This paper examines the changing role aerodynamic technology plays in the design and development of modern combat aircraft. It reviews several aspects of aerodynamics which contribute to aircraft performance and handling characteristics. It considers the importance of a range of technologies, the contribution each makes to the final integrated solution and comments on the compromises necessary through the design cycle to optimise the overall weapon system, sometimes to the cost of one of the component technologies. The technologies discussed are in no way exhaustive but attempt to encapsulate the breadth of the subject, to illustrate its diversity and to point the way for the future development if aerodynamic technology is to continue to make an important contribution to the design of combat aircraft.

Each of the component technologies are discussed in terms of the contribution it makes, the tools and techniques used to predict, analyse and interpret the technology contribution, and the requirements for the direction of the development of the technology for the future.

Before considering the technologies themselves it is important to understand the environment in which they will be used, which increasingly conditions the manner in which they are employed and suggests the direction for their development.

This paper begins, therefore, by briefly reviewing the changes to the environment in which the fighter pilot operates and the manner by which his requirements, and therefore the specification of the aircraft, are defined before going on to look at the overall contribution each technology makes in the design process.

The space industry of the late 20th century is not simply a subset of the aerospace industry: it is a producer, an employer and a wealth creator in its own right. This paper reviews the current state of the art in space technology by analysing the development of an industry which produces both a wide variety of spacecraft and the launch vehicles which deliver them to orbit. In doing so, it considers the application of spacecraft for communications, navigation. Earth observation and science, as well as their application to manned space flight.

By considering some of the problems that need to be solved in order to develop the field beyond its current state, the paper then looks forward to the developments in these areas expected in the 21st century. The interrelated development of international co-operation — as opposed to political competition — and the rise of space commercialisation is considered throughout.

The paper reviews the developments in avionics over the last seventy years, focusing on the impact of computer technology during the last ten years. The development of aircraft navigation systems is described, including present day satellite navigation and terrain reference navigation. The techniques used in aircraft displays are outlined including CRTs and LCDs and covering head up displays, helmet mounted displays and synthetic displays. The systems architecture which forms the basis of modem avionics is described, covering the major aircraft databuses in use including recent developments in integrated modular avionics. Developments in real-time software, which has become a major cost in many programmes, are covered, leading to the techniques used to ensure aircraft reliability, particularly fault tolerant architectures and also safety systems for health monitoring and recent research in ‘pilot associates'. The paper also summarises developments in flight control systems for both civil and military aircraft. The paper concludes with a brief review of future developments in avionics, speculating on the role of pilot in future aircraft.

The rotorcraft has evolved considerably since the introduction of the first helicopters into civil and military service in the early post-war years. The latest generation of rotorcraft now entering production make use of sophisticated technologies and set new standards for performance, productivity and safety. The paper discusses the current state of rotorcraft technology and outlines potential improvements for the future.

As a prelude to the discussion of technology improvements, future market conditions and drivers are examined. Cost is highlighted as a major preoccupation for civil and military operators and cost-effectiveness and operational flexibility are noted as the key market requirements for the future.

A range of platform and system issues are reviewed and potential improvements discussed. Areas covered include

• • rotor systems

• • powerplant

• • transmission

• • fuselage structures

• • vibration reduction

• • flight controls

• • human machine interface

• • mission systems.

The potential for new rotorcraft configurations is considered with particular attention given to the evolutionary step of thrust and lift compounding, which offers a wider flight envelope for rotorcraft without the high cost of radical configuration change.

Finally, the need for an integrated approach to the rotorcraft design and development process is emphasised. The highly capable tools and techniques that are now becoming available are considered vital to future process improvements. It is foreseen that increased resources will be needed during the early stages of product development in order to produce first time designs that meet market requirements. The importance of technology demonstration as a means of providing technology maturity is discussed. It is concluded that demonstration programmes will need to be closely linked to market requirements in the future with costs shared between all sections of the rotorcraft community.

A discussion is presented of innovative change in aerodynamics, in which the transformation of practical transonic aerodynamics by computational fluid dynamics is taken as a case study for the lessons to be learnt. The study focuses on the historic breakthroughs of Emmons and Murman and Cole in the calculation of transonic flows, and on the exploitation of these at the Royal Aircraft Establishment to provide industry with a new, and highly successful, tool for practical transonic wing design. It reaffirms the view that a first prerequisite for innovation is the active presence of individuals with clear vision and a spirit of adventure. Further, innovative work will flourish only if the climate is favourable, no matter how exceptional the individuals may be. The discussion concludes with remarks on opportunities for innovation in the treatment of Shockwaves, turbulent shear layers and complex practical configurations.

Today the aerospace industry is ranked in the top three industrial sectors in the UK. With air traffic expected to more than double by 2015, there are tremendous wealth creation opportunities for those who satisfy their customer's needs. Innovation — the successful exploitation of new ideas — is a key ingredient in achieving this. It is an engine of growth because it delights the customer — and that delight is the basis for long-lasting customer loyalty. Henry Royce recognised the importance of exceeding the customer's expectations and laid the foundations for Rolls-Royce's long tradition of innovation. With historical illustrations, from the Silver Ghost motor car to today's flagship — the Trent aero engine — this paper highlights the key elements which are necessary to promote innovation and have led to many Rolls-Royce “firsts”. A review of today's state-of-the-art aero engines details current innovations, and their associated customer benefits, while a view of future markets reveals an insight into future aero engine developments and technical challenges. The solution to some of these challenges will require the application of advanced technologies. In anticipation of the customer's requirements, the development of these advanced technologies is discussed together with their potential customer benefits.

This paper reviews the status of aerospace materials currently under development or moving to application and assesses the difficulties inherent in their transition from research to commercial use. The author then speculates upon future trends in aerospace structures and on the consequences for advanced materials.

ACT embodying FBW and digital computing is now implemented routinely in almost all classes of aircraft, and is often essential in achieving performance requirements. However, careful design, thorough understanding, and attention to detail are necessary if the benefits of ACT are to be realised and attention must be focused appropriately among the issues to be resolved to ensure that development proceeds efficiently and overall costs are minimised. This paper introduces structural coupling as one of the important “details” of FCS design, and shows how the “state-of-the-art” has developed at BAe Warton in order to help achieve the performance specification for a modern weapons system, while maintaining a balanced and efficient FCS design effort.

This article attempts to look forward in the field of aircraft structures, at what is likely to happen, and what current R&D is necessary to achieve this. It becomes clear that structural performance is always improving but that the main drivers are likely to be cost, both capital cost and in-service costs. The capital cost is likely to improve by reducing the design and development time as well as low-cost manufacturing. The use of all components of the synthetic environment are here playing an increasing role. The in-service costs will be reduced by more robust structures and better NDE to automate inspections and lengthen their intervals.

The high noise levels of early turbojet aircraft forced attention to be given to the mechanics of the noise generation process and ways were urgently sought for silencing their high speed propulsive flows. The subject of aeroacoustics was born with this problem, the subject being the variety of ways in which sound and flow interact, with the early emphasis being on sound generated aerodynamically. Sound was thought to be a by-product of the flow arid believed to have a negligible back-reaction on it.

The search for noise suppression has been extremely successful, so much so, that engine noise is no longer a problem likely to constrain future aircraft operations. Silencing technology has made enormous strides by avoiding as much as possible the very high speed jet flows that were a feature of early engines. But that avenue is not available to supersonic aircraft, which still wait for ways of making their operation acceptably quiet to be identified.

Aeroacoustics has brought into being a much deeper insight into the interactions of sound and flow, and some of the early presumptions about the mechanisms of noise creation have had to be rethought. Some of the advances have come from entirely new directions, for example, from anti-sound, a silencing idea based on the destructive cancellation of interfering waves, which has advanced to a state that provides a useful new technology. Some new understanding follows the discovery that flow-acoustic interactions are not always the one-way process previously assumed. Sound can affect flow, especially so when the flow is unstable. It is of course the very unstable flows that make most noise so, taken together, these developments indicate that control might one day be exercised by actively managing the unsteady flows, making them more useful and desirable than before. Indeed examples are now known where control has made possible the avoidance of a powerful performance-limiting instability that previously made that flow regime a prohibited operational zone, a development of aeroacoustics that is probably far more significant than its noise suppression role. That line of thought is expanded in this paper, which concludes with the speculation that active control might now be offering an avenue for approaching die high speed jet noise problem from a completely new direction. Of course it is far too early to know whether that approach can provide a way for removing the take-off noise constraint currently threatening the viability of supersonic transports, but it might; that makes it very important indeed, for it is hard to see any alternative.

Over the past 20 years, the issue of manufacturing large composite structures has been intensively addressed. Military aircraft have seen ambitious developments which have been transferred successfully into production. Large commercial aircraft have seen less ambitious developments productionised at relatively high cost when compared to aluminium. This paper reviews developments in these sectors. Outstanding issues for affordable manufacture of large composite structures are discussed with reference to current design and manufacturing research programmes.