FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1961
1961 - 0979.PDF
FLIGHT, 20 July 1961 79 Bristol Siddeley Orpheus 803 turbojet AERO ENGINES 1961 . . and if the development engines due to run during the coming winter confirm these figures the commercial success of the BS.75 should be assured. It is sized to fill a gap which has not yet been attended to by any other manufacturer, and although its most obvious immediate application, the British Aircraft Corporation 107, is temporarily shelved, the powerplant "has been chosen for at least two other projects, not including the Avro 771." BS projects Although it is never likely to be built, the BS.58 has been included in the table of turbofans largely in order to give a clue to the characteristics of the BS.53 Pegasus, from which it is derived. The BS.72 commercial fan engine has figured in some published papers, but is again not a likely runner, and the most important gleam in the eye of the BS board is a unit said to be designated BS. 100. According to unofficial reports, this is a lift/thrust engine rated at something like 30,0001b at sea level, a figure which would enable aircraft designers to produce a really worthwhile V/STOL attack machine. Although obviously based on both Pegasus and Olympus, such an engine would probably require a wholly new front fan; and, in supersonic applica- tions, fan burning. Olympus First run in 1950 at its design rating of 9,1401b—then an ambitious figure—this superb two-shaft turbojet has been developed until it now has a dry thrust in excess of 20,0001b and a reheat rating of 33,OOOlb. The original version of the engine entered production in 1955 with a dry rating of 11,0001b, and this series terminated with the Olym- pus 104, the standard powerplant of the Vulcan B.I, with a dry rating of 13,5001b. Bomber Command have announced that these engines are "the RAF's most powerful, most efficient, and most reliable combat engine, with the highest overhaul life and lowest premature-removal rate." Engine handling has also been officially praised, "particularly at heights above 50,000ft." Second-generation engines began with the BO1.6 Mk 200, in which airflow was increased and the number of compressor stages reduced without any penalty in overall pressure ratio. The standard powerplant of the Vulcan B.2 is the BO1.7 Mk 201, and the behaviour of the Vulcan 2 in operational service suggests that this much more powerful engine is in no way inferior to its predecessor. The BO1.21 clearly has a zero- stage, and has been designed "to allow the Vulcan to reach its ultimate design potentialities." In production form the 21 is the Olympus Mk 301, and it is at present flying in the engine manufacturer's own Vulcan test bed. A development of such an engine, fitted with Bristol Siddeley/ Solar fully variable reheat, has a thrust of 33,OOOlb. Engines of this type are making good progress ID the challenging search for the optimum powerplant installation for the British Aircraft Corporation TSR.2. It is appropriate to note that this experience should carry across directly to a supersonic transport. Orpheus Simplicity and reliability were uppermost in the minds of the designers when this single-shaft turbojet was planned eight years ago. The first example flew at an initial rating of 3,8251b in the proto- type Gnat in 1955, and the engine has now become virtually a world standard in this thrust-class. The most important versions are the Mk 701 for the Gnat fighters, Mk 803 for the Fiat G.91 family (and licence- produced in Italy and Germany for installation in these aircraft), the Mk 805 for the Japanese Fuji Tl-A trainer and the Mk 100 for the Gnat T.I of the RAF Flying Training Command. The Mk 100 is derated and provided with special equipment to ensure a long and trouble-free life under arduous training duties. The Hindustan HF-24. powered by two Orpheus 703s, flew for the first time last month. Earlier this year Japan placed a repeat order for engines for Tl-A aircraft, and it was announced that a large additional batch of Orpheus is among the items to be supplied to Germany under the agreement between the British and German defence ministers last May. Proteus Also widely employed in industrial and marine applica- tions, this free-turbine engine has flown some 2,000,000hr in Britan- nias in all parts of the world. Overhaul life of the Proteus 705 should soon reach 2,8OOhr, several engines having been examined at this figure; the 750/760 series have lives between 1,350 and 2,000hr. Viper Conceived as a 1,6401b short-life turbojet for missiles and drones, the Viper's principal applications today are the propulsion of trainers and executive aircraft, for which long and trouble-free life is a paramount requirement. The original first-generation aircraft engine was the Viper Mk 101, weighing 5251b, giving a dry thrust of 1,7501b and fitted to the Jet Provost T.3. Its performance and reliability in service has been exemplary, and has facilitated the progressive uprating of the engine, first to the 2,4601b level of the Viper 11 and now to the 3,0001b rating to be established by the new Viper 20. The Viper 11 is in produc- tion for the Jet Provost T.4, Macchi MB.326 and the Jindivik 3 family of targets. The new ASV.20 incorporates mechanical changes so that, in spite of its increased thrust, it remains a conservatively rated engine. Its first announced application is the de Havilland 125 Jet Dragon, and another Viper-powered executive aircraft is likely to be announced shortly. DE HAVILLAND The de Havilland Engine Co Ltd, Leavesden Aerodrome, Herts. Now part of Hawker Siddeley Aviation, this large and versatile company is active in many power-conversion fields, including nuclear engineering. Production of piston engines is concen- trated upon the Queen 70 Mk. 3 rated at 400 h.p.; manufacture of the Major 140 and turbosupercharged Major 215 has ceased, but spares for these engines and for the large number of earlier Queens and Majors, together with the overhaul and repair of Goblin and Ghost turbojets, continues to bring in business on a very large scale. The Spectre 4 is in limited production for the RDS. 15 take-off boost package for the Victor, a large number of Super Sprite take-off packs have been produced for Valiant service, and the RDS.33 Double Spectre powerplant has been delivered in quantity for the Blue Steel test vehicles. Gnome The company have had a technical-interchange agreement with General Electric (USA) since 1951, and early in 1958 an agreement was signed for the production by the British company of the General Electric T58 turboshaft. The Gnome is in no sense a copy of the American engine, but is a natural anglicized descendant which has now branched out into a family of powerplants of major importance. The first British-built engine ran in June 1959, and helicopter versions are now in quantity production against orders placed by the Ministry of Aviation, and by major customers in Italy, Sweden, Ghana and else- where. Distinguished by the prefix H, the helicopter engines have a rear drive from the free turbine, and differ from their American progenitor prin- cipally in having an entirely new control system developed jointly by de .Havilland Propellers (now D. H. Aircraft) and Lucas, and by re- Bristol Siddeley BS.53 Pegasus liftjthrust engine
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
