The Chairman, in opening the meeting, said that it was a pleasure to welcome at that meeting of the Association a distinguished engineer from France, Monsieur Rene Dorand, who was well known internationally as a pioneer of the helicopter M Dorand’s name became associated with that of Louis Breguet in 1931 when they built in collaboration a helicopter with co-axial rotors That machine had achieved considerable success both in hovering and in forward flight It established international records for a flight duration of more than one hour and a forward speed of more than 100 k p h, and it also demonstrated an autorotative descent from 100 meters

M Dorand became a graduate engineer in 1921, and in the same year took a diploma in electrical engineering He then joined the Louis Breguet Aircraft Company as a graduate engineer and became Technical Director of the Breguet-Dorand Helicopter development group

Attempts at human flight go a long way back into history First success did not come by use of man’s own power for propulsion but by the use of balloons for lifting Later gliders were made for descending flight It was only when a much greater source of power than man’s own was developed that flight with heavier than air machines became really successful It was not until the 1930s that much serious attention was given to man-powered aircraft flight With the aeronautical knowledge that was then available successful man-powered aeroplanes were developed and built which flew a few hundred yards Little attention appears to have been given to the possibility of a manpowered helicopter, possibly because it did not appear to be as promising a line of development as the aeroplane

The present interest in man-powered flight has led to the consideration of whether man-powered flight can be accomplished by rotary wings If this could be done, it would be extremely convenient and in many ways much more attractive than man-powered flight by fixed wings or even semi-fixed flapping wings Support in the air by a rotor enables the forward speed to be as small as zero and, one would hope, as fast as a bicycle Not only it is attractive from this point of view, but such a machine could be small and compact and it is initially imagined as something on the lines of the small one-man helicopters under development in the U S A and France and possibly in other countries

Study of the problem involves two basic considerations Firstly, it must be made clear exactly what power can be made available from the human body to drive the rotor Secondly, it must be discovered how this power can best be applied in order to get the most out of it, in the hope that it will be sufficient for free flight by man-power

The Chairman, in opening the meeting, said that one of the important aspects of aerodynamics was the study of the interaction between two component systems Thus much experimental work was devoted to the investigation of interference effects between, for example, a wing and a body, or one wing and another wing, or a wing with a jet stream issuing from its surface, or the effect of ground proximity

In the rotary wing field, it was necessary to have a knowledge of the aerodynamic interaction between two rotors for the successful design of tandem rotor helicopters With the modern trend for rotorcraft to have fixed wings and become more like aeroplanes, it was necessary now to have an accurate knowledge of the mutual interaction between a wing and a rotor Tonight, this aspect, as well as other aerodynamic aspects of the Fairey Rotodyne, was to be discussed by the lecturer, Mr K T McKenzie