A future advanced supersonic transport aircraft (AST) has fundamental characteristics and problems inherent to supersonic cruise aircraft with corresponding unique control and handling characteristics.

In order to optimise the aerodynamic performance across the full flight envelope a fully integrated flight and propulsion control system will be required. However, this will need to be designed from the outset within clearly defined flight control and performance guidelines.

Relevant existing and AST specific handling qualities criteria will need to be developed if a successful commercial transport aircraft is to be produced.

This paper begins by presenting an overview of existing supersonic transport (SST) aircraft operations and current second generation SST research activities and design considerations. This is followed by an analysis of the principal aerodynamic, dynamic and control characteristics of SST and AST aircraft and their effect on the aircraft’s handling qualities. Finally, some possible solutions to the control and handling issues are investigated, assessed and presented.

The requirement for an aircraft to operate in the thin atmosphere at high altitudes for long periods provides a particular challenge to all areas of aeronautical engineering. This is reflected in a range of difficulties encountered when attempting to design aircraft for this type of operation.

This paper first considers the reasons for adopting an unmanned solution for high altitude long endurance (Hale) aircraft. It then indicates how the demands of Hale operations lead to problems in applying the design approach taken for more common aircraft types. Some of the work performed at the College of Aeronautics (CoA), in attempting to address the problem areas for the design process and produce initial designs for a range of Hale unmanned aircraft (UMA) types, is then reviewed. The lack of data/methods to allow the prediction of Hale UMA structure mass, engine performance at high altitudes and aerodynamic parameters for low Reynolds number operation and high aspect ratio configurations are identified as particular problems. However, initial design, based on standard approaches, has been shown to be possible, provided caution is exercised.

A series of experiments has been performed in an open-jet wind tunnel on a generic jet-lift STOVL aircraft in transition out of ground effect. In order to obtain information about the forces acting on the aircraft, static pressure measurements were made on the wing and intake lips. The model tested was equipped with a single vectored lift-jet and ‘powered’ intakes. Tests were conducted at a variety of nozzle pressure ratios and effective velocity ratios.

The experiments conclude that a mutual interference exists between the jet and intake flows which generates non-linearly-additive loads on the airframe. This questions the validity of testing jets and intakes separately on a STOVL aircraft of this type.

This paper describes the development of a finite difference method that solves the boundary-layer equations for three-dimensional compressible turbulent flows. The most prominent achievements are the employment of a Newton technique for the simultaneous solution of all governing equations, an option to choose an algebraic or a k-ε eddy-viscosity turbulence model, and the flexible use of curvilinear coordinates. The method is validated by comparisons with a number of experimental and theoretical data sets of three-dimensional, compressible and incompressible, steady and unsteady boundary layers. In parallel, the performance of a three-dimensional compressible industrial integral boundary-layer technique is evaluated by comparisons with experimental test cases and with the results of the field method.

This paper presents a critical study related to the evaluation and breakdown of total wing drag based on solutions of the Euler equations for subsonic and transonic three-dimensional flows.

This study clearly identifies the false entropy production present in all discretised Euler solutions as the main source of the discrepancies between the drag predictions produced by body-surface pressure integrations and far-field methods. A good understanding of the entropy production mechanisms present in discretised threedimensional Euler solutions has lead to an original procedure for the total drag breakdown and a new method for the evaluation of the induced drag. This new technique is based on body-surface pressure integrations and Oswatitsch’s expression integrated over suitable integration surfaces. In contrast with the various methods for the drag breakdown and the evaluation of the induced drag available in the literature, the proposed technique uses an exact formulation and is simple to implement. Using detailed drag calculations on an elliptic wing (the Xt = 1·0 wing) and the ONERA M6 wing, it has been shown that this new technique is not strongly sensitive to grid refinement and to the level of false entropy production in the calculation domain.

A methodology has been developed to integrate the vulnerability discipline into the conceptual/preliminary design process of combat aircraft. An interactive and programmable solid modelling Computer Aided Design (CAD) system is used to generate a CAD solid model of the aircraft’s critical components. The aircraft’s components’ sizes and shapes are pre-defined by a conceptual/preliminary design synthesis computer model. A systematic Child-Parent assembly process is used to model the aircraft vulnerability, by defining the criticality degree of each component in the aircraft assembly. Solid Modelling CAD techniques have been modified to develop techniques to perform the two main standard vulnerability assessments, namely the shotline and vulnerable area methods.