Flight maneuver

“ Hereby the force of the wing and the resistance become balanced; so that, manifestly, the air is beaten by the wing with the same force as the resistance to the stroke.’
He concerns himself also with the most difficult problem that confronts the flying man of to-day, namely, landing effectively, and his remarks on this subject would be instructive even to an air pilot of these days: ‘Now the ways and means by which the speed is slackened at the end of a flight are these. The bird spreads its wings and tail so that their concave surfaces are perpendicular to the direction of motion ”

“ In this stage of his tuition, the pupil must learn also to make a vol-plané, or descent with his engine stopped. The essential point to be borne in mind, here, is that an aeroplane will continue in flight, and remain under control, even when it is no longer propelled by its engine. But what the aviator must do, should his engine stop through a breakdown, or should he himself switch it off, is to bring the force of gravity to his aid, and maintain the flying speed of his craft by directing it in a glide towards the ground. ”

“ Aircraft, while on final approach to land, or while landing, have the right-of—way over other aircraft in flight or operating on the surface. When two or more aircraft are approaching an airport for the purpose of landing, the aircraft at the lower altitude has the right—of-way, but it shall not take advantage of this rule to out in in front of another which is on final approach to land, or to overtake that aircraft. ”

“ But as soon as this stage is passed, i.e. when a second wing-beat is possible without the legs touching the ground, progress becomes very rapid, because the increased forward velocity facilitates flight, and three, four, or more double beats follow each other in one attempt, maybe awkward and unskilled, but never attended by accident, because of the caution exercised by the bird. ”

“ Curtiss’ method of control led the way to the modern type of wing aileron and the general system of control was basically the same as that in use today.
POWER FOR THE AIRPLANE
Going back to the four forces that govern the flight of a plane, we find thrust pulling the plane forward. Thrust is the force that keeps the plane in the air; without it the airplane could not leave the ground for sustained flight. Thrust is created by the propeller. The propeller blades function in the same manner as the wings. ”

“ Instead of the wind possessing32 the speed, in this instance, it is you who provide it. The motor of an aeroplane, driving the propeller of the machine, turns this at 1000 or more revolutions a minute, and causes its curved blades to screw forward through the air as they turn, like those of a ship's propeller through water—or a gimlet into wood. The propeller, as it bores its way into the air, draws or pushes the aeroplane across the ground; and the speed grows rapidly until the air, sweeping with an increasing pressure beneath the planes, becomes sufficient to bear the craft in flight. ”

“ Fig. 17.—Diagram showing that in fast airplanes wings are small; in slow airplanes wings are large.
(Above) Small wings; speed 115 mi. per hr.; for fighting. One seat.
(Below) Large wings; speed 80 mi. per hr.; for reconnaissance. Two seats.
Regarding area of wing surface, the pilot does not have to worry in a flight since he can do nothing to change it anyway. All he needs to know is that in different airplanes small wing area accompanies high speed and small weight-carrying capacity, as in the case of the Fokker and Sopwith speed scouts (see Fig. 17) . ”

“ To illustrate, in a wagon drawn uphill by horses the wheels which support the wagon do not exert any more support than on the level, and the entire force to make the wagon ascend is supplied through extra hard pulling by the horses. Thus in a climbing airplane the propeller furnishes all the climbing force and lift is no greater than in horizontal flight. In fact, the actual lift force may be even less, as the weight of the airplane is partly supported by the propeller thrust which is now inclined upward slightly. ”

“ A pilot must be able to do more than cause his aeroplane to ascend and to alight: he must have means to check the lateral movements which, under the influence of wind gusts, may develop while the biplane is in flight. At the rear extremities of the main-planes as illustrated in the photograph facing page 34—and marked D.D.—are flaps, or ailerons, which are hinged so that they may be either raised or lowered. These ailerons are operated, through the medium of wires, by the same hand-lever which governs the movement of the elevator. ”

“ There were there possibilities which the pilot could have tried: - continue flight on one engine, land with wheels up or land with wheels down. He elected to do the latter. [5] First contact with the ground was made at a speed and in an attitude which prevented the maintenance of continuous ground contact with a resultant loss of braking. ”

“ With the one hand-lever, as we have shown, it is possible for a pilot to control the rise and descent, and also the lateral movements of his machine; and there remains only the steering to be effected—the movement from side to side, from right to left, or vice-versa. At the rear of the biplane, as shown, facing page 34 will be seen two vertical planes, E.E. These, being hinged, will swing from side to side; and they exercise a sufficient influence, when working in the strong current of air that blows upon them when a machine is in flight, to steer it accurately in any direction. ”

“ No turn can be made by the use of the rudder alone. The plane must be banked with ailerons before the rudder will have any turning effect.--Get me?"
"I get the last part. Guess I'll have to do some studying."
"Everybody has to do that. But I'll lend you some books, so you can bone up on the theory of flight. What I said just now amounts to this: if you don't bank enough you send your plane into a skid."
"Just like an automobile skids?"
"Yes. But of course the danger doesn't lie in hitting anything as in a car. A skidding plane loses her flying speed forward and drops into a spin. ”

“ At three thousand feet altitude the Pilot is satisfied that he is now sufficiently high to secure, in the event of engine failure, a long enough glide to earth to enable him to choose and reach a good landing-place; and, being furthermore content with the steady running of the engine, he decides to climb no more but to follow the course he has mapped out. Consulting the compass, he places the Aeroplane on the A–E course and, using the Elevator, he gives his craft its minimum angle of incidence at which it will just maintain horizontal flight and secure its maximum speed. ”

“ The old way of flying had made all aeroplanes easy prey to anti-aircraft guns and to attacking machines, but when it became necessary to dart out of the range of any enemy who had suddenly revealed his presence with bursting shrapnel, or when only a quick maneuver could prevent him from blocking the way home, the old-fashioned, steady, level flyer and slow climber became deathtraps. ”

“ Experience, the researches of science, and the growing skill with which aircraft are built, stand between the airman and many of his previous dangers. The aeroplane to-day, one of the structural triumphs of the world in its lightness and its strength, has a factor of safety which is sufficient to meet, and to withstand, not merely ordinary strains, but any such abnormal stresses as it may encounter—and which may be many times greater than the strains of normal flight. ”

“ It is possible, however, in view of the extreme unfamiliarity of the experience of spinning in a transport airplane and of the special difficulties presented by instrument conditions and rough air, that even a highly expert pilot might lose as much as 5,000 feet before being able to complete the maneuvers for checking the spin and recovering from the subsequent dive ”

“ The daring aviator, who was flying a new two-seater fighting machine with a twelve-cylindered engine, capable of giving over fourteen hundred revolutions a minute, seemed perfectly oblivious of the danger he was in, as seen by those below, for he careered through space at a speed varying from eighty to nearly one hundred and twenty miles an hour, and performed the most amazing spirals, twists, and gymnastic gyrations imaginable. ”

“ In the stoppage of its motor, when a craft is in flight, several factors need consideration; but one should clearly be understood: even if his engine does fail while he is passing through the air, a pilot is not helpless, nor does his machine fall to the ground. As he flies, of course, it is the thrust of his motor, acting through the medium of the propeller, that keeps his craft moving forward; and so long as this thrust is there, forcing his planes against the air and causing them to lift their load, the machine will fly ahead. ”

“ The craft must also fly in a reasonably straight line toward the goal, and should it be deflected for any reason and go off at a tangent, the flight, no matter how successful otherwise, [Pg 16] will not be counted. In case of a collision between air-craft, the race is repeated. The responsibility for adjusting the power, arranging the steering-gear, and giving direction to the flight at the start is entirely in the hands of the young engineer himself. ”

“ The aviator himself is attached to the parachute through the shock-absorber sling, by means of a harness which he wears constantly throughout his flight, so that in the event of trouble he only has to jump overboard and the parachute automatically does the rest. ”

“ This is comparable to the ineffectiveness of a rudder on a too slow-moving boat. If a plane stall with out motor occurs so close to the earth that there isn’t time to recover control, a hard landing results. ”

“ The fact which is the basis of all aeroplane flight is that a perfectly horizontal plane, free to fall through the air, has its time of falling much retarded if it is in rapid horizontal motion. This is what makes gliding possible. Now let the plane which is being propelled in a horizontal direction be slightly tilted up, so that its front, or leading edge, is higher than its back, or trailing edge. The reaction of the air can then be resolved into two components, technically called 'lift' and 'drag'; lift, which tends to raise the plane, and drag, which retards it in its forward motion. ”

“ As the rotary motion of the arrows increases during the fall, the direct line of flight becomes more pronounced until at last they assume a vertical direction free from all wobbling, so that when they alight upon the target they are quite plumb. ”

“ The forces which determine the descent are fixed by the velocity and the angle between the planes and the path of flight. Manipulation of the rudders and main planes or even the motor may be practised to ensure lancing to best advantage; but in spite of these (or perhaps on account of these) scarcely any part of aviation offers more dangers, demands more genius on the part of the operator, and has been less satisfactorily analyzed than the question of “getting down.” It is easy to stay up and not very hard to “get up,” weather conditions being favorable ”

“ I had nothing to do other than to give occasional attention to the revolution counter, altimetre, and speed-dial. The motor was running with perfect regularity. The propeller was turning over at twelve hundred revolutions per minute without the slightest fluctuation. Flying is the simplest thing in the world, I thought. Why doesn't [69] every one travel by route of the air? If people knew the joy of it, the exhilaration of it, aviation schools would be overwhelmed with applicants. Biplanes of the Farman and Voisin type would make excellent family cars, quite safe for women to drive. ”

“ It is interesting to watch their flight; for it seems to consist of a series of maneuvers, as they fly, now against the wind, when they always ascend, thus taking advantage of its force; now before the wind, when they descend, that little exertion may be needed to keep them above water; then, whirling rapidly, like a hawk, to exhaust their speed when wishing to check their rapid flight. ”

“ After a careful look around to see that no other planes are landing, taking off, or in the air near by, the pilot opens out the engine, the roar increases its pitch, the plane moves slowly along the ground, gathers speed and rises smoothly into the air. ”

“ To alight with an airplane the pilot—supposing his descent to be voluntary and not compelled by accident or otherwise—surveys the country about him for a level field, big and clear enough for the machine to run off its momentum in a run of perhaps two hundred yards on its wheels. Then he gets up a good rate of speed, points the nose of the 'plane down at a sharp angle to the ground, cuts off the engine, and glides. The angle of the fall must be great enough for the force of gravity to keep up the speed. There is a minimum speed at which an airplane will remain subject to control. ”

“ To shut off the engine at precisely the right moment, (p. 114) to choose an angle of descent that will secure the greatest speed and at the same moment bring you to your landing place, to change at the most favourable time from this angle to one that will bring you to the ground at the most gentle of obtuse angles, and to let your machine, weighing perhaps a ton, drop as lightly as a bird and run along the earth for several hundred feet before coming to a full stop, are all features of making a landing which the aviator has to master. ”

“ But the pupil was not permitted to land a machine until near the end of his course; for next to getting out of a tail spin, a dive, or a side slip, landing was the hardest task in flying. Statistics show that more aviators have been killed in making landings than in any other way. Many of the accidents, of course, were [42] caused by the nature of the ground, for when the engine of the aeroplane stops, the aviator has to volplane or glide down wherever he can. ”