The aim of this work is to investigate how the wake vortex hazard generated by an aircraft can be reduced by modifying the wing lift distribution. The wake associated with a given lift distribution is simulated with a two-dimensional, in viscid ‘vortex method’. A numerical optimisation technique is used to guide the modifications so that a hazard measure, based on the rolling moment induced on a following aircraft encountering the wake, is minimised. The results show that a significant (~20–25%) reduction in hazard compared with conventional high-lift configurations can be achieved, via lift distributions that have a local minimum between the regions contributing to the flap and tip vortices. The counter-signed vorticity associated with this minimum appears to prevent the tip and flap vortices from merging, resulting in a safer wake. Furthermore, the hazard reduction is robust to variations in other features of the lift distribution and should thus be achievable in practice.

Over the years there have been aircraft accidents and incidents where crews have been found in error. Many times the errors were found with hindsight to have been compounded by poor checklists and inadequate design. Of particular concern to the author is the dilemma of ‘smoke and fire of unknown origin’. This is a serious emergency with little time for complex troubleshooting. It is a human factors classic ‘fight or flee’ scenario. Research among the major UK airlines, assisted by the UK Flight Safety Committee, has revealed that there is an inconsistency in direction as to when to recommend divert and land as of paramount importance. Thus a gap is created and those believed to be responsible identified. The author has experienced several instances and takes the opportunity to describe one of them. Lessons are included on work being done in modifying aircrew training to cater for the removal of the flight engineer. Design recommendations are made and warnings given about the future. Should recommendations in the wake of accidents and incidents be ‘risk managed’ by the regulators? Ultimately, the crews are forced to rely on their checklist handling and limited technical knowledge that sometimes means that the gap is too wide and an incident occurs. The paper is a collaborative effort prepared by the author on behalf of the RAeS Flight Operations Group (FOG) but the author alone is responsible for the version published.

The US Naval Research Laboratory (NRL) is developing technologies that will enable Navy-relevant missions with the smallest practical Micro Air Vehicles (MAVs). The NRL Micro Tactical Expendable (MITE) air vehicle is a result of this research. MITE is a hand-launched, dual-propeller, fixed-wing air vehicle, with a 25cm chord and a wingspan of 25–47cm, depending on payload weight. Vehicle gross weight is 130–350g. Miniature autopilot systems, based on visual imaging techniques, are being developed for MITE. These will be used in conjunction with conventional autopilot sensors to allow the MITE to fly autonomously. This paper provides an overview of the MITE development, including aerodynamic design considerations, electric propulsion, and vision-based autopilot research. Also presented is a rationale for the development of control laws that can direct the behavior of large groups of MAVs or other vehicle agents. Dubbed ‘physicomimetics,’ this process can bring about the self-assembly of complex MAV formations, though individual MAVs have minimal onboard processing power and limited local sensing capabilities.

With the advent of thrust vector control and post stall manoeuvrability affecting the design of modern combat aircraft, there still remains a shortage of performance metric tools available to the conceptual designer. The need for such a tool is highlighted, and a suitable metric is introduced. Using the metric, the effects of thrust vector control and post stall manoeuvrability are investigated quantitatively for a 180° heading change in the horizontal plane, in terms of time to complete the manoeuvre, final Specific Excess Power, energy change over the manoeuvre and turn diameter. The extension of the metric to investigate different manoeuvres and the impact of other new technologies is briefly discussed.

A novel, non-intrusive, high spatial and temporal resolution thermal imaging system, based on the fluorescence properties of a dysprosium doped yttrium-aluminum-garnet (Dy3+:YAG) thermographic phosphor, has been developed. In this system, the phosphor coating on the test surface is excited by a pulsed Nd:YAG laser. The resulting fluorescent emission of the temperature sensitive 456nm transition and that of the temperature independent 496nm transition, are acquired using a pair of image-intensified charged coupled device cameras. The ratio of the acquired emissions is then correlated to temperature. The Dy:YAG phosphor displays temperature sensitivity in the range of 295–l,350K (with possibility up to 1,800K). Temperature measurements obtained from the surface of a disk heated by an impinging jet, demonstrate the feasibility of this technique for general heat transfer studies involving significant unsteadiness and transient phenomena.