The pattern of flow at low Reynolds Numbers about an aerofoil in a cascade has been illustrated by the hydrogen-bubble flow-visualisation technique. The method has also been adapted tor the accurate experimental determination of the position of boundary-layer separation. Results of the investigation are presented graphically together with photographs showing the general behaviour of the flow in the wake.

Recent work on the Head-Up Display (HUD) has shown properties of continuous transition, easy learning and accurate use, when certain design principles are followed. Use of HUD in manual landing has suggested application as a monitor for automatic landing and another use is for the directed take-off.

Developments in display techniques have led to a proposal for an electronic flight instrument display (EFID), suitable for head-down, as well as head-up presentation. Economy in presentation area may result from compressing a number of displays into a single format, and from using the same area for a number of displays presented in sequence.

Similar flexible techniques applied to the topographical map display suggest a general-purpose plan position display, complementing the “front elevation” display of flight instruments. These ideas are combined in a proposal for an advanced cockpit layout.

The CHAIRMAN, in introducing the Author, said that Mr VENNING had spent from 1941 to 1946 in the Royal Signals on mobile communications and from 1946 to 1949 at the City and Guilds Engineering College From 1949 to 1952 he had been in the Royal Naval Scientific Service, working on underwater acoustics From 1952 to 1955 Mr Venning had been at the College of Technology, University of Manchester, as a Lecturer in Electrical Engineering In 1955 he joined the University of Southampton in the Department of Electronics where, in addition to lecturing in electronics he was undertaking a research contract for the Ministry of Supply basically on the subject of his present paper

The Chairman, in opening the meeting, said that it was a pleasure to welcome at that meeting of the Association a distinguished engineer from France, Monsieur Rene Dorand, who was well known internationally as a pioneer of the helicopter M Dorand’s name became associated with that of Louis Breguet in 1931 when they built in collaboration a helicopter with co-axial rotors That machine had achieved considerable success both in hovering and in forward flight It established international records for a flight duration of more than one hour and a forward speed of more than 100 k p h, and it also demonstrated an autorotative descent from 100 meters

M Dorand became a graduate engineer in 1921, and in the same year took a diploma in electrical engineering He then joined the Louis Breguet Aircraft Company as a graduate engineer and became Technical Director of the Breguet-Dorand Helicopter development group

The forces due to normal pressure have been measured in the region of the junction between a rear-loaded wing swept forward at 28°, and a flat plate on which a turbulent boundary layer had developed. The Reynolds number was 1·03 × 106, based on the streamwise wing-chord of 500 mm. At low incidences, 0° < α ≤ 6°, the local pressure drag coefficients were found to be negativeaway from the junction, and the interaction with the junction was found to be favourable;that is the pressure drag coefficient became more negative as the junction was approached. At α = −3° the pressure drag coefficient changed from a positive value away from the junction to a negative value close to the plate. These results contrast with those for a swept-back wing-plate interaction, which has been reported as being unfavourable so far as the pressure drag was concerned. At 6° incidence, the interaction remained favourable but there was evidence of root stall beginning. At an incidence of 9°, root stall was much more marked and the positive pressure drag coefficient increased as the junction was approached.

In the analysis of aircraft flight dynamics problems at high incidence, non-linear aerodynamic effects are of considerable importance. The aerodynamic phenomena are generally extremely complicated and the non-linearities may be difficult to predict quantitatively. In this note we confine our attention to longitudinal symmetric motion at constant speed and height. Our aim is (i) to enable the pilot to know when he is in a potentially dangerous manoeuvre (which could lead, for example, to a super-stall) and (ii) to determine simple control laws for an autopilot which would prevent such a super-stall occurring.

This paper assesses the application of a new method for system stability analysis, the weight functions method, to the longitudinal and lateral motions of a High Incidence Research Aircraft Model. The method consists of finding the number of weight functions that is equal to the number of differential equations required for system modelling. The aircraft’s stability is determined from the sign of the total weight function; which should be negative for a stable model. The Aero-Data Model In Research Environment (ADMIRE) simulation, developed by the Swedish Defence Research Agency, was used for the aerodynamic aircraft modelling, with the following configurations: Mach number = 0·25, altitude = 500m, angle-of-attack [–10 to 30]°, elevon deflection angle [–30 to 30]°, canard deflection [0° and 25°] and rudder deflection angles [–30° and 30°]. These flight configurations were selected because they are among the flight conditions for Cat. II Pilot Induced Oscillation (PIO) criteria validation, performed on the FOI aircraft model presented in the PIO Handbook by the Group for Aeronautical Research and Technology in Europe, Flight Mechanics/Action Group 12. This aircraft model has a known instability for longitudinal and lateral motions and so a control law was introduced to stabilise its flight.

The earliest known boats were propelled by oars. Sails were soon discovered, probably in Egypt, where a light, but steady, north wind blows up the Nile. The Egyptians found that by stretching a large mat across the ship they could proceed up the river. However, sails remained an auxiliary source of power until about 300 A.D. because they could be used only with a following wind. Fig. 1 shows an Egyptian ship of about 1600 B.C.

The next improvement came in China, where the square sail was turned fore and aft, enabling the boat to be sailed at an angle to the wind. Unfortunately the Chinese made no further improvements, and the junk, Fig. 2, has remained basically unchanged for about two thousand years.

The 820th Lecture to be read before the Royal Aeronautical Society, “Progress Towards Electrical Serviceability,” was given by R. H. Woodall, M.I.E.E., A.F.R.Ae.S., and V. A. Higgs, B.Sc., A.M.I.E.E., A.F.R.Ae.S., on 1st March 1951 at the Institution of Civil Engineers, Great George Street, S.W.I. Major G. P. Bulman, C.B.E., F.R.Ae.S., President of the Society, presided at the meeting and introduced the lecturers. Mr. Woodall is a Director and Chief Engineer of Rotax Ltd., and Mr. Higgs is Head of Technical Sales and Aeroplane and Automobile Sales of the British Thomson-Houston Co. Ltd.

It is evident from remarks made in previous papers or in discussion on those papers, that the Aircraft Industry is not entirely satisfied with the electrical accessories available for use in aircraft.

There may be some grounds for this dissatisfaction, but it is hoped to make it clear that the electrical equipment suppliers are very much alive to their responsibilities and that development on an ever-increasing scale is taking place in order to give the aircraft constructors the most reliable equipment possible.

The transient motion of a shock wave is investigated during its passage through ducts containing various area convergences. The method of characteristics has been used to follow the unsteady motion of the shock wave in an inviscid, non-conducting gas. The strength of the shock is taken to be large enough so that initially both sets of characteristics face downstream. The results are found to be in good agreement with unsteady and quasi-steady theories. A comparison is made between the characteristics results and experimental results obtained in a 1 ft (0·305 m) diameter shock tube. This shock tube incorporates a 3·75:1 linear area change in the low pressure section length. Good agreement is found between experiment and theory. A comparison is also made with other experimental work.

The pace at which new technologies are assimilated into society is driven by trends in the regulatory, budgetary, and societal environments in addition to the pace of technology development itself. This study merges trends in these areas to develop an integrated forecast of the levels to which unmanned aviation can be expected to emerge in the military, air cargo, business, general aviation, and airline aviation segments over the coming 40 years. One out of every 80 aircraft on an instrument flight rules (IFR) flight plan over the US are anticipated in this forecast to be unmanned by 2025 and two out of nine (18 of every 80) by 2050. Portions of this study were originally researched in 2005 in support of the Federal Aviation Administration’s (FAA’s) Joint Planning and Development Office (JPDO) for planning the Next Generation (NextGen) air traffic system and later presented at the 23rd Bristol UAV Systems Conference.

Because of the lack of reliable data on heat transfer to long bodies, measurements have been made to cone-cylinder-flares at a Mach number of 5·2. Axial heat transfer distributions were closely predicted by a modified reference enthalpy method for both laminar and turbulent flows at zero incidence and the heat transfer to the flare windward generator at incidence agreed with laminar theory.

This paper considers two-dimensional flow past flexible membranes whose supports are aligned at right angles to the flow. Unlike a previous study of bluff impervious membranes, the present membranes are slightly porous having a porosity similar to that of parachutes. The drag and base pressure have been measured for various lengths and for a variety of fabrics. The results have been correlated by two theories which are extensions of those already published. When the porosity is not too small the results are shown to depend only on the total volume flow through the membrane. The tendency for the membrane to oscillate in harmony with regular vortex shedding is reduced by the porosity and increased by the length of the membrane. Above a certain porosity oscillation is inhibited for all membrane lengths.

Whereas a body of theoretical research is available on the conditions of supersonic flow through Laval nozzles and around aerofoils, such is lacking for turbo-machinery in general, with the exception of some researches by Stodola, confined to axial steam turbines. The present paper investigates some important questions relating to the flow at supersonic velocity through centrifugal machines of the general type.

According to the Plowden report, the American worker has weekly earnings of 2 to 2 times those of the British worker. The report also stated that, for the same production run (of 100 aircraft), the average cost in the USA would be between 105 and 115 per cent of the British cost for the same aircraft. This means that the number of man-hours expended in Britain is of the order of 2 to 2 times the number of man-hours taken in the USA for the same job. Or, it means that, if we could make an aircraft in Britain for the same man-hours as in the USA, it could sell at only 40 to 50 per cent of the American equivalent. But bear in mind that the man-hours I refer to are for all employees, not just those usually charged direct.