Time-critical targets will generally be observed or ‘sensed’ by personnel inadequately equipped to shoot at them. Since time may be a critical parameter, the passage of information from the ‘sensor’ to the ‘shooter’ must be rapid and accurate. QinetiQ has developed and integrated airborne and ground equipment to facilitate the passage of targeting data digitally over standard air and ground radios. The UK and Holland have selected an integrated rugged PC, internal modem card and purpose-designed software to equip Forward Air Controllers (FACs) to enable digital forward air control. This gives direct interoperability with UK and NATO assets equipped with Improved Data Modem (IDM) technology.

A large, and growing, number of air, land and sea assets employ Link-16. This entails entirely different frequency, data rate and, generally, protocol, from the IDM. The UK MoD’s recently-ended applied research EXTENDOR programme was a three-year operational concept demonstrator for the purpose of translating in near real-time between selected key Link-16 and IDM-based messages. The intention was to demonstrate the viability and utility of translation between disparate data links. This staged programme centred around a translation engine designed to be flown in a Predator UAV. The programme was entirely successful, demonstrating the capability to translate both own position and nine-line target data. Thus the position of a non-Link-16-equipped asset could be seen in real time in the Link-16 recognised air picture (RAP). Also, a Link-16 asset was shown to be able to task an IDM-equipped asset with a nine-line brief via the translation engine. The high equipment readiness level offers considerable potential for near-to-medium term operational exploitation.

This paper considers the effects of both wind-tunnel walls and a downstream support structure, on the aerodynamics of a 70° delta wing. A RANS model of the flow was used with the wind-tunnel walls and supports being modelled with inviscid wall boundary conditions. A consistent discretisation of the domain was employed such that grid dependence effects were consistent in all solutions, thus any differences occurring were due to varying boundary conditions (wall and support locations). Comparing solutions from wind-tunnel simulations and simulations with farfield conditions, it has been shown that the presence of tunnel walls moves the vortex breakdown location upstream. It has also been seen that vortex strength, helix angle, and mean incidence also increase, leading to a more upstream breakdown location in wind-tunnels. The secondary separation line was also observed to move outboards. It was observed that for high Reynolds numbers, with a support downstream of the wing, vortex breakdown can be delayed due to blockage effects providing the vortices do not impinge on the support This was observed to be the case for smaller supports also.

While expansion deflection (ED) nozzles have traditionally been considered primarily for use as altitude compensating devices to improve the performance of single stage to orbit vehicles, they also offer the potential for enhancing high altitude propulsion systems. If intended to only operate in near vacuum conditions, the complexity of analysis and inherent risks involved in the ED concept are greatly reduced. An integrated approach to the design and performance analysis of such nozzles is presented, comprising a mixture of computational fluid dynamics, the method of characteristics, and a semi-empirical model to allow full analysis of the closed wake flow-field of an ED nozzle. While it is demonstrated that the influence of the parameters used to define the throat region is critical to the successful application of the ED nozzle, it is also shown that with careful design the weight savings possible are significant. The analysis method itself is flexible and rapid, and lends itself well to incremental improvements in accuracy as the flow under consideration becomes better understood.

The problem of induced drag reduction during formation flight is revisited by means of a simple aerodynamic model based on lifting line theory. The optimum configuration for minimum induced drag is analysed both in and out of the ground effect and the influence of the main geometrical and aerodynamic parameters is considered. The results are discussed and compared with existing numerical and experimental data.

An analysis is presented both of flight test and simulation data obtained from a gyroplane aircraft. This class of rotary-wing vehicle has found limited application in areas other than recreational flying, however the accident rate has been such that it has prompted the study of the configuration’s stability and control characteristics. It is concluded that the flight dynamic response of the gyroplane examined is dominated by a fast, non-stable mode, affecting all states and thus increasing pilot workload. Simulation results indicate that the position of the centre of gravity significantly influences the stability of this mode.