The 1,190th lecture to be given before the Society—and the 44th Main Lecture to be held at a Branch centre—" Nuclear Power in Flight", by Professor A. D. Baxter, M.Eng., F.R.Ae.S., M.I.Mech.E., at that time Director and Chief Executive, Rockets and Nuclear Power, and now Executive Director (Engineering), The de Havilland Engine Co. Ltd., was given under the auspices of the Swindon Branch of the Society on 2nd February 1961. Mr. S. R. Hughes, A.F.R.Ae.S., A.F.I.A.S., Chairman of the Swindon Branch, opened the meeting by welcoming the President of the Society, Dr. E. S. Moult, C.B.E., B.Sc.Eng., F.R.Ae.S., M.I.Mech.E., and other distinguished guests attending this first Main Society Lecture to be given at Swindon. Dr. Moult, who presided for the rest of the meeting, expressed his great pleasure at being present on this occasion. Introducing the lecturer, the President said that Profesor Baxter, as he was still known, was educated at Liverpool University and from 1930-34 served an apprenticeship with the Daimler Company. During this time he took his pilot's “A” licence and was commissioned in the R.A.F.O. After a year as Research Engineer with the Institution of Automobile Engineers, he joined the Royal Aircraft Establishment in 1935 as a Technical Engineer working on gas turbine research and later, rocket propulsion. From 1947 to 1950 he was Superintendent, Rocket Propulsion Dept., R.A.E., and then joined the new College of Aeronautics as Professor of Aircraft Propulsion, becoming Deputy Principal of the College also, in 1954. In 1957 Professor Baxter left the College of Aeronautics to join The de Havilland Engine Co. Ltd. as Chief Executive, Rocket Engine Division.

The Short SCI V.T.O.L. Research Aircraft, using four special Rolls-Royce RB.108 jet lift engines, which made its first flights in 1959 heralds a new method of taking-off and landing which may revolutionise the operational flexibility of aircraft of the future. The Short SC. 1 is the result of six years research and development by Short Brothers and Harland Ltd., who built and developed the aircraft, and Rolls-Royce Ltd. who designed and developed the special light weight turbojet engines which support the aircraft during the V.T.O.L. phase and which are shut down as soon as the aircraft has attained wing borne flight by the horizontal thrust from its separate propulsion engine. The SC. 1 is shown in hovering flight in Fig. 1.

While the subject of this paper is concerned with problems somewhat outside the scope of those which existed in the days of the late Roy Chadwick, nothing absorbed Chadwick's interest more than a seemingly intangible aircraft problem, and I am sure that had he been alive today he would have been deeply involved in the search for solutions to them.

He was without doubt a man of great talent, with an intuitive flair for design, and I join the many members of his staff who deem it a great privilege to have been associated with him for many years; and am honoured to have been asked to present this Memorial Lecture.

Following upon an experiment on the subjective effects of jet engine noise we have recently undertaken a similar experiment, this time on the subjective aspects of helicopter noise. The purpose of the earlier experiment was to determine the reliability of various methods of rating based on spectrum analysis, so far as comparisons between jet- and piston-engined aircraft are concerned. The main objective of the present experiment was to find if these methods are applicable to the pulsating types of noise characteristic of helicopters.