engine): Requires some improvement on the nozzle guide vane assembly to reduce distortion of the blade holding rings