It is a special honour and privilege to be asked to give the Wilbur and Orville Wright Lecture this year. My good friend, John Seekings, has reminded me that 1972 marks the 100th anniversary of the publication of Around the World in 80 Days. That celebrated voyage by Phineas Fogg is particularly appropriate to our contemporary world of air transport. Many of the problems he faced are still with us—and we will probably have them 100 years from now.

It was also just about a 100 years ago that the Russian scientist, Mendeleyev, described the skies as “air oceans”. That description seems particularly apt today. And it is the basis for my thesis that we are now adrift on the “air ocean”. We are adrift because we have the technical means to tie the world together aeronautically but we cannot seem to agree on a heading to follow.

Technology has compressed a trip around the world from the 80 days of Phineas Fogg to a matter of hours. When we consider that it has only been 45 years since Lindbergh's historic flight across the Atlantic, the advances of technology seem even more staggering. But, while we have performed some technological miracles, we have also engendered some of the most difficult and complex problems since man rolled the first wheel downhill.

Louis Brennan, CB, was born in Castlebar, County Mayo, in 1852, and whilst he was at a very early age his parents emigrated to Australia where in due course he attended the College for Artisans in Melbourne. I know little of his youth but I understand that he became interested in watch and clock making and that his first adult achievement was the designing and making of a civic clock of Big Ben status.

What next I know of Brennan's activities is from the notebook of Professor William Kernot of Melbourne University who, incidentally, was Australia's first engineering graduate. This shows calculations on the performance of the torpedo and is dated 1876, so Brennan must have been quite young when he conceived this idea.

With some assistance from Professor Kernot and others, he designed and built a prototype which carried out such successful trials in 1879 that the British Admiralty were informed and they invited Brennan to England and financed the further development of the torpedo.

It was of great interest to learn, from their most comprehensive paper “Helicopters in the Royal Navy“*, of the authors’ views on the SAR role, and especially of their outlines of the most beneficial features for ideal SAR aircraft (pages 472-476). This note refers to some aspects of the latter that were not mentioned, on which it would be interesting to know the opinions of the authors and of other helicopter pilots.

Some six years ago, I learned from the US Coast Guard of a system they had adopted with considerable success, to minimise the above hazards- At that time, I drew this arrangement (illustrated in the accompanying sketches) to the attention of RN and RAF officers concerned with rescue, but the idea received little support, for which there may be two reasons.

The American aircraft had, I believe, winch lines 200 ft long, whereas that on the Wessex was only 106 ft long. The Sea King (winch line 245 ft) had not then become operational. For their ideal SAR aircraft, the authors propose one 300 ft long. Thus, on the Wessex, the risk of fouling an obstruction would have been approximately doubled. As the longer lines now available and being proposed would go far to minimise this risk, perhaps the US system may in future be considered more favourably.

There is some evidence to indicate that injuries associated with parachute opening shock are much less frequent than injuries associated with the acceleration loads imposed by ejection seats, even though the stresses presumed to be induced in the human body may often be of the same order. Since all such data is based on operational experience, the details are necessarily vague, and it is hard to draw firm conclusions.

The Aeromedical Research Laboratory, USAF, as part of its studies of aircrew injury, decided to see whether there was any difference between the dynamics of parachute opening when used with a rigid anthropometric dummy of the type normally used to obtain opening shock data, and a human parachutist whose body is naturally more resilient.

This paper gives details of a method for measuring local heat transfer rates and shows that the results obtained are in fair agreement with the expected values.

The experiments were performed in the 8 in x 3·5 in supersonic intermittent wind tunnel at Queen Mary College (University of London). A maximum Mach number of 1·6 is obtainable at which the free stream Reynolds number in the working section is 4·92 x 106 per foot under normal conditions. The tunnel has a running time of approximately 20 seconds at a Mach number of 1·6.

The series of heat transfer measurements were restricted to flat plate conditions with non-constant wall temperatures.

Excitation of subharmonic resonances is one of the serious vibration problems which often have to be overcome in the development of high speed machinery. Such resonances have been observed, for example, in gas turbines(3), in rotor systems(4) and in the geared drive of a rotating kiln(5).

The subharmonic resonance of order 1/2, of a single degree of freedom system with viscous damping, is investigated for the case of a centrifugal disturbing force. The restoring force characteristic is of the non-odd form and its asymmetry is expressed in terms of the static deflection parameter. The Ritz averaging method, with a five term approximation, is used for the theoretical analysis. Numerical results are presented for the undamped case and are compared with analogue computer solutions.

The choice of the Ritz averaging method is determined mainly by its adequate accuracy at larger magnitudes of non-linearity. It is also more versatile than other methods and in a previous application(6) to a system with an asymmetrical restoring force it produced satisfactory results.

Little has so far been written to specifically cover this subject*. Many papers and books make passing reference to it; many management courses touch lightly upon it. However, most writings and teachings on “salesmanship” deal with the conventional salesman with a detergent packet in hand, a foot in the door, and a “management objective” of umpteen calls per week. Nowhere have I found a reasoned analysis and exposition of the problems faced by those of our select band who try to sell high cost capital equipment, mostly in the export market.

Selling aero engines is unusual in that the aero engine is only an accessory to the aircraft —yet an accessory whose performance can often dictate the size and shape of the aircraft, as well as its profitability in operation. Nevertheless much of the techniques of selling this equipment is common to other prime movers and also reads across both to the aircraft manufacturer and to the smaller accessory supplier; many of the general principles apply across a wide field of capital goods.