In the following paper it will be convenient to adopt the definition of inverted flight used by the Accidents Committee in R. & M. 617 (Advisory Committee for Aeronautics), “Reports on the behaviour of aeroplanes when flying inverted, with special reference to some accidents on ‘A,’” which was as follows:—“ In normal straight flight the pressure of the pilot on his seat is equal to his weight. During inverted straight flight he would hang on his belt with an equal force. It is therefore considered useful to call inverted flight such flight only as occurs when the weight of the pilot no longer presses on his seat.”

It is very kind of you to invite me again to address the Scottish Branch of the Royal Aeronautical Society, and I am glad to do so at this the opening meeting of what promises to be a highly valuable session.

I will not excuse my temerity in coming here to-night for two reasons. First, since I am no longer in direct touch with aviation I do not claim first hand knowledge of detail, my interest in what we all believe to be one of the greatest of modern developments is still unabated. And secondly, because aeronautical progress must be assisted by open discussion of its difficulties, and it may be of value, whether you agree with them or not, to express some personal ideas from the outside angle of a year's private membership of the House of Commons as a preface to your more technical meetings.