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Aviation History
1956
1956 - 0005.PDF
6 January 1956 Fairchild's S.T.O.L. THE accompanying general-arrangement drawing depicts anS.T.O.L. (short take-off and landing) design, a prototype of which—designated M-232—is at present being constructed by theAircraft Division of the Fairchild Engine and Airplane Corpora- tion, of Hagerstown, Maryland. The concept has been generallyworked out by Mr. W. E. Hunt, of the Wiggins-Hunt Engineer- ing Corporation, who hold a joint patent for the design withMr. E. A. Blonquist, of New York City. In the early 1930s Mr. Hunt had been engaged in the design ofthe Crouch-Bolas Dragonfly, a well-known slow-flying biplane in which almost the entire wing area was subject to slipstreamfrom two large airscrews. Previously the same technique was patented by Dr. A. Zahn (1917), although in this case there wereno fewer than five lifting surfaces, one above the other, and three airscrews. A generally similar principle—that of makingthe entire wing subject to slipstream—was employed in 1940 in this country by both Airspeed, Ltd., and General Aircraft, Ltd., intheir designs of fleet shadower aircraft. Both these designs were fully slotted and flapped, and were powered by four Pobjoyradial engines distributed evenly along the wing. In the new Fairchild, power is provided by a pair of buriedLycoming SO-580 piston engines, which pass some 800 h.p. to a gearbox and drive-shafting incorporating over-running clutches.The 13ft-diameter airscrews, placed well ahead of the wing and tilted slightly downwards, have provision for pitch variation andflapping after the manner of helicopter rotors. In the take-off configuration much of the air handled by the airscrews is deflecteddownwards through a considerable angle by the wing, which has full-span slats and trailing-edge flaps. It is intended ultimatelyto make the airscrew axes variable in order to satisfy the require- ments of take-off and cruising flight. One obvious disadvantage of such layout is that the design of the airscrew blades cannot be that for peak efficiency in bothslow-speed and cruising flight, particularly in view of the fact that Fairchild are aiming at a cruising speed considerably greaterthan 200 m.p.h. General stability and control problems at low airspeeds will also be acute, a particular difficulty being theachievement of an adequate smooth airflow over the fixed tail surfaces. The consequences of failure of the transmission shaft(either on one side or on both sides) would also seem to be disastrous at low air speeds. Nevertheless, this is the first timethat a completely integrated design of this nature has been trans- lated into metal, and flight trials may, in fact, show that suchaircraft combine many of the virtues of the helicopter without the attendant shortcomings in performance and high operating cost.The prototype is rapidly approaching completion and should certainly fly before the middle of this year. The work is beingfinanced by Fairchild. Fairchild M-232 experimental short take-off and landing aircraft poweredby two Lycoming SO-580 flat-eight piston engines driving airscrews through shafting: Span, 39ft; length in flying position, 29ft 6in; length of nacelle,18ft 4in; distance between centre lines of airscrews, 17ft; ground angle, 25 deg (landing) or 22 deg (take-off). Maximum weight, 7,000 Ib; accommodation,pilot plus passenger; also provision for belly nacelle accommodating eight men or four stretchers. Short-field requirement, to be able to use 500ft clearing with 50ft-high surround; cruising speed, 242 m.p.h. PROFESSOR G. T. R. HILL IT is with deep regret that Flight has to record the death ofProf. G. T. R. Hill, M.C., M.Sc, M.I.Mech.E., F.R.Ae.S., whose name will always be associated with the Pterodactyl tailless aircraft. He died in Londonderry at the Christmas week-end after several years of ill health. He was 60. Prof. Hill had taken up farming after his retirement, in 1954, from the post of chief aero- nautical consultant to Short Bros, and Harland, Ltd. Geoffrey Terence Roland Hill was educated at University College School and University College, London. While he was still in his early teens he achieved prizewinning credit as a builder of model aircraft, in which pursuit—and subsequently in the construction of a near-successful full-scale glider—he shared the enthusiasm of his brother, who was later to attain fame both as an aeronautical artist and as a senior officer of the Royal Air Force —Air Chief Marshal Sir Roderic Hill. After obtaining a B.Sc. in 1914, G. T. R. Hill joined theRoyal Aircraft Factory as a graduate apprentice. From the outset the practical side of flying attracted him even more stronglythan the theoretical, and by 1916 he had obtained a commission as a 2nd lieutenant in the Royal Flying Corps; he fought inFrance with No. 29 Sqn., was awarded an M.C., and was later invalided home with the rank of captain. Test piloting attractedhim, and by 1918 he was in command of the Aerodynamics Flight at Farnborough. When the war ended he went toHandley Page, Ltd., as their chief test pilot, and in 1919 took Prof. Hill with the Pterodactyl Mk. la. The heading portrait was taken in more recent years. a W.8 up to nearly 14,000ft—aworld record for an aircraft of 1,500 kg all-up weight. Even in the earliest days at Farn-borough, Hill had been gravely concerned at the phenomenonof stalling, and its results; and the thought which he had devoted tothe problem crystallized in the design of the Pterodactyl, whichhe first flew as a glider in 1924 and with an engine a year later. Impressed by the design, theWestland company undertook to develop it, and Capt. Hill joinedtheir organization. During the next seven years, five marks of Pterodactyl appeared, of increasingsize and power; the last, the Mk V of 1932, was a two-seater fighter powered by a Rolls-Royce Goshawk, weighing 5,100 lbwith military load, and capable of 190 m.p.h. at 15,000ft. Throughout the series Hill's object had been—in his own words—"to try to design an aeroplane which would never, through an error on the part of the pilot, get out of control." Between the wars, academic distinctions began to come hisway, and in 1934 he was appointed to the Kennedy Chair of Mechanical Engineering at University College, London. Fiveyears later he was seconded to the Air Ministry, and subsequently to the Ministry of Aircraft Production, for special research work.In 1942 he acted as a scientific liaison officer between the British and Canadian Governments. At the end of the war he acted as a consulting engineer, notablyto Short Bros, and (in 1947-50) General Aircraft; in 1948 he retired from his University College chair, but continued with anumber of activities in Ulster; he was a special lecturer to Belfast Technical College, and president of Belfast R.Ae.S. branch. The final years of Prof. Hill's career brought no diminutionin his ability as a designer. Just as the problem of the stall had occupied him in earlier days, so did he now bring his analyticalmind to bear on the problems surrounding the control of high- speed, high-altitude aircraft. His approach was the aero-isoclinicwing, the aerodynamic and structural behaviour of which are such that the incidence at any section remains constant in the face ofdeflections caused by flight loads. In order to test this wing an ad hoc aircraft, the Short Sherpa, was prepared. A particularfeature of the Sherpa is the use of rotatable wing-tips for both lateral and pitching control—in a manner not unlike thatemployed on Hill's Pterodactyls.
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