SAFETY IN THE AIR

Evening Post, Volume CIV, Issue 91, 14 October 1922, Page 18

SAFETY IN THE AIR

STABrLITY OF MACHINES

TESTS AND CALCULATIONS

OPINIONS OF AN EXPERT.

Recent air smashes have roused general interest in the problem of saiety in the air. Dr. PiercVj Director of the Aeronautical Laboratory at East London College, has given his view of the problem in an interview with an "Observer" representative,

"Given a good pilot, reliable engines, and a low landing speed," he said, "safety in flying depends on the strength of the machine and its stability in flight. The design of aircraft calls for special care. In other engineering structures, where weight does not matter much,, a large margin of strength is allowed to cove*' deficiencies of design, workman- ] ship, or, materials. The 'factor of safety' | ought to be greater still in the case of : aircraft, for the loading of the wings may easily be more than doubled in the course of necessary manoeuvres. Unfortunately weight must be kept down. Experimental records are reassuring, and there is no real difficulty in designing a light aeroplane of ample strength. "The time is past for tolerating brilliant performance obtained at the expense of safety. In the pioneer days, when aeroplanes consisted largely of string, when engines were small, and when there was little prospect of leaving the ground at all, the case' was different; but we cannot afford nowadays to repeat the lamentable history of our last airship. "A "stable aeroplane is so proportioned that, if it is disturbed in flight by a gust, it tends to right itself of'its own accord. An unstable aeroplane makes a constant demand on the pilot. It is no easy matter to ensure an all-round measure of stability,; on the other hand, the methods for investigating the stability of a new machine have been worked out and, though highly technical, are perfectly straightforward. In mj opinion ah aeroplane should not be allowed to leave the ground with its stability untested. The practice of plodding through' the necessary tests and complicated calculations is happily gaining in popularity, but I think is not yet universal." .THE NEEDS OF RESEARCH.

"Is the development of aeronautics in this country impeded by the want of capable investigators?" "Yes and no. From the point of view of talent, there is no reason why this country should not have retained the foremost position it recently occupied. In Professor L. Bairstow this country undoubtedly possesses the greatest authority in the world on the problems of aerodynamics. There are many other whose capability for carrying out important investigations should be regarded as a national asset. Unfortunately, the Air Ministry does not appear to be in the position to help research effectively. One would think, however, that even the small fund at its disposal could be applied' to do something to assist vital investigations. lam afraid that we shall not be in the running with other nations unless the output of research is brought to the pre-war level." The Aeronautical Laboratory at East London College includes in its equipment a large 4ft wind channel installed at the suggestion and with the financial help of the old Seaplanes Committee of the Admiralty, and is one of the oldest in the country.

Dr. Piercy, who has been in charge of tie laboratory since its expansion in 1916, is well-known for. his researches iv aerodynamics, and is one of the two persons on whom London University has conferred the Doctorate of ■ Engineering for such work. . A THOUSAND DESIGNS. Asked about the work done in the laboratory, Dr. Piercy said:— "Nearly a thousand different designs of wings have been submitted to us for wind channel tests since 1914. One of the m6dels which passed through our hands became the most efficient wing known during a, period in the early part, of the war. Several of the high-lift designs tested were adopted by the Government for seaplanes during the war, and others were used for land machines. The first quadruplane, for instance, was jmt through its model stage here." "Have you done any research for commercial purposes?"

"A' good deal. One of the' most extensive investigations we have undertaken was in connection with the birdshaped 'Allula' wings. We are completing another piece of work on . the question of big machines. Few firms, however, can stand the delay and expense of such preliminary experiments. The task is to wean, the aeroplane from the extravagance and instability which were features of war-craft, and the laboratories of the country have yet to build up the fundamental knowledge required. During • the war there was no time for it; since, there ha.ye been no funds."

"Does the laboratory now get any money from the Government?"

"Unfortunately, no," said Dr. Piercy. "The Seaplanes Committee assisted the laboratory in the past, but the Air Ministry, apar^ from paying the bare expenses of certain investigations, has given us no money. We hope, however, that the Department of Scientific and Industrial Besearcb will help us in our impending experiments."