The use of rule-based fuzzy logic system for estimating the stability and control derivatives for the longitudinal aircraft motion is proposed. The capabilities of the fuzzy logic system in estimating both the short-period and the phugoid mode of motions are explored. The flight data used in the estimation process were generated using the three nonlinear longitudinal equation of motion for a small remotely piloted vehicle with all the aerodynamic coefficients obtained from the wind-tunnel tests. The preferred method of perturbation of the aircraft elevator for data collection is also highlighted. The stability and control derivatives are estimated as the change in the aerodynamic force or moment due to small variation in one of the motion or control variables about its nominal value when the rest of the variables are held constant at their respective nominal values. The changes in the aerodynamic force and moment are predicted using the fuzzy logic system. The results show that the fuzzy logic system has a good potential as alternative tools for parameter estimation from flight data. The proposed method does not require any guesses of the initial values of the flight parameters.

The compressive stability of anti-symmetric angle-ply laminated plates with particular reference to the degrading influence of membrane-flexural coupling is reported in this paper. A specific configuration of anti-symmetric laminate is dealt with in the paper and this takes the form [θ/-θ]n whereby 2n is the total number of plies in the laminated stack. With regard to compressive buckling the paper gives an indication that anti-symmetric laminates with 8 plies or more will yield performance levels which are almost identical to their symmetric counterparts. The degree of membrane-flexural coupling in the laminated composite plates is varied, essentially, by changing the ply angle and also by altering the number of plies in the laminated stack, for a given composite material system. The coupled compressive buckling solutions are determined using the finite strip method of analysis. In order to provide an adequate level of flexibility in the analysis procedure and to ensure a high level of accuracy of solution, the buckling displacement fields of the strip formulation are those which are described in a multi-term form.

Results are given for anti-symmetric angle-ply laminated plates subjected to uniaxial and biaxial compression and these have been obtained from fully converged finite strip structural models. Validation of the finite strip formulation is indicated in the paper through comparisons with exact solutions where appropriate. The natural half-wavelength of the compressive buckling mode of the composite plates is shown to be significantly influenced by variation in the ply angle. Increasing the number of plies in the laminated system is seen to reduce the degree of coupling and the critical stress levels are noted to tend towards the plate orthotropic solutions. The ply angle corresponding to the optimised, compressive buckling stress for any particular laminate is noted in the paper to be influenced by the support boundary conditions at the plates unloaded edges.

This paper sets out the case to extend the role of flight simulation in general aviation. It outlines the benefits that flight simulation has brought to airline safety but observes that the majority of pilots worldwide receive no simulator-based training or checking. The paper reviews the potential benefits of synthetic training and provides an analysis of accidents in general aviation to show that a significant reduction in fatal accidents is achievable by instituting recurrent pilot checks in a flight simulator, similar to the simulator checks undertaken by airline pilots. The paper summarises the advances in simulator technology which have occurred in recent years and outlines a scheme to fund the introduction of flight training devices in general aviation, based on compulsory recurrent checks for PPL and CPL pilots. The paper surmises that flight simulation offers a practical means to reduce the accident rate in general aviation and concludes by outlining a financial case to fund the introduction of mandatory simulation-based recurrent checks in general aviation.

This paper reviews the requirements of the AHS human-powered helicopter (HPH) competition and discusses the feasibility of such a helicopter. Analysis is carried out with modified forms of the axial momentum theory to take into account the ground effect. Descent in autorotation is also considered. The main conclusions are: human-powered hover out of ground effect is not possible; the power loading decreases with the number of pedaling crew members; hover in ground effect significantly increases the rotor thrust at given power; the HPH operates in the vortex ring state; in principle, either altitude or endurance records can be reached for the AHS contest, but not both, due to insufficient power.

The objective of our paper is to demonstrate the use of spectral/hp element technology in unravelling global flow instability mechanisms. Understanding these mechanisms is central to devising flow control approaches based on theoretically-founded physical principles. Global instability theory is concerned with prediction and control of linear and nonlinear disturbances developing in flows that are inhomogeneous in more than one spatial direction. As such, this theory encompasses the classic analysis of Tollmien which is valid for simple geometries of academic interest (e.g. a flat-plate) and therefore broadens the scope of this well-established but simplified methodology to include realistic problems encountered in aeronautical engineering. Compared with a direct numerical simulation approach, global instability theory can be used to explore efficiently far wider parameters ranges and deliver physical information to be used as handle for effective flow control.