Forty years ago, in September 1958, the International Council of the Aeronautical Sciences held its first Congress in Madrid. Since then, there has been an ICAS Congress every two years and in September 1998 the 21 st Congress will take place in Melbourne. This will be the first ICAS Congress to be held in the Southern Hemisphere -an important step for ICAS and a reflection of the ever more global nature of aeronautics.

The vision of the Founding Fathers was that the ICAS Congress should provide aeronautical scientists and engineers from all around the world with a forum in which they could meet to learn of new results, exchange ideas and experiences and develop professional friendships, free from political and ideological constraints. It has served that vision well and over the years has increasingly established itself as the foremost international forum for aeronautical science and engineering. Today, with the ideological barriers largely removed and the international dimension of overriding importance in aeronautics, the value of the ICAS Congress has never been greater.

The call for papers for the 21st Congress attracted more than 500 submissions from 32 countries. From these the ICAS Programme Committee, chaired by Jean-Pierre Marec of France, had the daunting task of selecting about 270 papers for presentation. The calibre of the authors and the quality of their submissions was well up to the high standards set by previous ICAS Congresses and, as is evident from the programme set out in the following pages, ICAS 98 promises to be a highly stimulating and rewarding event.

The city of Melbourne will provide a most attractive venue for the Congress and, on behalf of ICAS, I must thank the Australian Division of the Royal Aeronautical Society for undertaking the substantial organisational task that is entailed in hosting this event. I am personally delighted that the Division proposed Australia for ICAS 98 and I have no doubt that, for everyone who participates in the Congress, it will be a meeting to remember.

John Green, President of ICAS