You have honoured me and my associates in asking me to present your Sir Henry Royce Memorial Lecture. When I saw the list of my predecessors, and their contributions to aviation, I must say I have joined a very select company and can only hope that I shall be able to justify your faith.

When I first selected my title, I was not aware that the ‘Well Tempered’ description had been used previously by Arthur Raymond in his 1951 Wilbur Wright Memorial Lecture to the Royal Aeronautical Society. With sincere apologies to Mr Raymond, who was for many years responsible for engineering leadership of the Douglas Company, the selection of ‘Well Tempered’, which he derived from Johann Sebastian Bach, still seems most appropriate. I hope he will forgive me for using it again.

The Royal Aeronautical Society and the Weybridge Branch have given me a great honour in inviting me to deliver this unique lecture in memory of one of its distinguished Honorary Fellows.

The life and achievements of Sir Barnes Wallis (Fig. 1) have been well chronicled and broadcast. It is with some trepidation, therefore that I make this contribution, but as one of many at Weybridge who worked directly under his authority, I would like in paying this tribute to feel that I am representing all of them. In a lecture of about 75 minutes it is not possible to give proper justice to the work of a man who devoted something like 70 years to engineering design. He was already 16 years old and in his last year at school when the Wright Brothers were the first to fly, in 1903; he was still in full-time employment when Concorde flew in 1969. Although not involved in either of these epics, his own career was studded with many achievements, and even after his retirement he continued to work on visionary projects.

In the spring of 1980, a long range derivative of the L-1011 TriStar entered commercial airline service with an extended wing span and a digital Active Control System (ACS). The extended wing span improves fuel efficiency by 3 to 3½ % due to a higher wing aspect ratio and lower induced drag. The digital ACS provides load alleviation functions by symmetric motions of the outboard ailerons which relieve the loads induced by the increased wing span. This load relief minimises the amount of structural modifications required to the basic L-1011 wing to accommodate the increased wing span.