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Aviation History
1940
1940 - 1525.PDF
MAY 23, 1940 Topics of the Day 477- THE TIME HAS COME " Indicator " Has More to Say About Control Layouts and About a Perhaps Distant Future ONE day, I feel, the manufacturers would do wellto call a meeting of test and ferry pilots so thatthe whole question of the standardisation of a con- venient control layout may be thrashed out. Nowadays the word ' standardisation'' is rather more important than "convenience," since the majority of modern types have, through the efforts and criticism of works test pilots and others, become reason- ably rational. Furthermore, though it is occasionally necessary to carry out a sort of fast sleight of hand trick with undercarriage, throttle and airscrew controls immediately after the take-off, one becomes accustomed to anything, and a pilot who habitually flies one par- ticular type will probably refuse to hear a word against the layout which has become second nature to him. But for ferry pilots, at any rate, the infinite varia- tions and combinations can be a very present source of trouble, and a standardisation scheme would be worth while from the production costs point of view. There are, of course, one or two standard control boxes, but these, though excellent in themselves, can cause more trouble even than scattered Heath Robin- son arrangements when the' various manufacturers decide that the different levers shall have very different purposes. It is comparatively easy to remember that the Excraft fighter has its undercarriage and flap selec- tor on the right and the airscrew control above the throttle on the left, that the Whycraft long-range bomber has the whole lot in one place, or that the Zedcraft medium bomber has the pitch controls behind the undercarriage control on the right and below and the petrol cocks almost out of reach on the right. Conducive to Confusion Those are sufficiently different to be easily remem- bered. The real difficulty arises when exactly similar or similarly placed controls have totally different func- tions. For instance, there are two types in which exactly the same control box and layout is used, with the controls reading in rows from left to right and from front to rear respectively (and as far as I remember) as follows: (a) Throttles and mixture controls; super- charger, carburettor heater and constant speed airscrew controls; cut-outs ; balance cock and main petrol cocks, (b) Constant speed airscrew and throttle controls ; petrol cocks and cut-outs combined, supercharger control and mixture lever; carburettor heater control. Admittedly, the majority of these controls need only to be looked at and handled before leaving the ground, but in the air and at critical moments it might be pos- sible to move airscrew controls instead of throttles, mix- ture levers instead of airscrew controls, supercharger controls instead of carburettor heater controls, and petrol cocks instead of supercharger controls. The ferry pilot expects to be caught out and is therefore ready to read- just his mind to each type, but imagine the effect on a pilot who is thoroughly accustomed to one type only and placed, without warning or time for preliminary ground practice, in the control cabin of the second type. To quote a few examples, it is equally disastrous to attempt to take off with the blower control in its high- speed position, with the airscrew controls in full course, and with the mixture controls in "weak." These things could happen, though, for instance, the mixture controls cannot usually be moved with the throttles in the closed position or will spring back as soon as they are opened. The uninitiated might imagine that an even better take.off and climb (though with deleterious effects on the power units) can be obtained by using the high-altitude blower speed. In fact, ;A ground level atmospheric pressures, the power taken by the supercharger when turning at high speed, is a good deal greater than that obtained through the higher effec- tive compression ratio. The majority of the latter must also and necessarily be lost through preignition and so forth. Things, in fact, are not at all what they seem. ::••.- ?-. Automaticity ; ;; It might almost be possible and reasonable to go to the extreme of arranging all essential controls so that they move to the correct take-off position as soon ws the throttles are opened. Such a system would demand a cut-out so that the principle would not be applied when running-up on test, when making an approach or when using full throttle in level flight. A large indicator could be used to show the pilot whether the machine was " in automatic " or not When the throttles were opened with " automatic " in action, the hydraulics would be turned on, the trimming tabs properly adjusted, the mixture moved to rich, the pitch control adjusted to "fine " and the flaps to " up " or take-off position. A stop on the throttle would prevent it from being moved with the petrol cocks off or the indicator lights out. Such a scheme may sound complicated but it is no more so than anything else, and much less expensive than one broken aeroplane. While on the subject of standardisation—and remem- bering that there will, eventually, be a peace—it should be possible to design bomber and long-range reconnais- sance types so that they can, without ruining their essential military features, be converted to carry pas- sengers and/or mail. That, I feel, is something worth trying in the case, particularly, of really large types. On no account must development be delayed, but an additional section of any design staff can be working on the problems involved while the machine is still in the drawing-board stage. If these " conversion " experts are late with their modifications, then, of course, the design must go through as a purely military type. Defence and offence requirements make compromise absolutely impossible in sizes which are at present used. I am thinking more of the sometimes maligned " flying fortress " type of thing. Such items as turrets, dustbins, bomb traps and long-range tanks do not require such basic planning as size increases. That, at least, is how it appears to the semi-technical and partially informed insider. No doubt certain sections of the lay Press would, if they saw such a suggestion in print, accuse me of having dealings with this strange, new and largely mythical thing known as the Fifth Column. It would not be diffi- cult to show that I was attempting to sabotage produc-
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