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THE Society of Automotive Engineers' paper, upon which this article is based, followed very closely along the lines of an article entitled ‘Composite Power Plant System for V/S.T.O.L. Aircraft’ published in the December, 1962, issue of AIRCRAFT ENGINEERING [see Ref. (4)]—although the latter paper concentrated upon a description of the RB. 162 and the use of lightweight lift engines for a V/S.T.O.L. low‐level strike fighter. The S.A.E. paper has therefore been slightly condensed here, to avoid unnecessary duplication and a number of illustrations have been omitted. Throughout this paper there are references to the advantages of a multi‐engined aircraft for the V/S.T.O.L. fighter application in preference to the single‐engined type. These passages must be read in the light of the recent statement to the effect that Rolls‐Royce have submitted to the Ministry of Aviation design proposals for a version of the Hawker PA 154 V.T.O.L. aircraft powered by two lift/thrust engines based upon the Spey by‐pass engine. These two lift (thrust engines would replace the single Bristol Siddeley BS.100 vectored thrust engine which is believed to have a thrust (with plenum chamber burning) of about 30,000 lb. Apart from the more obvious advantage of having two engines, i.e. safety, and the ability of the aircraft to complete the mission as a conventional aircraft if one engine fails, there is also the additional and attractive proposition that the Rolls‐Royce Spey engine is already in quantity production for a number of civil and military aircraft and could presumably be readily adapted to a lift/thrust configuration with front nozzle incorporating plenum chamber burning and rear nozzle. Finally, the reader is recommended to study in full the articles referred to in Refs. (2), (3), (4) and (5), in addition to this paper, since these provide a comprehensive survey of the jet lift field and in particular the application of jet lift to V/S.T.O.L. fighters. The six references listed on this page did not, of course, form part of the original S.A.E. paper—Editor.

THE rate of progress in civil aviation during the last decade has been largely determined by engine development. When the jet engine was first used in civil aircraft it was a means of obtaining higher speeds and improved passenger comfort at the expense of high fuel consumption and considerable annoyance to airport communities because of the noise. Significant improvements in fuel consumption and noise were obtained when the bypass concept was introduced, but there was a pause in development while the value of bypass ratio remained at about one. Another major forward step is being taken with the ‘new technology’ engines of bypass ratio five or more now under development, and it is timely to review the influence of these engines on the design of short range civil aircraft.

Our report on the Paris Air Show takes the form of an introduction, information on highlights and an overall impression of what is thought to be of most interest to our readership.

Based on a lecture prepared as part of the celebration of Cranfield University's 50th anniversary. After briefly reviewing the early years, including Cranfield University's entry into this technology, discusses the nature of this industry, Some of the technology drivers, including environmental concerns, are examined to provide a background against which the development and the future of the industry can be considered. This is followed by a brief survey of some of the possible new civil aero gas turbine applications over the next 50 years, both the very likely and some curiosities. Finally, the changes that are likely to occur within the industry as a result of wider economic and political trends are considered, as well as the implications for those working within the industry. The development of the civil aero gas turbine has contributed, in large measure, to today's, US$ 300 billion civil aviation industry and is rightly seen as one of mankind's major engineering achievements. A single paper cannot do justice to this industry.

Normalair‐Garrett Ltd., (Stand No. N31) part of the Westland plc Group of Yeovil, Somerset, is exhibiting a wide range of products which demonstrate the company's diverse capabilities in control systems and precision components for the aerospace industry.

This study aims to explore the viability of using C-17 reduced-engine taxi procedures from a cost savings and capability perspective.

This study model expected engine fuel flow based on the number of operational engines, aircraft gross weight (GW) and average aircraft groundspeed. Using this model, the research executes a cost savings simulation estimating the expected annual savings produced by the proposed taxi methodology. Operational and safety risks are also considered.

The results indicate that significant fuel and costs savings are available via the employment of reduced-engine taxi procedures. On an annual basis, the mobility air force has the capacity to save approximately 1.18 million gallons of jet fuel per year ($2.66m in annual fuel costs at current rates) without significant risk to operations. The two-engine taxi methodology has the ability to generate capable taxi thrust for a maximum GW C-17 with nearly zero risks.

This research was limited to C-17 procedures and efficiency improvements specifically, although it suggests that other military aircraft could benefit from these findings as is evident in the commercial airline industry.

This research recommends coordination with the original equipment manufacturer to rework checklists and flight manuals, development of a fleet-wide training program and evaluation of future aircraft recapitalization requirements intended to exploit and maximize aircraft surface operation savings.

If implemented, the proposed changes would benefit the society as government resources could be spent elsewhere and the impact on the environment would be reduced. This research conducted a rigorous analysis of the suitability of implementing a civilian airline’s best practice into US Air Force operations.

Major technical advances were featured at the Show, particularly those developments that will be coming into service in the very near future. An outstanding demonstration was given by the Airbus Industrie A 300B2 Fly‐By‐Wire (FBW) whose autopilot simulates the control laws of the A 320. The pilot flies the aircraft through the FBW autopilot using the sidestick controllers as in the A 320, which is due to make its first flight in March, 1987. A convincing display by the A 300 FBW began with a slow fly‐past in landing configuration with gear and flaps down at a speed of about 100 knots. At mid‐runway position, the crew simulate a windshear encounter and the captain pulls back on the stick as might happen in such a situation. In a standard ‘conventional’ aircraft, this would lead to a stall with potentially disastrous consequences, but with FBW the pitch angle increases to the point where the wing reaches its maximum lift position and stays there. The ‘alpha‐floor’ protection incorporated in the aircraft then automatically increased engine power and the combination of maximum lift and power results in a climb‐out at 3,000ft/min. In another manoeuvre, the aircraft is positioned at an angle of attack of 15.5° in order to stabilise speed at 95–100 knots and only just below the limit of 17° — 18°. Also demonstrated was a stall turn with the nose up to maximum angle of attack and bank angle of 30° which stops there despite the fully‐deflected stick position. The engine power in this manoeuvre is controlled manually.

SINCE man first aspired to fly the desire to take‐off and land vertically and to hover in flight has always presented a challenge to the engineer. To date only the rotary wing aircraft has achieved these aims in service but their shortcomings in terms of speed, range and economy have encouraged engineers to search for more elegant ways of achieving vertical flight.

This paper aims to set up and assess a new method to collaboratively mature the requirements for engine development in a more efficient way during the preliminary design phase.

A collaborative process has been set up in which detailed information on the behaviour of designed engines has been integrated into the aircraft preliminary sizing process by means of surrogate modelling.

The engine surrogate model has been invoked as a black box from within the aircraft preliminary design optimisation loops. The surrogate model reduces the uncertainty of coarse-grain formulas and may result in more competitive aircraft and engine designs. The surrogate model has been integrated in a collaborative cross-organisational workflow between aircraft manufacturer, engine manufacturer and simulation service providers to prepare for its deployment in industrial preliminary design processes.

The new collaborative way of working between aircraft manufacturer, engine manufacturer and simulation service providers could contribute to remove time consuming rework cycles in early and later design stages within delivering the optimal aircraft-engine combination.

The assessed process, based on an innovative collaboration standard, provides the opportunity to introduce useful design iterations with much more enriched information than in the classical design process as performed today. Specifically, the application of an engine surrogate model is advantageous, as it allows for extensive trade-off studies on aircraft level because of the low computational effort, while the intellectual property of the engine manufacturer (the engine preliminary design process) is respected and kept in-house.

THIS paper is not intended to provide any startling revelations of Soviet technology but is a detailed survey and analysis of contemporary developments in Soviet turbine powered transport aircraft. The major portion of the work is based on Soviet sources of information in an attempt to assure authenticity and accuracy.