This corner of England has seen the evolution of some notable aircraft, Canberra, Lightning, Jaguar, Tornado. Mr Yates, in the inaugural lecture of this series last year, gave a brief historical review of the growth of English Electric and of these aircraft, indicating in particular the key part played by Sir Frederick Page in both the build up of the firm and in the design and development of the aircraft. It is most appropriate that we should again honour him here on what I regard as his home ground and in his presence.

But Sir Frederick's contributions to aerospace have been much more than local to Lancashire. He has been at the centre of the gathering together of all the elements of what is now British Aerospace PLC. He is a past President of the Society of British Aerospace Companies and has actively supported the Royal Aeronautical Society, not least as President of this Branch from 1962 to 1967.

It is a privilege and a pleasure to have this opportunity to talk to you about progress in vertical and short take-off and landing (V/STOL) aircraft technology. I must admit at the outset to some trepidation in accepting the invitation of the Society to speak on a subject that was successfully pioneered in the United Kingdom and brought to its current operational state largely because of the enduring faith of the Harrier team. However, I hope that the more modest progress that has been made on a variety of STOL and VTOL concepts will also be of interest to you; at the very least, this talk will identify some of the blind alleys to be avoided and, with a little luck, point out some new directions for future research. I will confine myself largely to the V/STOL technology with which I have been involved over the 1970–1980 period at Ames Research Center.

In the aeronautical field, there has been from time to time an interest in inflatable structures, ranging from their consideration for use in space to the design and manufacture of an inflatable wing for a man-powered aircraft and their use in remotely piloted vehicles . This interest stems from the fact that such structures have relatively low weight; are suitable for reacting light loads and can be packed into a small volume.

One particularly useful structural component is the inflated circular cylinder acting as a cantilever and a number of such cylinders are used in Ref. 3 to form the main load carrying structure of a wing. In Ref. 1 an expression is derived for the collapse load of a single cylinder with the assumption that the root behaves like a plastic hinge, and in Ref. 5, Comer and Levy go on to consider the beam deflections and stresses between incipient wrinkling and final collapse.

The aviation fuel market is one of the few areas in the petroleum industry where an increase in future demand can be predicted with a reasonable degree of certainty. However, this growth in demand is likely to be influenced by two major constraints, price and availability. At present aviation fuel represents only a relatively small portion of the barrel, but any increase in this fraction is limited by the need to meet specification requirements and competition from other products. The changing pattern in product demand is focusing attention on secondary refinery processes to maximise output of distillate fractions and on the use of alternative non-petroleum sources of fuel. In both of these approaches, significant upgrading of the initial product, involving both large capital outlay and high operating costs, may be necessary to produce final products within current specification limits. Under these conditions it is desirable to identify ways of easing specification requirements that will increase flexibility, but at the same time maintain product quality.