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Aviation History
1957
1957 - 1045.PDF
26 July 1957 WS-125A. This U.S.A.F. specification concerns a nuclear bomberaircraft with a cruise endurance measured in days, even with pro- tracted supersonic operation. G.E., who have extensive industrialnuclear experience, are one of the two prime powerplant contractors for this system, and are teamed with Convair San Diego, who areresponsible for the airframe. The company are working on an open-cycle layout, the closed-cyclesystem having been assigned to Pratt and Whitney. Air from the turbojet compressor is passed through the reactor itself, so forming acompact heat-exchange system which eliminates intermediate systems involving special liquids or gases. The resulting powerplant should beappreciably lighter and more powerful than corresponding closed- cycle units. G.E. have been concentrating on systems in which a single reactorprovides heat for multiple turbojets. Most rig-running has been carried out with a quartet of hack units comprising the compressor and turbinesections of J73s with the combustion systems removed. The J73 cluster is disposed around the reactor and coupled to it by ductingso that air from any one compressor is led through an individual path within the reactor and then admitted to the nozzles of the turbineof the same engine. At the A.E.C. testing station at Arco (Idaho Falls) this cluster has conducted 600-hr runs at t-i. temperatures of 1,400deg F (implying about 1,800 within the reactor). Assuming maximum r.p.m. one derives a mass flow of 600 lb/sec and a theoretical thrustof some 35,000 lb. This work is obviously far removed from any powerplant capableof installation in a supersonic aircraft. From it is being evolved the X-211 open-cycle system which is intended for use in the first aircraftbuilt to the WS-125A specification. As the aircraft design is obviously completely dependent on that of the powerplant, work on the airframeside of the project has recently been decelerated. G.E., however, are in a strong position, since X-211 has been awarded more than halfof the $200m which remain to be spent in this field in the current financial year. The strength and pace of X-211 development is beingincreased by transferring men from conventional turbine work. Additional to this work Convair themselves have for many monthsbeen flying a 1-MW research reactor in an NB-36 aircraft. This pro- gramme is intended to evaluate materials in radioactive environmentsand rest the shielding of structures, crew and systems. WS-202A. Under this specification, issued by the U.S.A.F. last year,North American Aviation are developing a long-range piloted inter- cepter for service from 1965. Initially it will operate at Mach 5 at200,000ft, and (it is said) the final vehicle is intended for flight at Mach 10 at some 550,000ft. The first generation of this family willhave air-breathing powerplants (probably four) developed from the engines of the WS-110A. High-energy chemical fuel will probably beused from the start, and flow-velocity and temperature will far exceed anything previously associated with gas turbines. Rocket Motors. A pioneer in the field of large rocket motors, G.E.have several important contracts for the propulsion of test vehicles, a typical research programme being that of the RV-A-10 for the develop-ment of very large solid-propellant motors. Large G.E. rocket motors are proved at the Malta test station, N.Y. General Electric X-405. Rocket motor. Single-chamber rocket motor for propulsion of first stage of Vanguard satellite-launching vehicle. Gimbal-mounted chamber fed by turbopump with liquid oxygen and petrol (with alcohol and silicone-oil added). Length as depicted, approximately 70in; thrust, about 27,000 Ib; specific impulse, about 240; efflux velocity, about 7,780ft/sec. One of the biggest commitments is the propulsion of the first stageof Vanguard, the 72ft, 11-ton vehicle which will launch the earth- satellite for the International Geophysical Year. Development of theX-405 motor has posed arduous problems; during the early stages last year failures were frequently caused by the long burning time and itwas rare to obtain more than 70 sec operation. The specified burning time is 141-150 sec. The motor runs on the unusual combination ofliquid oxygen and a mixture of approximately 95 per cent petrol, four per cent alcohol and one per cent silicone oil for cooling. It has beensuggested that later versions of X-405 may employ liquid ozone as the oxidant, but in view of the tight development schedule this couldhardly be introduced at present. The motor has now reached the flight- test stage and should be highly developed by the end of the year. HERRMANN. Herrmann Engineering Co., 1405 Air Way, Glen-dale 1, California. Extraordinarily simple in design and likely to develop into a reliable aircraft engine worthy of serious attention, the cam engineunder development by this company has now been issued with an Approved Type Certificate by the C.A.A. The principal features aredescribed in the data; extensive bench testing has been done and the company are in a position to attract sales. Since the completion oftype-tests the compression ratio has been increased to 9 : 1 and 225 h.p. is being achieved; changes in timing and intake-valve size are expectedto bring this up to at least 250 h.p. 135 Herrmann Model 375. Cam engine. Twelve cylinders housing six double-ended pistons located by rollers on a swash-plate cam on the main shaft. Poppet valves actuated by corns on the main shaft. Diameter, 18in; length, 5O.5in; bore, 3.25in; stroke, 3.75in; swept volume (four strokes per revolution), 373 cu in; dry weight, 264 Ib bare, 337 Ib with dual ignition, starter and generator; maximum rated power, 210 h.p. at 1,900 r.p.m. Progressive increases in power are anticipated. HILLER. Hiller Helicopters, 1350 Willow Road, Palo Alto, Col.For seven years Hiller Helicopters have been developing small ramjets for helicopter tip-drive applications. The unit depicted in the drawingis fully certificated; the life is at present more than 150 hr and produc- tion units power the Hiller H-32 light helicopter. Hiller are also anxiousto licence-produce S.N.E.C.M.A. pulsejets for use by the U.S. Army in such unusual tasks as lifting bridge-sections into position. Hiller 8RJ-2B. Subsonic ramjet for helicopter tip-drive. Simple steel-sheet duct with central injector and flame- holder comprising radial, rearward- sloping fingers. Overall diameter, 8.4m; overall length, 21.2in; weight, approximately 12.7 Ib; typical thrust at 662ft/sec, 39 Ib; overall s.f.c, 10.2. LYCOMING. Lycoming Division, Avco Manufacturing Corpora-tion, 550 S. Main Street, Stratford, Conn. Concentrating on air-cooled engines of relatively low power, this company have built up a highreputation during their 29 years in the aero-engine business. Many thousands of piston engines have been manufactured for aircraft, heli-copters and a variety of ground applications, and the company are now entering production with the first of a family of versatile small shaft-turbines. As the latter are having to compete directly with reciprocat- ing engines, Lycoming have had to evolve a formula for minimizingthe cost of design, development and production while allowing each powerplant to retain sufficient flexibility for it to be acceptable overa wide range of aeronautical and surface applications. The company have undoubtedly succeeded in this task and have broken new ground inso doing. Development and manufacture of a wide range of flat-four and flat-six piston engines is proceeding intensively, and a completely new unit is described below. In addition, Lycoming have for several yearslicence-produced the Curtiss-Wright R-1300, rated at 800 h.p., and the R-1820, rated at 1,425/1,525 h.p. The former, a seven-cylindersupercharged unit, is mounted diagonally in late-model Sikorsky S-55 helicopters and horizontally in the Vertol HUP-4. The latest R-1820shave many applications, including the Vertol H-21 and Sikorsky S-58 helicopters (in all their variations) and are also used in the GrummanAlbatross and S2F/TF/WF series of aircraft as well as in the North American T-28, Hurel-Dubois H.D.34 and the Learstar. All respon-sibility for these engines in the U.S.A. is now vested in Lycoming. Since last lear's review of their work, Lycoming have flown theirfirst gas-turbine, the T53, and have announced the more powerful T55. The Gas Turbine Department has grown to a personnel strengthof more than one thousand and is steadily acquiring additional space and equipment. Across the street from the main plant is the company'sflight test establishment at Bridgeport municipal airport. Here Lycoming are conducting their own trials of the T53 in a KamanHOK-1 helicopter, the work being carried out under contract to the U.S. Army. The flight test establishment will also be used for fixed-wing engine development. Another new facility for which ground has been broken is the model engine service centre located at the airport atWilliamsport, Pa., which is believed to be the only centre of its type in America devoted to small aircraft engines. Apart from engines, the Lycoming Division's aviation activities arevaried and well established. Sub-contract work, a major part of their business, has been progressively expanded during the past twelvemonths. One of the most interesting contracts concerns the manufac- ture of the 48in nozzle housing for the Curtiss-Wright RJ47 ramjet,powerplant of the Navaho. The first units to this contract were de- livered last winter. Other work includes the design and developmentof parts for B-50 tanker conversions, major components of the air- turbine-driven alternators and hydraulic packs of the B-52, precision-machined parts for the J57, J75 and J79 engines, hydrospin com- ponents for guided missiles, precision-machined parts for Sikorskyhelicopters and manufacture of the bulk of rotor components for the Vertol H-21. Total Lycoming employment at their two plants at Stratford andWilliamsport is approximately 9,000. A new divisional president, James R. Kerr, was appointed on May 1 of this year. T53. Vice-president (turbine engineering) of Lycoming is Dr.Anselm Franz, who until 1945 was responsible for the design of gas turbines for Junkers A.G. Now an American citizen, Dr. Franzgathered a staff of six at Lycoming and in 1951 began to investigate the general field of small shaft-turbines. Early in 1952 a design-studywas submitted to meet a joint Army/U.S.A.F. requirement for a "flexible" turboshaft engine of 600 h.p., principally for helicopterapplications. It was no mean achievement for the embryonic team at Lycomingto win the competition in July 1952, against 13 other companies. In spite of their lack of experience and facilities the Lycoming team,which had then grown to 25, began parts-fabrication in the summer of
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