Even the best pilot may make a mess of his machine if his engine goes "dud" over a forest, city, swamp, or other impossible landing-place. It is his business more or less to keep clear of such tracts when flying. But one of the tests of a good pilot is whether or not he can shut off his engine in the air, pick out his particular field below, taking into account that he must land against the wind, then by a series of gliding turns find himself just coming out of the last turn in front of the fence. He may make a gentle little "zoom" over the fence, using every last bit of flying speed for the last kick, and settle down gently on the other side. One test of instructors in Canada, before they were allowed to take up pupils, was to make three perfect forced landings in succession--one of them as the pilot came out of the spin. With his head still reeling he must pick out his landing-place and make it. The difficulty is, of course, not to undershoot, to fall short. It must be remembered that in case of actual engine failure there is no motive power, and if a man calculates his distance too short, he has nothing left but to make his landing where he may be. He has lost his height and his chance to reach other fields. He may find himself rolling into the fence of the field he was trying for. Or, equally bad, he may overshoot. The distance was shorter than it looked, he has more height to lose than he thought. He can gain nothing by sticking the nose down, because in his plunge he gains speed which will carry him too far on the ground. He may bowl over the fence, or, if there is a field beyond, make the next field. More often he finds himself in a patch of woods with a broken airplane. It is possible that on a turn, a gliding turn with the engine shut off, the pilot may lose his flying speed. Unless he is experienced, he does not realize that on a turn the machine presents more surfaces to the air and greatly increases the air resistance. It is likely to stall unless a safe margin of speed is maintained. The dangerous part of this is that very often the machine will lose its speed when only a hundred feet from the ground, approaching the field. There is no chance to pull it out of a spin unless the pilot is alert and realizes that he has lost speed, and noses down before he spins. Often he spins, and a fall with an airplane from a hundred feet is just as nasty as it can be.