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

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