bluuebunny/crossref_metadata_2025_split huggingface dataset:
The cost definition phase of a new commercial aircraft programme
Authors: Loeken W.G. 
Published: March 2023

A commercial aircraft programme has always been an undertaking with significant risk. Accurately estimating potential sales and production costs of these aircraft is an essential part of containing this risk. This paper addresses the cost estimating process and cost management of the latest Boeing programme — the 757.Substantial resources are required for a new programme. The number of people involved, of course, varies with the stage of production, but Boeing will employ approximately 10,000 at peak production rates. In a typical Boeing programme, a network of over 1000 suppliers of material, parts and equipment will employ another 20 000 people at peak production so that total employment is in the 30 000 range.
Hydrodynamics and aerodynamics — cross fertilisation in research and design
Authors: Pearcey H.H. 
Published: March 2023

Hydrodynamics and aerodynamics start as one science and retain an extensive common base, including, for example, a wealth of fundamental theory and observation of streamline flows, boundary layers and vortical motions, (Plate 1).But research and design have opened up the two frontiers in different directions, to support and often to lead the evolution and development of the respective fields of application — ships and aeroplanes, or ships and helicopters, or helicopters and other marine structures.We are reminded of how far the helicopter has become an integral and indispensible part of the maritime scene and of so many maritime operations, and this is one of the best tributes to the great pioneering genius, drive and enthusiasm of Raoul Hafner who is very much in our minds as we consider the possibilities and prospects for cross fertilisation.
Low cost aircrew training devices
Authors: Knight M. A. G. 
Published: March 2023

The purpose of this talk is to describe some of the more simple aids used in the training of aircrew and to illustrate how they can be integrated with flight simulators and aircraft to form a systematic approach to aircrew training. Of course, low cost aids do not solve all training problems, neither can they replace the aircraft or the flight simulator for many tasks, but they are worth examining for reasons which will appear in this paper.As a start, it might be useful to look at a typical flight simulator and note some of its characteristics as a teaching device.
The micro revolution comes to civil air transport
Authors: Ryland Mark 
Published: March 2023

The microprocessor revolution can in no way be described as a ‘silent’ revolution, unusually perhaps, a technological advance has caught the imagination of the mass media, who are fond of postulating its effect on our lives.Within the Air Transport industry much coverage has been given to the development of ‘visibly’ different avionic equipment such as cathode ray tube (CRT) flight instrumentation, active control technology and flight management systems. These advances have been made possible solely on account of the microprocessor, which has, in addition, also revolutionised existing avionic disciplines.
Peaked velocity profile generation
Authors: Laws E. M. 
Published: March 2023

Morgan and Saunders have shown that highly peaked velocity profiles can be produced in a pipe downstream of a partial gauze screen, a screen pierced by a central hole. By systematically varying the ratio of hole size, d, to pipe diameter, D they obtained peaked profiles with different values of profile peakiness û/ū.The investigation showed that two different velocity profiles with the same value of û/ū. could be produced from a particular gauze, one from a screen with d/D <0·5 and the other with d/D>0·5.
A user’s view
Authors: Lucking A. J. 
Published: March 2023

Though billed as an honorary consultant to the Air Transport Users Committee, I must underline that I speak for no one but myself, as irritated BEA advocates used to point out to the Air Transport Licensing Board in the old days.The airline user is concerned with the real price of his ticket, or freight invoice, though he realises that this is related to the cost of producing the service. His complaints are first, that the fare structure is often unfair, and furthermore fails to maximise the revenue earning opportunity: and secondly, many airlines’ staff costs are far too high.
Practical application of the rapid frequency sweep technique for structural frequency response measurement
Authors: White R. G. , Pinnington R. J. 
Published: March 2023

SummaryThe rapid frequency sweep technique is the result of a considerable amount of research into the development of a transient method for the rapid measurement of structural frequency response, digital data analysis procedures being used to derive the required dynamic characteristics. Theoretical analyses, together with the results of experimental studies and experience gained during structural testing are presented here which illustrate practical considerations and limitations of the method; these range from discussion of exciter attachment, effects of transducers and choice of instrumentation to signal processing methods and related criteria. A simple guide to practical structural testing is given in the final section which outlines procedures to be followed during testing and signal acquisition.
The aircraft manufacturer’s approach to airworthiness
Authors: Troughton J. , Grigg R. 
Published: March 2023

Airworthiness — fitness for flight — is one of the main factors influencing aircraft design. This joint paper discusses the problems of managing airworthiness and some of the methods used in an aircraft design organisation dealing with new and development designs and ‘in service’ aircraft.External standards of airworthiness are set by many national and international authorities and it is vital that the aircraft manufacturer plays his part in setting these standards so that the implication on operational economics and production liability are considered. In addition the manufacturer sets his own internal standards of airworthiness. The relationship between civil and military airworthiness requirements are reviewed.
A supersonic V/STOL fighter design project
Authors: Fielding J. P. 
Published: March 2023

The College of Aeronautics performs an annual group design project as a major part of its Aircraft Design MSc programme. Projects are chosen to be representative of current areas of interest and the programme is carried out in a manner which is as close as possible.to that of aircraft manufacturers.Vice Admiral Forrest S. Peterson, Commander Naval Air Systems Command, said at the AIAA/NASA-Ames V/STOL Conference in 1977 that:V/STOL appeared to be the most effective, most economical means of addressing many of our major military needs: dispersal of air assets over a broad geographic range, reducing the present reliance on relatively few ships and large permanent bases and reducing the cost of maintaining an adequate, efficient air arm.
Cost control of aircraft manufacture a modern approach
Authors: Jackson E. T. 
Published: March 2023

Bonus schemes have tended to fall into disrepute and have been neglected; this is a pity because they are an extremely powerful tool when applied successfully. One of the weakest areas of the individual bonus scheme for cost control was the setting of standards through individual negotiation influenced by many factors, rather than by estimating the work content.During 1975, the individual bonus scheme was suspended at British Aerospace Weybridge-Bristol Division, Filton Site, and a start was made on the development of a cost control system based on work measurement and using modern computing techniques. The new system had to contain two essential features. First, the speedy identification of jobs giving problems on the shop floor, since it was realised that the suspension of the individual bonus scheme would slow down this process, secondly the provision of a fast and reliable method of checking the work issued to the shops against the original estimates.
Initial design of stringer stiffened bend boxes using geometric programming
Authors: Snell M. B. , Bartholomew P. 
Published: March 2023

SummaryThe technique of geometric programming is applied to the design of optimum wing bend boxes in sheet-stringer-rib construction. The work extends the previous application in multi-spar design and the results for the different configurations are compared. Closed-form design equations are given for the case of buckling constraints whereas more complex formulations with stress constraint were solved by computer.
Noise research
Authors: Cheeseman I. C. 
Published: March 2023

The development of the jet engine produced jet noise problems. Most of the understanding of jet noise was and is performed in universities. The fundamental and quite exceptional work of Lighthill was followed by that of Curie. Powell and Ffowcs Williams at Southampton in the early 1950s and was paralleled by experimental investigations on noise suppression by for example. Lilley at Cranfield. This university work was used to form the basis of a programme of research into jet engine noise at Ministry of Aviation establishments with considerable university inputs which established a commanding lead for the United Kingdom in the understanding of jet noise.The formation of the Institute of Sound and Vibration Research at the University of Southampton under the inspiration of Professor E. J. Richards was a step which placed university research at a different level to that usually observed in the United Kingdom by concentrating in one place some 40-50 people all devoted to research and postgraduate education.
Structures and materials
Authors: Davies G. A. O. 
Published: March 2023

Universities should be able to do two things which industry may not be able to do, and which should be valuable. We are supposed to be able to have time to think instead of continuously meeting deadlines (this is hardly true anymore) and so we can:
1.Take a risk and embark on a novel idea which may not come off. If the gamble works then we publish and promote it for the general good.2.Recognise that industry has to meet deadlines, and often produce an answer to a problem which is only partially understood. We can then look at the problem in depth, and with better understanding point the way to future development.
Development of European Avionics Standards — 20th Anniversary of EUROCAE
Authors: McWiggan T. J. 
Published: March 2023

The role of the International Civil Aviation Organisation (ICAO) in developing standards and recommended practices for communication, navigation and surveillance systems is well known. The emphasis is on system characteristics and the definition of airborne equipment is limited to essential characteristics. For many years, the world’s airlines have collaborated in the Airline Electronic Engineering Committee of ARINC to produce engineering characteristics to ensure interchangeability and hence freedom of choice in their selection of airborne equipments. Thus ‘box’ dimensions, types and pin connection, interfaces cabling, coding etc are covered.For the electronics industry designing equipment to meet the needs of both the aircraft constructors and their customers, the airlines and the Airworthiness Authorities responsible for the certification of equipment installed in passenger carrying aircraft more detailed specifications are essential. This problem was recognised in the USA and a solution was found in the formation of the Radio Technical Commission for Aeronautics (RTCA). With the direct support and involvement of USA Government Departments, the Electronics and Aircraft Construction Industry, the Airlines and General Aviation operating as ‘Special Committees’ of experts, RTCA developed Minimum Performance Standards. These documents are used by the FAA as the basis for equipment certification.
Saving fuel with the wide-chord fan
Authors: Cundy John 
Published: March 2023

More than ten years of development have gone into the Rolls-Royce wide-chord fan, which will provide a 2½ per cent fuel saving when it enters service in 1984. This new and highly efficient fan is one of the advanced features of the 535E4 engine, which will have a fuel consumption 10 per cent better than that of the initial Rolls-Royce engine for the Boeing 757, the 535C.How has this advanced fan been developed and what are its advantages? This article surveys the reasons for its development and the factors involved in this technical advance pioneered by Rolls-Royce.
Digital simulation of counterspun nutation damper operation under non-ideal operating conditions
Authors: Clements R. R. , Wright J. H. , Tonkin S.W. 
Published: March 2023

SummaryPrevious analysis of the operation of the counterspun nutation damper has been restricted to small nutation angles and to axisymmetric spacecraft. This paper develops equations for the dynamics of nutation damper/spacecraft combinations in which the spacecraft is non-axisymmetric and may adopt large nutation angles. In addition, a mechanism to model the growth of nutation due to energy dissipative mechanisms on board the spacecraft is introduced.The dynamic equations were programmed in a digital simulation language. The effects of three probable imperfections in the construction and operation of nutation dampers on the operating characteristics of the dampers were investigated by simulation. The implications of these non-ideal conditions for the design of counterspun nutation dampers are identified.
A note on the representation of bimodal distributions
Authors: Campion M. C. 
Published: March 2023

Reference 1 provides the stimulus for this note, containing, as it does, a trap into which many engineers and statisticians fall. Referring to Fig. 6 of that paper (this was incorrectly labelled — it should have been Fig. 4), a set of observed data is presented on normal probability paper, together with a straight line representing the fitted normal distribution. Since none of the points is far from the line, the conclusion is drawn that the data are well-fitted by a normal distribution.However, a closer look at the figure shows that the scatter of the ‘observed’ points about the fitted line is not random, but systematic; the first four points all lie above the line, the next six below the line, the next eight above the line, and the last two below the line.
A vectored-thrust rotor for helicopter anti-torque applications
Authors: Molyneux W. G. 
Published: March 2023

SummaryA rotor concept is described that enables the generation of a controlled thrust vector in any direction within the rotor’s sphere of action. It is suggested that a rotor of this kind might replace the entire tail unit of the ‘conventional’ single-rotor helicopter to provide a lighter, more compact layout of improved performance. An active control system might be required for the ‘flying-tail’ layout envisaged.Some of the structural and mechanical design problems that are posed by a vectored-thrust (VT) rotor are briefly discussed and are seemingly tractable by exploiting the potential of advanced composite materials.No assessment is made of the aerodynamic performance of a VT rotor, nor of the helicopter configurations or operational scenarios where a VT rotor might prove advantageous. Some limited assessments of this kind seem merited.
Observations on the highly coned propeller
Authors: Molyneux W. G. 
Published: March 2023

SummaryThe unique aerodynamic features of the highly coned propeller, with cyclic and collective control of blade pitch, are discussed in simplistic terms.The configuration poses severe structural design problems and, while fibre reinforced composites fabrication might enable these to be surmounted, there will be weight penalties in overcoming them that will limit potential applications.No outstanding prospect for the propeller is identified, but specialised applications may merit a closer scrutiny of the concept.
A combat aircraft mission readiness model
Authors: Burleigh C. D. , Fielding J. P. 
Published: March 2023

It has always been important for military commanders to be able to rely on their equipment being available to them during a conflict. Some recent published figures, however, showed that two modern fighter aircraft were only available for missions for 47% or 56% of the time.A simple operation simulation model was derived to show an aircraft's sensitivity to the main availability parameters. This model can be applied to any aircraft type provided that the necessary inputs can be calculated. The simulated operations were as realistic as possible, although many assumptions had to be made.For reasons of national security it was not possible to relate this study directly to any current service aircraft, so a design project study has been used as the baseline aircraft in the simulation model. This aircraft was the 1980 Mini-CAS, developed at Cranfield Institute of Technology. This was used because all the necessary data were available or could be estimated with reasonable confidence and also the operating conditions are comparable to a number of current service types employed in the Close-Air-Support role. Thus the simulation was kept realistic and the results and conclusions are directly applicable to real and projected designs. Subsequent work checked the validity of the model by simulating an A-10 exercise and Sea Harrier operations in the Falklands conflict.The Operations Simulation Model proved to be a satisfactory means of assessing the effectiveness of a force of aircraft under war-time conditions. It was far more flexible than the Availability and Mission Readiness equations commonly used to compare the in-service performance of aircraft and highlighted areas where resources could best be concentrated to improve availability. Further improvements are necessary however, to take account of spares shortages and the effect of adverse weather.
The flow development in a shielding jet
Authors: Baker J. N. 
Published: March 2023

SummaryThe flow from a high aspect ratio rectangular nozzle has been studied, so as to provide data to aid prediction of the effectiveness of this type of jet flow for acoustic shielding. Flow parameters investigated in both stationary and parallel, coflowing, airstreams, include axial centre-line velocity decay, jet width growth and velocity profile similarity. The existence of significant velocity peaks towards the edge of the jet in the plane of the major axis was observed, together with an unexpected interaction on this jet flow by an adjacent circular and subsonic jet.
The next European engine for combat aircraft
Authors: Lewis G. M. 
Published: March 2023

European Aero Engine Companies assisted by National Research Establishments have a long and successful record in the design, development and manufacture of engines for high performance military fighter aircraft.Because the cost of developing and producing a new aero engine is now so great, it has become increasingly impracticable for individual European nations to embark on such projects alone. This has resulted in recent years in a number of collaborative European engine programmes. As Fig. 1 shows, the range of European military turbofan engines now in service is largely the result of such collaboration amongst various European countries, and compares with the much more limited US involvement in design collaboration. Figure 1 also shows that the thrust range covered by European military turbofans is very comparable to that of engines of US manufacture.
The von Karman Institute for Fluid Dynamics — Teaching and Research
Authors: Ginoux Jean J. 
Published: March 2023

As a member of the International group who set up the von Karman Institute for Fluid Dynamic (known at that time as the Training Centre for Experimental Aerodynamics — TCEA) Professor A. D. Young participated actively in the Institute's programme. After the death of Dr von Karman in 1963, he was nominated Chairman of the VKI Board of Directors, and still holds this position.It is clear that the goals of the Institute, as envisaged by Dr von Karman, have been successfully met. After the first few challenging years under his leadership, it was essential to ensure that the scientific reputation of the Institute continued to be strengthened. The VKI is now recognised as a major establishment in its own right with a very high scientific reputation.
World Civil Aviation in Chaos
Authors: Taneja Nawal K. 
Published: March 2023

This short note is intended as a measure of thanks to Alec Young for his encouragement and supervision of the author's PhD studies.International air transport is a vital industry, integral to world trade, commerce and tourism. This industry has contributed substantially not only to worldwide economic growth, but also to political and sociological progress. However, in recent years the industry has fallen into chaos, to the point that many airlines find themselves either subject to unstable situations, or threatened by bankruptcies, or, in the case of state-owned airlines, in need of financial support from their governments. Competitive behaviour sometimes occurs on an under-the-table basis, interline co-operation has been deteriorating, and a clear international policy whose guidelines are accepted by everyone in the industry is absent. If the international airline industry is to continue to play a vital and dynamic role in contributing to the progress and prosperity of so many nations, then it is essential to adopt and implement policies aimed at eliminating the chaos in the industry, facilitating its healthy growth and stability, and developing international collaboration for the common good.
On the design of three-dimensional wind tunnel contractions
Authors: Downie J. H. , Jordinson R. , Barnes F. H. 
Published: March 2023

A method is given for the calculation of incompressible inviscid flow through non-axisymmetric contracting ducts with rectangular cross-sections. The method is based on a finite difference approximation to Laplace's equation and solved by the method of successive over relaxation. In an attempt to provide practical criteria for the design of such contractions, the flows through a series of contraction shapes were calculated, each shape being based on a pair of matched elliptic arcs. This permitted choice of such parameters as length, local (ie two-dimensional) contraction ratio, position and magnitude of the maximum slope. It was found that reducing the length of the contraction also reduced its effective length, although increasing the effects of overshoot and undershoot. This could be compensated for by designing a contraction with a steep maximum slope which with associated low curvatures at entrance and exit reduced the values of overshoot and undershoot. The axial positions of maximum slope on wall and roof should be the same.The predictions of the numerical method were tested against experiment and, in general, satisfactory comparisons were obtained.
Some effects of sweep direction and strakes for wings with sharp leading edges
Authors: Poll D. I. A. , Qiu Cheng-Hao 
Published: March 2023

SummaryAn experimental investigation has been carried out to compare the effects of sweep direction upon the aerodynamic characteristics of three wing planforms. The wings have biconvex aerofoil sections which allow them to be tested in both the forward-swept and backward-swept configurations without changing the section profile. Measurements of lift, drag and pitching moment have been made for angles of incidence in the range —5° to +50° at a mean chord Reynolds number of approximately 1·5 × 105 and a Mach number of 0·1. To complement the force and moment data a comprehensive series of oil-flow visualisations are also presented. In addition the aerodynamic characteristics of simple strakes (wing root fillets) have been studied for both the swept-forward and swept-back configurations.