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Aviation History
1946
1946 - 1164.PDF
598 FLIGHT JUNE 13TH, 1946 of controls which, to the ordinary person, can be some-what unnatural. But this much-stressed landing difficulty is far lessprominent a source of error than that of judging a final approach. Whereas a pilot who has put ina few hundred hours on different types can more or less guarantee a fair, if not actually a good land-ing on anything, the same pilot, even after a couple of thousand hours, is still never quite sure of himself duringthe approach. He has learnt, by a complicated process of visual judgment and trial and error, to know whether he is tending to undershoot or overshoot at any particulardpoint during the approach, INOI bU blMrLt but he never learns enough master control. Its use in instituting turns or in correct-ing aileron yaw is quite subsidiary to that, when helped by fuselage keel-surface, in losing height and/or speed atwill. In the days when the Widgeon originally appeared, the motoring approach was unknown, flaps had still notbeen seriously invented, and arrivals were deliberately arranged so that there was always a couple of hundred feetstill to be lost over the boundary. By the use of very coarse top rudder, this height could be lost quite instinc-tively, but in a performance which, to-day, would look sus- piciously like dangerous flying. In those times people were forced, by the very nature of the aircraft, to make the g not to find himself in one or other of these positions. There are, obviously, so many variables present during the pro- cess that perfection can only be temporarily attained when exactly the same aircraft is being flown in entirely similar conditions hour by hour. Even when, with the help of a tricycle undercarriage, limited elevator control, and a system of control-linkage, the aircraft has been arranged so that an entirely inexperi- enced driver should find no difficulty, under ideal condi- tions, in parking it unbroken, this same driver can still run into the most outstanding trouble while making an approach. It will require at least as much practice time to learn to deal with these troubles, through steadily im- proved judgment, as it would to learn to land some difficult and old-fashioned contrivance with three separate controls and somewhat tricky characteristics. And the person who has learnt to fly in the box-kite will be in a very much, better position, at any hourage figure, when bringing an aircraft in across wind or on to a runway. Even if the pilot has been taught to apply instinctively the requisite amount of skid to counteract the drift, it may not be possible to hold any simplified " the-air-for-all" device in the appropriate attitude. Even the best tricycle under- carriage cannot accept an unreasonable amount of drift. Yet one-way strip-landing conditions, in which the greatest trouble is likely to be experienced, are just those which the ordinary private-owner is most likely to meet. A machine which can only be safely landed into wind on a fair surface is obviously not going to be of very much use for day-to-day travels in all conditions and in the hands of absolute amateurs. In most simplified control arrangements the modification has involved either the removal of the rudder control, or its combination with some other. Perhaps this has been because the rudder, operated in conventional aircraft by the fe'et, is the most difficult of all to master, or, maybe, because this control, in present-day designs, needs to Tae used for little more than yaw-correction. Ancient and Modern 1 found it interesting, therefore, a few weeks ago, when I had the opportunity of flying two types which were just about as dissimilar as they could possibly be. The first was a light aircraft of the old type, while the second was one of ^he "new" kind, in which control simplification had gone as far, in my opinion, as is reasonably possible with present airframe layouts. The first—none other than our old friend the Westland Widgeon, and possibly the only one of its type still flying —is a parasol monoplane with the kind of characteristics which were accepted without question in the 'twenties and 'thirties. While aileron and elevator control reactions were more or less normal by present-day standards, the rudder effects were of a calibre not to be met in many modern types. In spite of the fact that the Widgeon has no appre- ciable fin area, the aircraft is directionally stable and it is possible to hold it indefinitely in a side-slip or skid of the 30-degree-off-straight calibre. In fact, to watch Mr. Pen- rose, the Westland chief test pilot, doing his worst with this old war-horse took one back to the golden age of air- craft. With this kind of machine the rudder is, in fact, the U N I.) maximum and accurate use of the rudder in combination with the other two controls. The '' modern '' aircraft, which I flew a- few days later, , was the Miles M.48—which is virtually a "one off" ex- ,"** perimental version of the M.38 Messenger. In this the rudder, though adequate for normal purposes, can fairly be described as being for incidental use only. In all ordinary circumstances the pedals can be ignored. Rational Controls Perhaps this reduction in the status of the rudder is what is needed in the way of rational simplification ; the control is available for essential purposes, but is not all- powerful and need not be moved with any accuracy. Obviously, other means of varying the engine-off approach angle must be provided, and the use of variable degrees of lift flap and (in the case of the M.38) of plain drag flap provides the necessary control. For a conventional lay- out, a type like the M.38 has probably reached something very near the limit, too, in stall-proof possibilities. If further simplification is really required, it would seem that a useful line of attack might be that of control ration- alization in the cockpit rather than of any modification of the surfaces. Since we already have aircraft which are virtually '' two-control'' in their handling, but which still have a rudder available, it might be possible to organ- ize the system so that the movements are more natural. Before the war something of this kind was tried in the Hordern-Richmond, a light twin-engined type in which all three surfaces were moved by a single control. A column, which moved in the usual way to operate the elevators and ailerons, was surmounted by a wheel controlling the rudder. In the Chrislea Ace prototype the designer has done much the same thing, but, in this case, he has given the wheel the possibly more natural function of aileron control. Rudder movements are made by a pivoted side- to-side action of the horizontally mounted stub column, while the elevators are controlled by an up-and-down move- ment around the same fulcrum point. Certainly, a pilot brought up on a conventional aircraft could not cope immediately with the Hordern-Richmond, and it remains to be seen whether the reversal of the rudder-aileron functions of the wheel, coupled with the special movement of the '' column,'' will make the entire action more natural both for the trained pilot and the newcomer. Even if the Chrislea arrangement does not~, after all, prove to be satisfactory from the pilot's pointsK of view, it seems that there might still be a good deal inthe idea of devising some all-in-one system which is so natural in action that one's untrained reflexes are the im-mediate and automatic translation of one's wishes. FORTHCOMING EVENTS June 15th.—Old Cranwellian Assoc. reunion, R.A.F College. June 15th.—No. 150 Sqn. R.A.F. reunion dinner, Dor- chester Hotel, 6.30 p.m. June 17th.—The Royal Society's Empire Scientific Con- ference opened by the King in London University 11 a.m. June 18th.—Aero Golfing Society (Flight Trophy), Wey- bridge. June 19th.—Sir Frederick Handley Page at Gauge and Tool Makers' Assoc. luncheon. Savoy, 12.30 p.m.
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