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Aviation History
1957
1957 - 0054.PDF
54 FLIGHT Research, Development and Technical Issues . . . on electronic techniques which are, to a greater or lesser degree, vulnerable to electronic interference. Improvements of a few per cent, or even hundreds of per cent, makes little impact on a million- fold advantage. Much has been made in pubhc debate of the high-explosive ground-to-air guided weapon as an antidote to this position, but it is difficult to feel happy with the argument. There are available to such weapons, in principle, no devices of a special kind for ensuring end-point accuracy or lethality that are not available to fighter aircraft, and the choice of whether or not to replace the pilot by automatic devices should be seen as one of many technical decisions involved in creating a weapon rather than, as seems to have been the case with some commentators, an issue in itself. As an issue it is a relatively minor one from the technical point of view. The overriding factor is the million- fold increase in offensive power. This will, no doubt, eventually be offset by the use of nuclear explosive for air defence and such a development may well make a more powerful impact on the dominance of the bomber and ballistic missile, and hence on the political results that stem from that dominance, than any other single factor. While these consequences of developments in long- range aviation are going on, the initial impact of military aviation on the land battle will not have diminished in importance; indeed, the more successful the policy of the global deterrent becomes, the less likely it is to be employed, and the more likely does it become that means will be sought to "get around the flank." In a world which must increasingly recognise the interdepend- ence of countries' vital interests, and realise that advance in the standard of living for all is best achieved by ensuring that the contribution that each can offer, whether in terms of special goods or of special facilities, is available to others, transport aviation for people and for goods will have a decisive contribution to make. The military side of aviation is an essential guard for stability; the civil side an important means of exploiting this stability for the common good. APPENDIX (.see page 19, Pan 2) The Range and Economy Equations. The general performance of an aircraft that spends a large part of its flight in a cruising condition in the stratosphere is contained in the equation WLF where R=gross cruising still-air range. ( TT j —lift/drag ratio in the cruise. V= cruising speed. . c=specific fuel consumption of the engines. Wo=total weight at the start of the cruise. WLF=weight of the aircraft less its fuel. This equation applies to any type of propulsion, if the power- plant performance is converted to an equivalent specific fuel con- sumption, and to any configuration of aircraft, provided it flies at constant lift/drag ratio. Defining the "operational fixed weight equipment" as the sum of the earning payload, the crew, and the equipment of fixed weight necessary for the canduct of the mission, the weight-less- fuel (H^LF) of the aircraft is the sum of the weights of the "operational fixed weight equipment" and the weight of those items that are dependent on aircraft size, such as structure, power- plant, and systems. The range formula thus relates these weights by the expression We , WB = ~ WJD) Wo + Wo 6 where Wc=weight of the operational fixed weight equipment. WB = basic weight =W$ + Wp + Wu Ws, Wp, and Wu are the structure weight, the powerplant weight and the miscellaneous systems weight respectively. Wc ~ can be loosely described as the fractional payload. The Wo "earning" payload is less than Wc by the weight of the crew and fittings for the mission. The data contained in this equation can be plotted in the formshown in Fig. 6 where -ry, LjD, .-— Wc r^r- are related. The range needed (R), the speed proposed (F) and the specific con- Rr sumption (c) available, fix —, which is then related to the line marked with the LID expected, on the left hand plot; horizontal transfer to the right hand plot then produces the relation between WB J Wcand A rough approximation to the direct operating cost of a long range civil aircraft is given by P= R Wl + V We where P — direct cost in money per ton mile. A and B are constants. We = earning payload, which is We less an allowance for crew and non-earning fittings. WB = basic weight. The first term covers fuel costs, whilst the second covers such items as depreciation, maintenance and crew salaries, which are roughly related to the basic weight of the aircraft. In most cases of interest, to the accuracy needed for exploratory work We is not greatly different from WQ, and B ~ V Wo \A (Wv Wc IR \W The weight ratios are obtainable from Fig. 6. Such approxi- mate costing is not, of course, suitable for detailed work but it is good enough to gain an initial impression. (This cost formula is due to Mr. Thome of the Royal Aircraft Establishment.) TRAFFIC CONTROL AT WISLEY AIRFIELD A SPECIAL air traffic control installation has recendy beencompleted at Wisley, Surrey, by International Aeradio, Ltd. The equipment was fully engineered in the I.A.L. workshops at Southall, Middx, so that installation was completed with a mini- mum of dislocation to existing services. In the main control room at Wisley, which is the chief flight test centre of Vickers-Armstrongs (Aircraft), Ltd., the former con- trol desk has been replaced by an I.A.L. twin-position one. Com- munication on six V.H.F. channels is provided, audio for three being fed to the left-hand desk-panel speaker and the other three to the right hand. Both positions are provided with R/T. control panels. Control of these six channels is also available to two approach- controllers in the radar room using individual R/T. control units, and to a D/F. operator using a transmitter control unit designed to fit into a V.H.F. D/F. console. These three positions are served by three associated loudspeakers in conjunction with a muting unit. The receiving and amplifying equipment is housed in two 6ft cabinets, with the six receivers in one and the microphone and loudspeaker amplifier equipment in the other, in a room next to the control room. A third cabinet, containing six transmitters, is at the base of the transmitting mast. On the air-traffic control desk there are also meteorological indicator instruments, and selector panels for the recorder and for traffic-light control. The former allows selection for tape-record- ing on any channel; the latter controls the two sets of traffic signals on a road crossing the runway. Wisley handles production and development test-flying of Valiants and Viscounts, and flight trials of the Supermarine N.113 are carried out there. The scale of activity is indicated by the fact that Vickers-Armstrongs (Aircraft), Ltd., employ twenty test pilots, most of them based at Wisley. The new I.A.L desk in operation at V/isley, as described above.
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