Some Unconventional Aircraft
Authors: Wimperis H.E. 
Published: November 2014

THE use of a rotating wing in place of a fixed one has long had a peculiar fascination for inventors, no doubt due in the main to the attractiveness of hovering flight, as it is called. The ability to hover carries with it the ability to alight gently, and in a limited space—an enormous advantage in foggy weather. Our own Government has taken a keen interest in the possibilities of the rotating wing. Soon after the Great War the Air Ministry started the experimental building of the Brennan helicopter. This was a four‐bladed device with a central engine and gear drive to two wing propellers. Much time and much money were consumed, but even after many years of effort the world was still without a helicopter which had made a cross‐country journey of even 10 miles; and I might have named a much shorter distance than that. Then there came the able young Spanish engineer, de la Cierva, with his autogiro and its ingenious and attractive system of hinged blades. To embark on the investigation of the rotating wing in flight is an entrancing adventure. The controls are different, new forces are brought into play, the technique of flight has to be learnt afresh. At the end of the research you may be no further on, so far as practical equipment is concerned, though you should be wiser; but there is always a chance that a pass may be found between the mountains of difficulty which will lead to the “Promised Land.” Most human adventures bring the adventurers in the end to the spot from which they started, and not infrequently the adventurers are content enough, after their hardships, that that should be so. Señor Cierva was adventurous to the point of temerity, and in the end he achieved what he sought—a new form of flying machine which really did fly. With great pertinacity he built machine after machine until, in the end, aided I am glad to add by British support, he constructed a machine which could fly across country in secure stages for thousands of miles. This, however, promising as it was, was not really the end of such a quest. A most difficult part had still to come, viz., the relatively humdrum requirement that the economics of autogiro transport must be such as to enable it to rival the conventional type of aircraft. In this stage we now are; it looks at present as though we may have to be content with a drop in top speed, rate of climb, and fuel economy in order to reap the great advantages of the autogiro in respect of safe landing. In striking this balance of merits, it must be borne in mind that the great advantage of safety in landing is now claimed also by the conventional type merely unconventionalised to the extent of being fitted with the Handley Page auto‐slots. If the rotating wing should fail to make good through the autogiro, will it do so through the Isacco helicogyre? This machine is an autogiro in which each of the four blades carries a small engine and airscrew. One is being built in this country, and is expected to be ready for flying tests this year. Such a machine, if it flics at all, should be able to ascend vertically as well as descend vertically. If it did this successfully at not too great an economic cost it would have merits with which the conventional type of aircraft, slotted or otherwise, would find it difficult to compete. But the path is likely to be long and difficult. In the last twenty years or so there has been time to discover and correct most of the bad habits of the ordinary airplane. British civil aviation as represented by Imperial Airways has had not a single fatal accident to any passenger for over three years—a splendid record. With these new flying machines we have to start again, and to start from scratch—to discover painfully and irritatingly how many little things there are to go wrong when there is no previous technique to guide us. With the autogiro most of our trouble, almost all of it, has been due to small breakages or failures of parts subjected to forms of stress not met with in any previous machines, whether for flying or for anything else.