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Aviation History
1944
1944 - 0457.PDF
JWL\RCH^2~XD, Topics of the Day [U/^ F LIGHT 237 $iiii|>lil*i<*a1ioii and Safety More About Planned Control Layouts : The Need for the Careful Segregation of Important Items ; "Practical Untidiness": Why Not Automatic Undercarriage Retraction of High^efficiency Types 1 • DURING the last year or two there has been a com fortingly increasing desire amongst designers of engines and airframes to simplify the work of the pilot, but it almost begins to seem at times as if " auto matics '' are being overdone in rather the wrong direction. Instead of designing an aircraft so that an intelligent pilot is helped to make the best use of his limited number of hands and feet in harassing situations^ffhe experts art, tending to give him aircraft which. caJTbe handled satis-* factorily even by a well-trained anilwiftxtrous moron. More than once I have enlarged 0^1 thl neadsfor cont, simplification and standardisation, and l*vf made good and bad suggestions in an attempt to nap eattli, designers to visualise the sort of things trat ar/jpreeded. Nothing very much has been done on th<SsW>«flles—lines that are considered by the pilot to be the mo|t^mportant of all—and yet quite a lot in the little matters of engine control for maximum economy and efficiency on long flights. Not that' these lines are good or that it isn't vitally important to make an engine foolproof in the way of pre venting the pilot from using weak mixture at rated boost, for instance, or from leaving the mixture control in "weak" while coming in to land, or from exceeding the permissible maxima in boost and revolutions. That had been done before, with constant-speed airscrew stops an 1 lever-trip mechanisms. But completely automatic mixture arrangements, auto matic blower-engagement devices, and automatic revolu tion-setting systems do not strike me as being quite is necessary or useful as any possible system by which the take-off drill, to mention only one thing, can be simplified. While only just airborne the pilot must then go through a series of movements which may even involve changing the ©ontrol-hand and which always involves a good deal of juggling; yet, later on, when he has all the time in the world to think about things, his simple little engine-control setting jobs are now done for him. As I've just said, the •^present-day aircraft appears to have been designed more For the benefit of the ambidextrous moron—the pilot who can be taught to go through a series of complicated move ments with his hands and feet, but who is not considered intelligent enough to use his weak mixture control properly, or to change the blower gear at the right sort of altitude. Cockpit Drill Surely the cart has been put before the horse? It 's easy enough to train someone in the essentials of engine handling—and, anyway, a large notice can always be pasted up somewhere in the cockpit so that the most moronic individual, except when involved in combat, couldn't fail to do things in the right way. But a great deal of concentrated training is necessary before any human being has mastered the intricacies of the take-off and approach "drill " on different types, with the various con trols placed, as they so often are, in the most awkward positions. Speaking for myself, I would much rather be left lx> look after blowers and mixture controls in my own good ftne, and an entirely automatic mixture system quite often involves a "flat spot" in the throttle range where the mixture is too weak for the boost in use—with a consequent rise in engine temperatures if this part of the throttle movement is not studiously avoided. But that is by the way; I'm not complaining about the "automatics" already introduced, which are undoubtedly for the best in the best of all possible worlds, but about the lack it " automates " and sometimes even of intelligent planning in matifers which 1, at least, consider to be more vital. Th^igh their layouts are usually good, if only in a therfetical sort of way, American aircraft are the worst qjrenders so far as overloading a harassed pilot with " drill" (B concerned. It is not so very long since the pilot oi an jPwacan aircraft had to deal with a progressive type oi nvtt^ control, and he still, more often than notyhad ro ski* off with one eye.on the boost gauge, and ata third throttle, because no automatic boost control was fitted. And there are always, in American ships, about three more points to deal with before the take-off, quite apart from the seemingly unnecessary " switchery" littering the place. One usually, for instance, has to switch on the battery and the electrically operated instruments, as weil as to fiddle about with the series of ingenious tumbler switches which operate the doping system and the inertia starters. Since the aircraft is not yet on the move, with temperatures going up and green lights being impatiently flashed by flying control, these items are not a worry and the layout certainly has its good features. But no well- designed aircraft should need' a tail-wheel lock (which one furiously engages while already bowling down the run way), and even fjief booster-pumps have not been found to be really necessary in British aircraft with comparable take-off power outputs "and consequent high fuel con sumption. One can get used to anything, and my con tention is merely that it shouldn't be necessary nowadays to need to get used to any purely mechanical actions which can be simplified without great difficulty. Layout Compromise And even if further simplification is not practicable, it should be possible, in the early stages of design, to ensure that all the essential controls and switches are specially segregated, and so placed that they can be easily reached. British aircraft, for all their apparent untidiness to American eyes, are usually quite good in this respect, thougk even the "quite good" can always be improved, "phe "fact, that one can get used to, and even learn to prefer, any layout in the world is no excuse for slackness. 1 know that in some aircraft lack of space is a serious prob lem, and the designer, with the help of the prototype test pilot, can only do his best; that "best" should always be towards segregation, if nothing else can be done, leaving all the less important items to find their own places. A few months ago I flew a certain American type for the first time, with no one to show me the "taps." I found that the battery and instrument switches were in the middle of a host o>"6thei switches of less importance, and I had to obtain the services of a fitter to show me the posi tjon of the magneto switch after a prolonged and fruitless search. From any normal seat position this switch was actually hidden from view below a ledge! The under carriage selector lever, I found, could only be reached when the Sutton harness catch had been released—so one eithci had to take off with this essential safety device disengaged (at the very moment when one needed it most), or struggle to release the catch, with the undercarriage still down, during the most significant and dangerous moment of the flight. If the engine stops just after take-off one has the choice of leaving the undercarriage down and going ov< i
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