Britten-Norman started out as converters of Tiger Moths for export to New Zealand as top-dressers. As new aircraft came into that particular scene (Cessna 180s) we turned our attention to spray equipment. As luck would have it during our researches into available ground spraying techniques, I ran into Edward Bals who had perfected some very simple rotating gauze atomisers to make possible ultra low volume spraying applications upon, for example, orchards.

Thanks to the efficiency of his rotary atomiser he was able to dispense with almost all the carrier liquid of which hundreds of gallons were used on each acre to secure proper coverage by substituting a mist of small uniform sized droplets carried in a dratt (not a blast) of air.

It is now 72 years since the Wright Brothers made the first controlled flights with a manned heavier-than-air machine, and I am deeply conscious of the great honour conveyed by the invitation to deliver this 64th Memorial Lecture commemorating their great achievement.

Their research and development work provides a classic model of a combination of the scientific and practical approaches to the solution of a major problem. However, it is fascinating to look back to those very different days at the turn of the century, and see how incompletely they foresaw all the consequences of their own efforts. Contemporary evidence suggests that their vision was confined to certain secondary uses of the aeroplane, such as military reconnaissance, sport and exploration.

This paper can be divided into four parts; firstly, a tribute to R. K. Pierson, then a brief historical survey of events that have affected the RAF and industry, leading up to where we stand today; and finally, some thoughts on the future based on the twin aims—which I am certain you will endorse—of maintaining a healthy and viable aircraft industry in the United Kingdom, and of satisfying the future needs of the Royal Air Force at the lowest possible cost. I am going to concentrate on the military side.

A great deal of interest has been shown in recent years in the problem of flexibility in spacecraft structures. Much published work has been devoted to analysing the dynamic interaction between deformation of flexible appendages and attitude control systems. A limited number of publications have sought to find ways of providing some form of active control of flexible motion. Where this has been attempted idealised systems consisting of flexible coupled pendulums or rotors have been considered.

The problem of flexibility may be tackled in three ways. Where the flexure can be shown to be secondary in nature, careful design of the attitude control system can ensure that interaction is kept to a minimum. To this end surveys of structural flexibility effect in spacecraft are invaluable to the design engineers. Where the flexural motion has a more dominant effect, as will follow from the inevitable increase in power requirements for communications, then a more direct approach will become necessary.