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Aviation History
1959
1959 - 0796.PDF
20 March 1959 393 NAPIER D. Napier & Son Ltd., London,W.3. Having, as a result of several years' per- sistent slogging, established the Eland andGazelle single-shaft turbine engines as pro- duction products, the past year has been largelydevoted to refinement and consolidation for the exceedingly diverse applications of theseengines. No other aircraft powerplants are currently active projects beyond the brochurestage; extensive development has taken place upon rocket motors (as outlined below) andthe company also designed, developed and manufactured a range of ramjet test vehicles Flight, September 30, 1955) under contract to the National Gas Turbine Establishment. Eland This engine has been developed inthree major versions, for fixed-wing transport aircraft, hub-driven helicopters and the uniqueFairey Rotodyne convertiplane. All three species of engine utilize essentially identicalgas-producer sections. Fixed-uiing As the standard turboprop ver-sion, the Eland 504 is certified by the A.R.B. and F.A.A. and is in production for theCanadair 540 transport for the R.C.A.F. Ver- sions have also been planned for the re-enginingof the Convair 240/340/440, Constellation, DC-6 and other types. Features include anintake heated by oil circulation, a compressor with aluminium-bronze blading, upstrcam-injection burners and a three-stage turbine with stators of X40 alloy, wheels of JessopsH40 and rotor blading of Nimonic 100 (first stage) or Nimonic 90 (second and third stages).Starting is effected either electrically or pneu- matically; the Eland 504A has a Rotax 1-p. airstarter matched to the Palouste 504 G.T.C. set, and the Eland 504B has an AiResearch startersupplied by the G.T.C. 85/62 compressor of the same manufacture. Full type-testing of the Eland 504A for theR.C.A.F. has been completed, and the engine has logged 2,420 hr running in Napier's CV-340and 440. The full anti-icing programme for A.R.B. and F.A.A. clearance was completedwith Napier's Varsity aircraft. The engine has proved its ability to ingest large quantities ofwater, ice and "standard birds" and to contain a broken turbine blade. A 25 hr type test hasbeen conducted while burning Avgas. These engines are expected to achieve overhaul periodsin excess of 1,000 hr by 1960. A version with a higher maximum continuous rating is underdevelopment as the 508. Helicopter A special rear-drive version ofthe Eland designated E.229 has been evolved for the Westland Westminster helicopter, usinga gas-producer similar to that of the turboprop. The propeller reduction gear has been removedfrom the front end, and a gear-type coupling has been added at the rear of the turbine shaft,leading to a ball coupling which accommodates all aircraft and engine axial expansions. Thelatter connects with a drive shaft which incor- porates a second ball coupling and a specialhydraulic clutch. The latter, which is of Napier manufacture, contains two sets of impellerbucket wheels running in engine oil to supply a fluid drive to the rotor gearbox. The engine,hydraulic coupling and primary reduction gear- box are all mounted coaxially, the exhaustgases being ducted away through a lateral jet- pipe. Engine accessories, which include ahydraulic-clutch booster pump, oil-cooler fan and a drive for the aircraft. hydraulic pump,are disposed around the intake and are driven by bevel and spur gears from the compressorshaft. The engine is started by an electric starter mounted above the front end of thecompressor casing. In the Westminster two such engines areinstalled side-by-side. Both are connected to the main rotor gearbox on the centre-line ofthe aircraft, the hydraulic couplings and pri- mary and secondary gearboxes being airfrarne-mounted. Automatic engine control is provided by a single lever for each powerplant, separatecontrols being provided for starting and run- ning up to clutch-in conditions. At presentsome 140 hr have been logged by the Eland 229s installed in the first Westminster. Thedata given beneath the drawing are for the slightly revised Eland 229A which is beingfitted to the second Westminster, and estimated figures are also given for the E.211 which willbe the production Westminster engine. The latter is the variant depicted in the drawing. Convertiplane For the Fairey Rotodyne aunique powerplant has been evolved, consist- ing of a complete turboprop to the rear of whichis attached an additional nine-stage auxiliary compressor which can be driven through ahydraulic coupling to provide air for the rotor pressure jets. Full details of this engine havebeen published previously, as noted below. The current NE1.3 engines of the first Roto-dyne have completed 330 hr installed running; one pair of engines has been in use for over100 hr with only trivial problems. The NE1.7 is a more powerful convertiplane engine cor-responding approximately to the Eland 504. Its total dry weight is 2,575 lb. References: July 23, 1954 (full history,description and cutaway drawing); June 13, 1955 (design philosophy); Dec. 20, 1957 (con-vertiplane version). Gazelle No major changes have takenplace on this powerplant during the past year, and two main versions are in production forthe Westland Wessex (single engine) and Bris- tol 192 (twin engine) helicopters, respectivelyfor the Royal Navy and R.A.F. All Gazelles are designed for installation in any attitude;the drawing shows an engine mounted ver- tically, as in the Bristol 192. Much running has been accomplished in anany-angle cell at Park Royal, and the engine has been proved for tropical operation byemploying electric heaters in the test cell, prior to full tropical flight trials which are shortly tocommence. Total running time is at present approximately 7,800 hr. Some 840 hr has beenrun on NGa.2 engines in a Bristol gantry rig and 116 flight hours have been logged bysimilar engines in the first Bristol 192 to be completed. For the Westland Wessex theNGa.13 has been involved, the chief differ- ences in this engine being the use of "mirrorimage" turbine blading to turn the output shaft in the opposite direction, and a redesignedreduction gearbox to increase the output ratio from 6:1 to 7:1 to achieve optimum matchingbetween engine and rotor r.p.m. Some 277 hr have been logged by NGa.l3s in Wesscxhelicopters. Production engines for both helicopters arebeing assembled at Netherton (Liverpool). B.T.H. and Napier are co-operating in thedevelopment of an i.p.n./cartridge starter for the Gazelle. A large number of failure caseshave been simulated during bench running, and gantry trials have been instrumental insetting the torque trips which prevent the free turbine from over-speeding in the event of aloss of load. Reference: May 10, 1957 (history and fulldescription). Rocket motors After extensive experiencewith the development of single-chamber liquid-propellant motors for missiles and testvehicles, Napier have evolved a family of exceedingly neat H.T.P./kerosinc rocket Napier Gazelle NGa.lJ Military free-turbineturboshaft engine. Eleven-stage compressor, six com- bustion chambers, two-stage compressor turbine andsingle-stage free power turbine- Overall diameter (intake casting), 33.Sin; overall height. 70in: equippeddry weight, 865 Ib; max rating, 1,800 s.h.p. (5-min limit) at 20,400 compressor r.p.m. with s.f.c. of 0.664,or 1,450 s.h.p. (one-hour) at 19,500 compressor r.p.m. with s.f.c. of 0.703. Note: this engine can be mountedat any angle and it shown in the vertical position. Napier Eland 229A Commercial turboshaft engine or rotorcraft. Ten-stage compressor, six combustionchambers, three-stage turbine and hydraulic coupling to rear drive. Overall diameter, 36m; height over oil- cooler blowers, 51in; length as depicted, 135in; dry weight, without rear drive, 1,500 Ib; max rating (2i min),3,150 s.h.p. at 12,500 r.p.m.; one-hour rating, 2,600 s.h.p. at 12,500 r.p.m.; max continuous, 2,400 s.h.p. at 12,500 r.p.m. Corresponding estimated ratings for (he E.211 are 3,500, 2,850 and 2,650 s.h.p. Napier Eland 504 Commercial single-shaft turboprop. Basic layout as for Eland 229. Diameter, 36in; length asdepicted, 116in; dry weight, 1,820 Ib; max rating, 3,230 s.h.p. (3,500 e.h.p.) at 12,500 r.p.m. with mass flow of 35.5 Ib/sec, pressure ratio of 7:1 and s.f.c. of 0.57 Ib/hr/e.h.p.; cruising rating at 20.000ft at 300 m.p.h., 1,635 s.h.p.(1,800 e.h.p.) at 11,750 r.p.m. The Eland 508 has a similar performance, although the max continuous rating is raited from 2,670 s.h.p. (2,910 e.h.p.) to 2.860 s.h.p. (3,110 e.h.p.).
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