On the afternoon of 14th April 1987, the Society held a half-day symposium on wing-tip flows and devices. Papers were presented by J. J. Spillman of Cranfield Institute of Technology on wing-tip sails, by A. C. Willmer of British Aerospace (in association with R. V. Barrett and J. D. Coleman of Bristol University) on the tip flow of part-span flaps, and by H. P. Horton of Queen Mary College on measurements in the viscous flow regions of streamlined tips. Written versions of two of these talks and a synopsis of the third* have been prepared and are being printed in the Journal following these introductory remarks. The contribution by J. S. Smith of RAE to the discussion session is appearing elsewhere.

Since 1993, research at Loughborough University has included examining the commercial air safety record of Australia in an attempt to rise to the challenge posed by Professor James Reason: “Should we not be studying what makes organisations relatively safe rather than focusing upon their moments of unsafety? Would it not be a good idea to try and find out what makes them good and whether or not these ingredients could be bottled and handed on?”.

The objective is not to prove Australia to be the safest place to fly, nor its airlines the safest in the world. It is simply to examine what sort of defences are in place that may be strengthened or emulated.

This paper studied the use of eye movement data to form criteria for judging whether pilots perceive emergency information such as cockpit warnings. In the experiment, 12 subjects randomly encountered different warning information while flying a simulated helicopter, and their eye movement data were collected synchronously. Firstly, the importance of the eye movement features was calculated by ANOVA (analysis of variance). According to the sorting of the importance and the Euclidean distance of each eye movement feature, the warning information samples with different eye movement features were obtained. Secondly, the residual shrinkage network modules were added to CNN (convolutional neural network) to construct a DRSN (deep residual shrinkage networks) model. Finally, the processed warning information samples were used to train and test the DRSN model. In order to verify the superiority of this method, the DRSN model was compared with three machine learning models, namely SVM (support vector machine), RF (radom forest) and BPNN (backpropagation neural network). Among the four models, the DRSN model performed the best. When all eye movement features were selected, this model detected pilot perception of warning information with an average accuracy of 90.4%, of which the highest detection accuracy reached 96.4%. Experiments showed that the DRSN model had advantages in detecting pilot perception of warning information.

Approximate Solutions obtained by the method of collocation are presented for the lowest critical buckling load of an isosceles triangular plate loaded as shown in Fig. 1. Also, the fundamental frequency is given. The base of the triangle is simply supported and the other equal edges are clamped. The usual assumptions regarding the bending of thin plates are made. The governing differential equation for the plate loaded as shown in Fig. 1 is

1

where D is the plate stiffness, N is axial load per unit length, w is deflection, positive downward, and the quantities a and h are dimensions shown in Fig.1.

The setbacks and frustratons encountered in the desgn and construction of man-powered aircraft are well-known. Many machines have been completed only after the expenditure of several man-years’ effort. Often, groups have reaped little reward in proportion to their labours. The majority of man-powered aircraft have suffered severe damage early in their flight career either from storage accidents, from mismanagement in ground handling, or following loss of control while in flight. The record underlines the vulnerability of these lightweight, flimsy aircraft and emphasises the difficulty in conducting safe operations while simultaneously achieving productive flying.

In his 1916 book, Aircraft in Warfare, the Dawn of the Fourth Arm, F.W. Lanchester wrote:

The recent successful flight trials of the Taranis low-observable unmanned demonstrator aircraft provide the latest evidence of the UK’s continued capacity for the entire design, development, manufacture, and flight testing of world-leading combat aircraft, particularly with regard to Aerodynamics. Taranis is both the culmination of many years’ research and development in the UK and a starting-point for the next generation of UK combat air systems.

In this lecture, Taranis is reviewed, in such detail as current sensitivities will allow, in the wider context of UK combat aircraft aerodynamic capability, exemplified by the leading roles taken by the UK in the Tornado and Typhoon programmes and the important contribution made to the development of the F-35 Lightning II Joint Strike Fighter.

The immediate technical challenges associated with the aerodynamic design and qualification of a low-observable air vehicle are considerable. In this instance they have been compounded by the balanced view taken within the project of trade-offs against many parameters. However, the UK aerodynamics community faces equally stringent challenges in terms of the identification and delivery of the most appropriate future systems; increasingly complex and demanding operational and functional requirements; and, perhaps most of all, maintaining an affordable and cost-effective capability in the face of strict budgetary pressures and austere economic conditions.

Nevertheless, those challenges are accompanied by a wide range of opportunities, namely for national and international partnership; radically innovative engineering solutions and approaches; new thinking; and the engagement of the best minds and ideas in the UK academic community.

Taranis represented a big integration task, requiring a particular set of skills to pull together the total package, resting on a bedrock of mastery of the technical issues. It has been an inspirational experience for those of us who have worked on it. It has demonstrated that the UK is capable of achieving the most demanding current and anticipated military aerodynamic requirements and has signposted the way to an exciting and nationally important future.

Terms used in the description and analysis of the external drag of a body (with or without internal flow) are considered, and definitions suggested for the various components of the drag. Care has been taken to ensure that the proposed terms are consistent with those used in the Panel's report on thrust.

An investigation of the four-bladed Dowty Rotol R212 propeller (NACA 16 sections) has been made at l/5th scale (0·7 metre diameter) in the RAE 1·5 metre acoustic tunnel. Propeller power absorption and thrust have been measured over a range of rotational speeds up to 8000 rev/min at mainstream speeds from 15 m/s to 60 m/s for a range of blade settings. Slipstream wake surveys show outward movement of the position of the peak pressure as propeller loading is increased.

Noise analysis demonstrates the predominance of multiple tones whose number and intensity increase with helical-tip Mach number. An empirical formula shows that the fundamental tone SPL varies with tip speed and power loading in an identical manner to that observed on a modern ARA-D section propeller.

I want this evening to present some reasons for believing- that we can build successful aeroplanes of enormous size, and, what is more important, that they will not be merely monuments to a desire for the gigantic.

In the past, bold computers have defined upper limits to the size of aeroplanes. Their prophecies have varied, and most of them have been belied by practical achievement. Their arguments were usually based on what has been called the “ Cube Law ” or the “ Square-Cube Rule.” This rule, though it has apparently proved misleading, is indeed correct when properly applied, and it forms a convenient point from which to begin an enquiry into the feasibility of the giant aeroplane.

Box beams, built up essentially with flanges and webs are widely used in aircraft construction and much has been written about their calculation. But often assumptions are implicitly made without reason. The first aim of this paper is to point out which assumptions must be chosen and why, and to show what results may be expected from them. The calculations are then developed in the. cases of the quadrangular box beam and the wing with three spars (redundancy of the first degree).

For a multi-vectored propeller aerostat with actuator faults, this study presents a fault-tolerant tracking control strategy, which includes fault modeling, observer, force estimation and tracking controller. Fault modeling considers the four types of faults of vectored propellers, namely, thrust offset, thrust efficiency loss, vectored angle offset and vectored angle stuck. Actuator faults can be determined from the fault observer, which identifies the thrust offset from the acceleration difference of the faulty aerostat with the ideal model. For tracking positions, a traditional PID controller is constructed with virtual control, compensated with the estimated fault force. The control allocation scheme is proposed to redistribute the available actuators in case faults occur. Simulation results of position tracking prove the effectiveness of the proposed strategy.

Before starting this discussion I must apologise to the many people here who have considerably more experience of civil instrument flying in helicopters than I. However, the major part of this talk is merely a history of the certification of the Bölkow BO. 105 for instrument flying. We all realise that flying under IFR is not the all weather flying quoted in the title of today's symposium however for the light helicopter it is a very significant step forward. My personal experience of this programme is very limited, and indeed the Civil Aviation Authority knows more of both the design philosophy behind the IF installation and the actual tests conducted than I. I intend to give a short historical description of the problems encountered and envisaged in getting the certification, followed by the equipment required in the aircraft and the use that an operator could make of a machine of this size when IF equipped.