Progress with the Olympus 593

WITH less than a year to go before the first flight of the Concorde it is heartening to learn that good progress is being made with the powerplant. In fact reports from Patchway are full of confidence that the joint development of the Olympus 593 turbojet engine by Bristol Siddeley Engines Ltd. and S.N.E.C.M.A. is proceeding well ahead of schedule. Already over 1,150 hours of development running has been accomplished on test beds in England and France, and at this comparatively early stage in the programme up to 100 hours per engine between strip and rebuild are being achieved, which exceeds the planned figure by a factor of two or three. The engine has already been run on the test bed, both with and without reheat, at thrusts in excess of the brochure performance of the Stage I engine. (The Concorde will first enter service in 1971 with Stage 0 engines of 32,825 lb. dry thrust plus 9 per cent reheat, which is a derated version of the full production Stage 1 engine designed for a dry thrust of 35,080 lb., and is to be introduced in 1973.) Ten of the programmed seventeen bench development engines have been built. Valuable results have already been obtained from the Vulcan flying test bed, which started its 250 hour programme of investigating the subsonic portion of the Concorde flight envelope last September.