The CHAIRMAN opening the meeting, said he supposed that in aeronautics the helicopter was the dream which had taken longest to come true He believed that LEONARDO DA VINCI had dreamed it and he was certain that JULES VERNE had done so But there was a long period in a sort of borderland between dream and reality when helicopters were made which either did not fly or only just did so

In the past few years the helicopter had truly become a reality, there were many years of research and development ahead, but the helicopter had arrived In the Royal Aeronautical Society the helicopter had for long been one of the matters to which close attention had been given and in the past a number of eminent people had presented papers on the subject as well as on its sister, the “Autogiro,” before the Society and one or two eminent people had also given lectures against the helicopter and the “Autogiro”

Although barely two years have elapsed since the helicopter was first certificated for civil use, the problem associated with its operation are sufficiently well defined to enable their nature to be discussed with reasonable facility Actually, of course, there are twenty-six years, including many tens of thousands of flying hours behind this particular development, and it is quite logical therefore that the most advanced and successful type of helicopter to date embodies the basic and well proven rotor features of the Cierva Autogiro

There is still much to learn, however, and at this stage of development it has in many ways been advantageous that, so far, the field of operational use has been a professional one Difficulties have been minor rather than of a major category, but circumstances could easily have been otherwise had there not been constantly available the requisite background of skill and experience not only to cure, but what is of equal importance, to anticipate and prevent trouble before it could assume proportions of a serious nature Additionally the limited number of helicopters in use has encouraged and made possible a rather intimate and desirable liaison between constructor and operator, which in turn has given the aircraft a reasonable opportunity to establish itself and prove its value under strictly controlled conditions of inspection and operation

In a paper such as this, where I am asked to point a critical finger at the problems which we have to face in developing the helicopter for civil operation, it is inevitable that I should call attention to the shortcomings of the helicopters on which our experience rests so far We have to remember that it is only a few short years since the helicopter reached the stage when it could be put in the hands of operators, and that the types on which the whole of our experience is based were born in the stress of the war years when they had to be put into use just as soon as they worked reasonably well We have to admit that in many respects they are relatively crude in design, but, nonetheless, they have demonstrated that the helicopter is a practical transport vehicle and they have proved their worth in many fields The helicopter has definitely arrived and will take its place in Civil Aviation as complementary to the fixed wing aeroplane for normal transport operations, and in a sphere entirely its own where its special characteristics make it capable of doing work which no other vehicle can perform

LADIES AND GENTLEMEN,

Before calling on the first lecturer this afternoon, I would like to take this opportunity, on behalf of the Helicopter Association, of thanking the President and Council of the Royal Aeronautical Society for their courtesy, in inviting us to share to-day’s proceedings The idea of a full day’s discussion on helicopters originated with the R Ae S, but it can hardly be a coincidence that all those invited to read papers are members—I should say Founder Members—of the Helicopter Association, three of them being Council Members and one an ex-Council Member You are no doubt all aware that the Helicopter Association is of comparatively recent formation and owes a big debt of gratitude to the Royal Aeronautical Society, and other bodies for all the help and guidance they have given in the three years since the Association was incorporated

The success of the helicopter today is primarily the result of a background of rotary-wing experience covering many years of research into the problems of the gyroplane This simple form of rotorcraft, proposed by JUAN DE LA CIERVA, was developed to a stage at which vertical take-off and landing were normal maneouvres and were no longer exclusive features of the helicopter Only the ability to hover remained as the unique advantage of the power-operated rotor—an advantage for which a heavy penalty had to be paid The general problems of the helicopter for civil use are concerned mainly with an alleviation of the penalty that hovering has incurred

The technical problems confronting the helicopter designer are very clearly enumerated in Captain LIPTROT’s paper, and Wing Commander BRIE has drawn attention to a number of considerations of importance to the operator

With some of these problems I have dealt in an earlier paper, and in order to avoid repetition I propose to leave out from this discussion points which have already been raised

Rotating-wing aircraft in forward flight are subject to vibrations for reasons which are fundamental and we must not therefore expect the elimination of these symptoms but only their reduction to generally tolerable proportions We need, therefore, more accurate methods of recording and analysing vibrations in helicopters in terms of component frequencies and amplitudes, and in addition we must have generally agreed standards for comfort, i e, limiting vibration levels as a yardstick both to makers and users of these aircraft

As my contribution to this afternoon’s proceedings, it is my task to give you a brief account of the Cierva “Air Horse” This machine has the distinction of being the world’s largest helicopter undergoing flight testing

Following the recent S B A C exhibition at Farnborough, I have heard many kind and unkind expressions of expert and inexpert opinion, but the lowest common denominator seems to be that it is an “astounding contraption” Faced with this challenge, my purpose this afternoon is somewhat apologetic, namely, to show that it is neither astounding nor a contraption In fact, we, in the Cierva Autogiro Company, have persuaded ourselves that God decreed three rotor helicopters All others are merely attempts by men to cheat His divine laws

The “Air Horse” design arose primarily as an answer to the demand for large loads It was realized that difficulties in helicopter construction increased in proportion to rotor diameter and nothing was therefore more natural than to increase the number of rotors