Aerial Acrobatics Are Necessity for Flyers.

Star (Christchurch), Issue 18959, 4 January 1930, Page 19 (Supplement)

Aerial Acrobatics Are Necessity for Flyers.

Stunts —Foolish and Useful.

(Written for the “ Star ** by

T. J. C. MARTYN.)

A THOROUGH knowledge of I aerial acrobatics is the j most valuable that a comraer- j cial pilot can acquire. Stunts, so called, may be divided into I two categories—the foolish and the I useful. The foolish ones are those done close to the ground; for, no matter how expert a pilot is, it is only a matter of time before a slight error of judgment will cost him his life, or at best a serious accident. The useful stunts, such as looping, spinning, rolling, Immelmann turns, etc., were developed in the wartime exigencies of pursuit flying, and are performed usually at a safe height —that is, at an altitude sufficient to enable the pilot to right his machine without running the risk of a crash. But to the ground observer, stunts may seem quite unnecessary in this day and age of commercial aviation. This, however, is not the case. Stunt flying is every bit as much of a science as, for example, aerodynamics. There is a wrong way and a right way to loop. One way can strain the machine seriously; the other will put no more strain on it than it will normally encounter riding through rough weather. Moreover, although stunt flying is usually supposed to relate to air fighting, it has a definite peace-time value. The pilot who knows how to stunt, how to get his machine into every conceivable position and difficulty, and how to get it out again, is the one who is the most to be trusted with the lives of passengers, and the one who is never likely to be caught unawares in one of those sudden, dangerous situations that all pilots sooner or later experience. He knows what to do in almost every crisis, and he knows it because his judgment has been formed and tested in the arduous school of scientific stunt flying. Suppose you are a ground observer, and accompany an instructor of stunt flying. Perhaps you learnt to fly years ago; perhaps you have flown several hundred hours in the mail service. It makes no difference. You will be treated as a novice, whether the object is a thrill or to qualify for passenger or pursuit flying—a test that ought universally to be applied, but at present is net. On reaching a height of two or

three thousand feet, you will experience nothing more exciting than learning how’ to fly straight, and you will be shown the effects of too much right or left rudder or too much right or left bank. That is easy. Next come turns to the right and left, and as you improve the turns become steeper and steeper until they are vertical. In a vertical turn an extraordinary thing happens. The rudder becomes the elevator and the elevator the rudder. In fact, the more a ’plane is inclined laterally, the more the controls change places, so that each turn in a different degree of bank is different, and the difference is detected bv feel, or in instrument flying by the indicators of the pilot’s dashboard: but. when you have progressed to the vertical bank stage, the instructor will suddenly kick on top rudder; the ’plane stalls and goes into a spin. Then comes the quiet voice of the instructor over the telephone: “ Switch off the engine. Push the stick forward. Centralise the rudder bar,” and in a moment the ’plane is flying on an even keel. There is no hurry, no excitement (except for an embryo airman), lor there is no danger. Landings will be the next and longest lessons of all. When you have been taught to judge distances, you will be permitted to land straight into the wind. The next thing that will probably happen is to have the engine cut out when the ’plane is vertically above the airport at a height of, say, 1000 ft. The instructor has purposely cut the engine out, and is telling you to land on the aerodrome. That will be your first lesson in spiralling—losing height by circling down, either in one direction or alternately to the right and left —and one way or another you w’ill have to get into the aerodrome. Spot landings—landings oh a mark on the ground —and cross-wind landings follow. The latter are done by sideslipping into the wind and landing on one wheel, immediately after turning into the wind —the most difficult of all landings in which a head-to-wind landing is impossible for lack of time and space. You can now fly -straight, turn in both directions, at any angle, land regardless of wind or on a mark on the airport. You are now ready to learn stunting. The instructor no longer shows you how to do anything; he merely directs you, and never comes to vour assistance, other than verbally, unless it is absolutely necessary to avoid a crash. When the ’plane is soaring about 3000 ft up. his voice will come over the ’plane telephone: “ Put your nose down to ninety (or whatever the speed is for your particular ’plane). Keep the rudder bar straight and pull the stick back towards you with a firm movement. When you see the ground, switch off the engine.” You push the stick forward, and the 'plane gathers speed, and when the air speed indicator shows ninety you will put the stick back as far as it will go. The ’plane ri«es swiftly, the earth disappears as though it had suddenly shot off from under you, and you are conscious of a vast expose of sky and clouds rushing to meet you, and the next moment the earth is directly below you. If this is your first loop, •you are probably so excited that you have forgotten t.o switch off the engine, and the ’plane begins to tear down at a terrific speed. In a moment the instructor’s voice is calmly telling you, “ Off with the engine ” Your first loop | In some ways a loop is the easiest

; all the stunts and after you have ane twenty or so of them they cease > yield any thrills. But at some time - other the instructor will almost cerlinly wait until you are about onerird up on a loop and then cut the igine out. He wants to see if you ill keep your head. The ’plane, derived of its power, does not have peed enough to complete the loop and tails; that is, for an infinitesimal jeond it hangs in the air and then ither whips over and goes down in a pin or begins to tail slide (go down til first), from which position it may o into a tail spin, giving a most unomfortable feeling to the novice. If ou know what to do and do it, the istructor will remain silent; if you lose our head his voice will soon calm you nd instruct you in what you should e doing. And within a minute the jlane will once more be sailing up on level keel. On another occasion the instructor rill wait until you are on top of a loop nd suddenly kick on right or left udder, with the result that the ’plane alls out of the curve sideways and apidly goes into a spin unless you ake immediate steps to counteract it. Jut by this time you are getting .ardened to surprises of this kind and. ave control of the ’plane every minute. So the time comes when you are aught to roll—a side loop executed by putting on sharp rudder and bank one ,fter the other and then pulling the tick back. In a training dual conrol ’plane the movement is slow and umbersome, but in a fast pursuit plane, which you will shortly fly, the iiachine whips over in the twinkling of n eye and may even go over twice beore you can stop it, after which it tails into a spin. In fact, a spin is isually the way out of all unconrolled stunts, but as the spin is eas*ily topped there is never caus,e for alarm. Next comes the Immelmann turn, inrented by the famous German war ace. t is merely a sideslip fro/n a stall and las the advantage of bringing the plane around in the opposite direction o which it was going. There is the ail spin, one of the most difficult of ttmts. Some machines will not do t and invariably complete the initial tall into which it is normally necesary to put the 'plane. You perform he stunt by getting the machine to fide backward and then putting on >pposite bank and rudder, as in a forvard spin. To get out of it you traighten out the rudder bar and bring he stick to the centre of the cockpit >ut not backward or forward until the ;pin stops, when you pull it back to :ause a stall. The falling leaf is perhaps the most iifficult stunt, with the exception of an jutside loop—one in which the 'plane s dived down on its back and climbed nit to the top. What makes the fating leaf so difficult! is that the 'plane las to be stalled,* with the engine off, n a horizontal position; that is, flying level with as little forward speed as possible. In this position the 'plane s balanced laterally as if on the edge 3f a razor, and the successful completion of the stunt calls for exceptional skill. As soon as the 'plane is brought to a bait you push the stick over to one side sharply and at the same time kick on the rudder. The controls are limp and it feels as if nothing much has happened, but the machine heels over on one side; as soon as it does you have to bring the controls over to the other side and the ’plane should recover and list over to the other side. The effect is that of a leaf falling through tfie air, swinging first in one direction and then in the other. The great difficulty is in keeping the nose of the ’plane up and in preventing it from falling too far over to one side. All through this stunting’ period you will be practising forced landings. You will find yourself coming out of a spin. You open the throttle but the engine is “ dead.” The instructor tells you to pick out a field and land on it. This you do. One day when you are getting fairly expert, you will be taking off from the airport and at about 300 feet up your engine will cut out. Man s normal instinct is to try to turn and get back on the airdrome, but this is almost invariably fatal. Possibly more deaths in the air have been caused by this foolishness than by anything else. The only thing to be done is to go straight ahead and make the best landing possible, and as you have by this time been taught to land on a pocket handkerchief you should find no difficulty in making this difficult forced landing. It is, however, the one test in which the instructor will not stop to instruct you; if you do not do the right thing, right away, he will, and if you “ freeze ” on to the stick you will probably get a swift knock over the head with a heavy stick that the instructor keeps by him for such danderous pupils. Solo is child’s play. In reality you have flown the machine yourself for perhaps fifty hours. You can loop, spin and roll as easy as turn. You are thoroughly air-broken. Then w’hen your chest is puffed out to its maximum your instructor will suggest some more dual-control. He wants to make sure that you are doing everything the way he taught you. So up you go and are put through your paces, so to speak. As usual he will surprise you with engine failure in an awkward moment, only this time he wilf indicate a field for you to land in. It is the prize field of all. It probably has high trees around it, a high fence between them on one side and high bushes between them on all the others, and the field itself is about half an acre or less. You will not, if you are smart, bother about the wind, and will circle about the field. Seeing a gap in between the trees, you will make for it. Your wheels have to scrape the tops of the low bushes and you will have to make a “ pancake ” landing, one with no forward speed. This done you will have to get out of the field again, which i» almost as difficult as getting into it. If you are successful you can be a* sured that you will be passed as a firs* class pilot; for the field has been artificially created, in all probability, so that only an expert pilot can get into it and take off from it. Since the scientific knowledge of stunting—knowing how much each control does and why—makes for safe flying, the observer on the ground should feel assured that in this way pilots are training for the day when they will take him to Berlin or Paris or London, and he may be further assured that no matter what ills befall the ’plane en route, his life will be as safe in their keeping as it is in the hands of a locomotive engineer. (Anglo-American N.S.—Copyright.)