The interaction of an incident oblique shock wave with the turbulent boundary layer with suction is investigated. Wall streamline and schlieren photograph visualisations as well as the pressure measurements on the wall are made. Boundary layer surveys with pressure probes and hot-wire probes are also done. The suction downstream of the interaction almost nullifies the shock reflection while the higher suction up and downstream of the interaction results in a reflection similar to that in inviscid flow.

There is a popular misconception that synthetic training is only concerned with time spent in the simulator. If this were so, a training exercise which had focused on the simulation experience alone, might fail to provide the rich learning environment needed to maximise training opportunities and so fall short of expectations in terms of delivery of a complete training experience.

This is particularly true when considering collective training for military aircrew; where all mission phases are equally important, and all roles and tasks must be carefully considered when assessing the training need. The training designers must create a scenario that meets the requirements of the total training audience (the collective) throughout all the mission phases; planning, briefing, flying (traditionally the key simulation event) and debriefing. This scenario must allow the trainees to become fully immersed and provide a ‘total experience’ in order for them to obtain maximum benefit from the synthetic training event.

Maintenance of such an environment during the training process places an extra burden on those who are providing the training experience. As the number and mix of trainees participating in a synthetic exercise grows so too do the demands placed upon the exercise management team, the trainers and the assessors to provide a rich and rewarding training experience. Not only must these key personnel be carefully selected, their needs must also be taken into account during the training design process. This will help to ensure that transformation of data to information and information flow is optimised for all participants.

Recent experience in mission training via distributed simulation has shown that greater training opportunities can be afforded if the training designers address the needs of all the above. Using these experiences as reference points, this paper will discuss synthetic training issues along with the expectations of the trainees and the training providers and suggest some guidelines for creating a total training experience.

Throughout the world helicopters are being operated in a variety of roles today and, whereas ten years ago, there was not one type which had got beyond the stage of being an inventor's plaything, several types are now suitable for regular military and civil operations. At present, so far as is known to the author, public transport services using helicopters are confined to charters and scheduled mail services, with the exception of a scheduled passenger service which has been run by the British European Airways Corporation as an operational experiment since June 1950. The factors, both technical and economic, which have so far prevented the large scale introduction of public transport helicopter services, are being progressively overcome and in due course operators will find that manufacturers have made available suitable aircraft. The operators' task will then be to fly these aircraft in a safe and regular manner and give the public the best service possible.

The effects of the model surface to free stream adiabatic temperature ratio (Tw/Tad) on periodic transonic flow over a 14% thick biconvex aerofoil are evaluated using a computational fluid dynamic approach. The analysis is based on the thin layer Navier Stokes equations with Baldwin-Lomax turbulence model. The results of computations showed that on biconves aerofoils there is a large effect of heat transfer on instantaneous pressure distributions and periodic buffet excitation level confirming some of the available experimental data. The effects observed have an implication in wind tunnel measurement of buffet associated periodic transonic flows.

When an aircraft lands on a runway on which there are extensive puddles, it appears that sometimes the water exerts a large upwards force on the wheels, so preventing them from making contact with the ground. The wheels are then said to “aquaplane”. In the aquaplaning condition the braking effectiveness of the wheels is reduced virtually to zero, and even at touch-down speeds insufficient to cause aquaplaning, when there is some contact between the wheels and the ground, water on the runway may cause appreciable reductions of runway friction forces. This note offers some tentative suggestions concerning the nature of the water flow when aquaplaning occurs, and is put forward as a basis for discussion of this important practical problem.

In 1949 F. H. Pollicutt, in the course of a discussion on a paper presented by P. B. Walker to the Royal Aeronautical Society, reported fatigue test results which indicated that when the aluminium alloy conforming to specification D.T.D.364 was tested, under , axial loads, in the form of Z-sections, its fatigue properties were extremely low. Z-sections with unmachined surfaces and even Z-sections with completely machined surfaces failed after short endurances at stress ranges under which small polished round test pieces would not have failed even after hundreds of millions of cycles. Pollicutt, in discussing these low values, advised that great caution should be exercised in their interpretation, warning equally against an unqualified acceptance of the testing technique and a too facile acceptance of small polished round bar test results.

This paper aims at developing an aeroelastic model for the instability analysis of supersonic thick fins. To this aim the modal analysis technique is used for the structural dynamics modelling of a fin with a general structure. An unsteady aerodynamic model is applied based on the shock/expansion analysis over the flat surfaces of the fin along with local application of the piston theory. Assuming a supersonic fin with an arbitrary polygonal cross-section, thickness and initial angle-of-attack, the steady flow properties (e.g. Mach number, density and temperature) are calculated over the flat surfaces of the fin. Then, assuming small amplitude vibrations, the generalised aerodynamic forces are obtained in terms of the structural modal coordinates. Using the obtained model, the effect of thickness, initial angle-of-attack, taper ratio and sweep angle on the aerodynamic derivatives and aeroelastic stability of the fin are studied which show their remarkable effects on the instability Mach number and its type. Specially, the presented results show that increasing the fin thickness dramatically diminishes the stability margin mainly at low angles of attack. Also a sharp decrease of the divergence Mach number is observed by increasing the fin’s incidence angle.

Accidental dispersals of medically and agriculturally undesirable insects by sea and air transport are discussed, with attention to the relative importance of the roles of ships and aircraft. World-wide records of insects found on board aircraft and discovered to have been introduced at airfields are briefly reviewed, and consideration is given to ways of meeting the problem by insecticidal treatment and airport insect control. It is felt that the insecticidal treatment of aircraft, even when provided for by comprehensive international regulations and conscientiously undertaken, does not alone provide sufficient protection against insect introductions, and that greater attention should be paid to the preventive aspects of the problem, with particular regard to the control of insects of both medical and economic significance at international airports.

Virtual Engineering (VE), also known as Model-Based Systems Engineering (MBSE), is necessary in both current operational engineering qualifications and to help reduce the costs of future vertical lift design and analysis. As computational power continues to provide increasing capability to the rotorcraft engineering community to perform simulations in both real time and off line, it is imperative that the community develop verification and validation protocols and processes to certify these methods so that they can be reliably used to help reduce engineering cost and schedule. Computational Fluid Dynamics (CFD) has become a major Computational Science and Engineering (CSE) tool in the fixed wing and vertical lift communities, but it has not been developed to the point where it is accepted as a replacement for testing in certification of new or existing systems or vehicles. Since the rise of modern CFD in the 1980s, the promise of CFD’s capabilities has been met or exceeded, but its role in certification arguably remains less prominent than projected. The ability to implement transformative technologies further drives the need for CFD in design. To meet CFD’s role in certification, several goals must be met to provide a true “numerical experiment” from which accuracies (error estimates), sensitivities, and consistent application results can be extracted. This paper discusses the progress and direction towards developing CFD strategies for certification.

An experimental investigation to determine the effectiveness of a wing-tip device designed to attenuate the trailing vortex of a lifting, flat-plate wing is detailed. The induced-breakdown vortex attenuation device (IBVAD) is essentially a toed-in, vertically-oriented sheared tip. Results are presented comprising force-balance, water tunnel flow visualisation and wake studies using a seven hole probe. The data shows that compared with an equal span rectangular wing, variations of the IBVAD device can reduce drag at moderate-to-high lift coefficients, as well as reduce die maximum rotary velocity of the trailing vortex by 28%. Axial vorticity in the wake vortex was significantly attenuated compared with the rectangular wing, with a 52·6% reduction in the magnitude of die maximum vorticity. The vortex core radius was also seen to be larger than die rectangular wing. However, even substantial attenuation and redistribution of trailing vorticity may be insufficient to reduce the wake hazard.

The Fortieth Wilbur Wright Memorial Lecture, “ Prophecy and Achievement in Aeronautics,” was given by Sir Harry Garner, K.B.E., C.B., M.A., F.R.Ae.S., before the Royal Aeronautical Society on Thursday 29th May 1952 at the Institution of Civil Engineers, Great George Street, S.W.I. Mr. G. H. Dowty, F.R.Ae.S., President of the Society, presided over the meeting which comprised some 350 members and guests.

Medals and Prizes awarded by the Council for 1951-1952 were presented before the Lecture.

This paper deals with the methods of physical modelling of Flight Control Systems (FCS) by means of Dynamically Similar free-flying Models (DSM) for the investigation of stability and controllability of aircraft at subsonic flight speeds. The subsonic flight regime allows us to avoid Mach number similarity considerations. The large scale of the DSM meets autosimilarity of Reynolds numbers, whilst Froude similarity is assured during the development and manufacturing of the DSM. This paper proves the presence of necessary and sufficient conditions of similarity for the FCS of an aircraft, and that of its DSM. The existence of necessary conditions have been proved both mathematically (by means of the π – Theorem from the theory of dimensions), and with equations involving physical quantities. The generalised scale coefficients for transitioning from the FCS’s aircraft gain factors, to those of the FCS of the DSM have been obtained, and it is shown that the coefficients depend only on the linear scale of the DSM.

This paper discusses selected aviation human factors challenges in the air transport environment. Because of the authors’ background, much of this paper will be based upon the growth of human factors and airline training in transport aviation in the United States. However, parallel growth and advancements have been made in other parts of the world from the beginning of air transport and are being made in many parts of the world today. This is certainly true of Great Britain. One should never forget that air transport is a world enterprise and has been since its beginning. While it is important to recognise that cultural and other differences should be considered if they are relevant, it is equally important in air transport to recognise that common problems are solved by common solutions and can be addressed by, but are not limited to, common approaches.

It is recognised that the behavioral aspect of aviation human factors deserves considerable attention, particularly in the area of training and evaluation. We have also learned that previous training criteria are not satisfactory for operation with increasingly complex aircraft being operated in an increasingly complex environment. Human errors occur with greater frequency than is often believed and can be made by anyone — even an airline captain. An inevitable consequence of this entirely human characteristic is that the role of the co-pilot has been considerably enhanced. Furthermore, the monitoring function of the pilot-not-flying, whether he/she is the captain or co-pilot, is now recognised as a critical safety function by virtually all serious operational experts.

A comparison has been made between the composite beam designs produced by minimum mass optimisation using two different sets of constraints. The first approach constrained the design to have a given separation between fundamental bending and fundamental torsional natural frequencies; the second constrained the design to have a given flutter and divergence speed. The beams are modelled as a series of elements, stepped in thickness at discrete nodes, with the Dynamic Stiffness Method being used for calculation of their natural frequencies. The aeroelastic constraints are obtained from the Fortran program CALFUN. The results show that for similar flutter and divergence speeds, the optima produced using aeroelastic constraints have a slightly lower mass (up to 4% lower) and a less ‘hard’ flutter onset. However, the time taken to produce these optima is significantly longer (in excess of 2 orders of magnitude). A preliminary study discusses the merits of a combined optimisation method where frequency constrained optimisation is used to provide a near-optimum starting point for flutter and divergence constrained optimisation. In addition, a wind-tunnel model of one of the optima has been manufactured and subject to both modal analysis and wind-tunnel tests to validate the flutter speed calculations. This shows that when using strip theory, CALFUN predicts a conservative value of flutter speed for this design. Further investigation has shown CALFUN's lifting surface theory to be more accurate for low aspect ratio models.

In view of the increasing awareness of the population to noise pollution, reduction of aircraft noise annoyance to an acceptable level becomes one of the necessary conditions for the acceptability of aircraft operations close to populated areas. In particular, reducing the subjective acoustical annoyance of VTOL aircraft to the surrounding community should become the common objective of aircraft manufacturers, airport planners, potential aircraft operators and the community itself if the latter is to benefit from all the possible advantages of VTOL service.

The evaluation of rotorcraft performance and handling qualities in piloted flight using a desk-top simulation is a desirable facility. The development of the SYCOS pilot model has brought this capability closer by simulating piloted flight along prescribed trajectories such as the Mission Task Elements of ADS-33. This development has overcome some of the limitations of the precise control of inverse simulation, by adopting a structure which includes a corrective component that adjusts the control strategy to counteract departures from the desired flight path. The development and implementation of SYCOS for a range of rotorcraft types and applications is shown to be well defined and straightforward. The capability and reliability of SYCOS is demonstrated through a number of recent applications in performance, control strategy and pilot workload studies. Some of the applications benefit from enhancements to the basic structure and these are described in context. The accumulation of experience with the SYCOS pilot indicates that it is a significant advance as a predictor of human control activity during helicopter manoeuvring flight.

Air-breathing propulsion has the potential to decrease the cost per kilogram for access-to-space, while increasing the flexibility of available low earth orbits. However, to meet the performance requirements, fuel-air mixing inside of scramjet engines and thermal management still need to be improved.

An option to address these issues is to use intrinsically generated vortices from scramjet inlets to enhance fuel-air mixing further downstream, leading to shorter, less internal drag generating, and thus more efficient engines. Previous works have studied this vortex-injection interaction numerically, but validation was impractical due to lack of published experimental data. This paper extends upon these previous works by providing experimental data for a canonical geometry, obtained in the T4 Stalker Tube at Mach 8 flight conditions, and assesses the accuracy of numerical methodologies such as RANS CFD to predict the vortex-injection interaction.

Focus is placed on understanding the ability of the numerical methodology to replicate the most important aspects of the vortex-injection interaction. Results show overall good agreement between the numerical and experimental results, as all major features are captured. However, limitations are encountered, especially due to a localised region of over predicted heat flux.

The scope of this paper is necessarily restricted. A large aeroplane, within the new definition, has not yet flown in this country. This event, however, is not very far off and the preparatory work that makes it possible has brought to light many novel problems. In some cases these could be predicted with normal anticipation, whereas others have only emerged as analysis progressed. These latter are frequently good examples of the dangers of too facile extrapolation.

Some of the reasons for having large aeroplanes are examined and subsequently, the chief technical problems arising are described. These descriptions avoid mathematics, as in many cases this approach is extremely long and involved and merits individual publication.

The advantages of using heavy gases in wind tunnels—reduced power consumption and scale size — have been appreciated for some time. To be sure of correct scaling of the results from such a tunnel, the working fluid should have a specific-heat-ratio γ equal to that of air (γ = 1·4); such a fluid can be obtained as a mixture of a monatomic gas with a polyatomic one. Here, general principles for choosing such a mixture are discussed, and estimates are given for the savings in size and scale which may be expected (compared to a conventional tunnel), following earlier work of Chapman.