It is customary to begin lectures of this kind with reference to the person after whom the lecture is named. I do so with particular relish on this occasion.

This is because I spent most of my working life at The City University, formerly The Northampton Polytechnic, with which Sir Frederick Handley Page was closely associated throughout his working life.

The results of a little archival work reveal that in June 1909 a class in aeronautics was arranged for the following session. As it turned out, the momentous event of 1910 was the appointment of a Mr Frederick Handley Page to be lecturer in aeronautics to attend for two evenings per week at £75 for the session.

Not surprisingly the subject was a great success at the Northampton, and 81 years later at The City University, it still is.

Any review of the development of maritime satellite communications is essentially the history of Inmarsat and its predecessor system, Marisat. With perhaps two qualifications, one might extend the definition to mobile satellite communications generally. In the land mobile satellite communications domain two companies, Geostar and Qualcomm, have also made their mark. Geostar was recently declared bankrupt but Qualcomm continues to go from strength to strength.

We are frequently asked ‘what is Inmarsat?'. The term Inmarsat is generally used, and used herein, to mean the permanent staff (the Directorate), Land Earth Station (LES) operators, manufacturers and value-added service providers who offer mobile satellite communications products or services via the satellites and other infrastructure which makes up the Inmarsat system. It is, essentially, a partnership but within it there is also internal competition. LES operators compete in the provision of telecommunications services (quality is consistently high, but they each decide what services to offer and at what tariffs). Manufacturers compete to secure market dominance and profitabilty for their products. Not all will be equally successful. More than anything, Inmarsat is a global partnership dedicated to meeting mankind's need to communicate while on the move. It aims to do so cost-effectively and using satellites.

A systematic parametric investigation of the flutter behaviour of a binary wing-with-engine nacelle system in inviscid incompressible flow is performed. The equations of motion in coupled bending and torsion are initially set up and the aerodynamic model for the calculation of the motion-induced unsteady airloads is described. The aeroelastic stability equations are then derived in non-dimensional form and the procedure used for the numerical solution of these equations is outlined. For a typical large commercial aircraft configuration, numerical results are presented for a variety of systematic parameter variations with special emphasis on the effects of the location of the elastic axis and the motion-induced unsteady airloads on the engine nacelle.

Analysing the action of atmospheric turbulence on aircraft for the determination of limit and fatigue loads is an essential stage in the structural design process. These calculations are governed by regulations, the evolution of which is of great importance to the aeronautical industry. The aim of this paper is to present the various calculation methods used for the preliminary dimensioning, substantiation and certification of aircraft, and to assess, on the basis of aircraft response studies and comparisons of loads calculated, the repercussions of the progress which has been made in recent years. Moreover, the regulatory requirements currently in force internationally, though often disparate and unbalanced, are now aimed at standardisation as a result of the impetus of both the airworthiness authorities and the aeronautical industry. Against this background, we propose a new calculation method developed on the basis of results obtained at Aerospatiale.

Aircraft response to atmospheric turbulence is a basic problem in aeronautical design. Several uncertainties still exist about the most adequate mathematical model for it. A recent investigation conducted by AGARD revealed that different users follow very different criteria.

The reasons for this diversity in analysis methods is only partially due to the randomness of the phenomenon. Three elements are the ingredients: structure, aerodynamics and turbulence distribution. No special problems arise from the first element, since structural dynamics and programs relevant to it are well established. For the aerodynamic model, the only choice is between quasi-steady and unsteady formulation, the latter being by far heavier than the former. For turbulence distribution, as is well known(2-4), two different approaches are used, time history and power spectral density (PSD); both are used in the regulations of national certifying agencies. For the latter the turbulence power spectrum must be given, and the aircraft response is evaluated through the classical theory of random vibrations.