Heat transfer and pressure measurements were made on a model of the United States Space Shuttle Orbiter in the University of Queensland's T4 shock tunnel at three angles of attack, with stagnation enthalpies which varied by a factor of 11, from 2·1 MJ/kg to 23 MJ/kg and normal shock Reynolds numbers which varied by a factor of 38, from 2·1 x l04 to 8·l x 105. Leeward pressure results were obtained for comparison with flight data and equilibrium calculations, but the majority of the experiments were conducted to investigate the heat transfer distributions around the shuttle model. Both the windward and leeward heat transfer results exhibit the onset of transition to turbulent flow. The leeward results are compared with flight data as well as with conventional wind tunnel data, and are used to establish trends associated with variation in the major flow and geometry parameters. It was found that although high enthalpy effects could be important, Reynolds number effects played a dominant role in determining the flow.

The fatal accident rate in the world commercial fleet of large jet transports has been on a near plateau for more than 15 years since the absorption of the major advances made with the last generation of technology and operational systems.

Notwithstanding continuing technical advances, the increasing size of the world fleet demands more significant improvements if the actual number of accidents is to be reduced.

This paper promotes the view that a further overall increase in the safety of air transport from the high levels currently achieved is unlikely to come about by normal evolution. It suggests that what will be required in future is planned improvements, quantified by statistical safety assessment methods. Such assessment should encompass the totality of an integrated Air Transport System, as distinct from the current practice of assessing the Aircraft Airworthiness, Air Traffic Management, Flight Operations Management and Air Navigation systems in isolation. The setting of new targets for overall safety should derive from an integrated systems approach.

A relevant history of systems statistical safety assessment is reviewed, and certain aspects of cockpit automation and systems which may contribute to the future advancement of overall safety are considered.

A comparison between computed and experimental pressure distributions on straight and forward-swept wings placed in interference with a fore canard surface at M = 0·3 and Re ≈ 2·8x106 is presented. It is shown that a numerical code, based on a non-linear vortex lattice method and expressly developed for the analysis of interfering lifting surfaces, is capable, in spite of its simplicity, of very accurate predictions in all configurations which do not correspond to sufficiently high angles of attack and to a close interference between the fore wake and the wing surface. Furthermore, even in the latter cases the predictions are acceptable, and the code is shown to be extremely robust as regards the variation of all its free parameters.

An economical numerical method has been developed to calculate unsteady aerodynamic characteristics of aircraft configurations, undergoing small amplitude simple harmonic motion in various laterally symmetric modes of oscillation, in inviscid incompressible flow, by taking advantage of the computational efficiency of internal distribution of singularities. The only approximation introduced in the method is the linearisation of the problem with respect to the amplitude of oscillation. A number of comparisons have been made to demonstrate the effects of different aircraft components on wing or tail pressure, and lift distributions.