Flight control

“ 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. ”

“ It's an enormously, enormously important issue for those of us who are involved in the aviation safety business to be dealing with, and it's something that I personallyspend a great deal of my time working on and something that the industry I think is more and more focusing on as one of the real places where we can make gains in safety.
So, we'll be talking here about a number of issues that relate to controlled-flight-into-terrain. These include issues that can be dealt with by airlines, by air traffic control authorities, by equipment manufacturers. ”

“ In the development of the models it had been absolutely necessary to develop some efficient automatic control, as they were far too small to carry an aviator, and the conditions of flight in the open air, even on the calmest day, were such that constant readjustments of the equilibrium were necessary. ”

“ At that date, 1893, an inventor doubtless could have secured a broad claim on a mechanism embodying the torsion-wing-and-double-rudder mechanism of control. But in those days aviation was pursued largely as a liberal study by scientific men who wished to hasten the advent of practical flight, by presenting important physical measurements and principles which could be freely employed by all. Accordingly the three-rudder system of control 232seems not to have been claimed by an inventor much before the close of the nineteenth century. ”

“ As winter was already well set in, we should have postponed our trials to a more favourable season, but for the fact that we were determined, before returning home, to know whether the machine possessed sufficient power to fly, sufficient strength to withstand the shock of landings, and sufficient capacity of control to make flight safe in boisterous winds, as well as in calm air. ”

“ Specifically, the NTSB requested the FAA to review ARTS III program for the possible development of procedures to aid flight crews when marked deviations in altitude are noticed by ATC, air traffic control. ”

“ The course of the flight up and down was exceedingly erratic, partly due to the irregularity of the air, and partly to lack of experience in handling this machine. The control of the front rudder was difficult on account of its being balanced too near the center. ”

“ 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. ”

“ Above all, flying has been rendered safe: with a sound machine to-day, and a competent pilot, it is as safe in the air as it is on the ground. So much for five years: but aeroplanes are still small, and their engine-power is low; and airmen may be likened perhaps to the first navigators of the sea. They paddled tiny boats, and found they could control them; then longed for larger craft, with which they might cross the ocean, and bear passengers from land to land. ”

“ The importance of this matter entitles it to rank almost as a National obligation; for the country in which facilities are given for the proper theoretical and experimental study of flight will inevitably find itself in the best position to take the lead in its application and practical development. That this must be considered a vital question from a National point of view is beyond dispute; under the conditions of the near future the command of the air must become at least as essential to the safety of the Empire as will be our continued supremacy on the high seas. ”

“ The flying machine which will navigate successfully in a perfectly quiet atmosphere may be unseaworthy, or rather, unairworthy, when a wind springs up, or the shifting of the wind may spoil all the air pilot’s plans. To add to his troubles, the aviator must move among air currents which change and change again in a moment’s time. As we study the difficulties of air navigation we will appreciate, more than ever, the wonderful patience, skill, and daring of the successful aviators.
The action of the air currents had first to be carefully studied before flight became possible. ”

“ To understand what this means it should be realised that, when such a machine is in flight say in war on a strategical reconnaissance, and carries pilot and passenger, the former can take it to a suitable altitude and then set and lock his controls, and afterwards devote his time, in common with that of his passenger, to the making of observations or the writing of notes. The machine meanwhile flies itself, adapting itself automatically to all the differences of wind pressure which, if it had not this natural stability, would need a constant action of the pilot to overcome. ”

“ So, in the case of aviation, man was long convinced, for no scientific reason, that flight was possible. With the first ascent by balloon came the imagined mastery of the air; later, the invention of flight that can be controlled at will. To-day we are still in the stage of colonization. The future resources of the air remain hidden from our view. ”

“ Its purpose is for use in great emergencies. Nor ought the aerial navigator, particularly [223] if he be alone, be forced to rectify his altitude continually by means of his propeller and shifting weights. He ought to be free to navigate his air-ship; if on pleasure bent, with ease and leisure to enjoy his flight; if on war service, with facility for his observations and hostile manœuvres. Therefore any automatic guarantee of vertical stability is peculiarly welcome to him.
You know already what the guide rope is. ”

“ The sighting arrangements are of a wonderfully complete character, as described elsewhere, but the irregular rolling movement arising from high speed is a nullifying quantity. It is tolerably easy for the aircraft, especially an aeroplane, to evade successful pursuit, either by rising to an elevation beyond the range of the gun, or by carrying out baffling evolutions such as irregular undulating flight, wheeling, and climbing. ”

“ By degrees, as air-traffic grows, new laws and regulations will need to be applied. But at present, save for restrictions such as have been cited, an aerial tourist wings unfettered flight. The motorist has a speed limit of 20 miles; but the airman, 3000 feet aloft, has none; and, save for certain areas out of bounds, the sky is free wherever he may fly. ”

“ In the operation of his ailerons, combined with the use of his elevator, a pilot is given means to balance his craft while in flight. One should not gain the impression that an aeroplane is threatening ceaselessly to heel this way and that. This is not so. The machine has a large measure of stability, apart from any manipulation of its controls, and needs balancing only when some disturbance of the atmosphere affects its equilibrium. ”

“ It is essential that the aggressive maneuver for a go-around is performed when at or near the minimum descent altitude or decision height, but when you are well away from it and commencing a go-around from more than a thousand feet away from such low altitudes, could be more gentle, and that may be an airline policy choice, but again have the data, use it, refine it, and then have confidence in how your pilots will perform. ”

“ 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. ”

“ But whether one feels flying fairly safe or not it must be admitted it is safer than it was. Recent steps have been made in securing true safety for the flyer in the last few years. Once attainment of something akin to it was merely a vague hope. If one flew one took the risks. Selah.
The problems of safety are concerned with the engineering problem of the motor and design of plane, the skill of the pilot and ground technique. Probably improvements in the power units will always be made. But it seems impossible that advances can go on so rapidly as they have in the last few years. ”

“ 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 ”

“ Today, our world is linked by a global air transportation system that enables us to travel safely and efficiently virtually anywhere in a matter of hours. Aviation technology has built on the foundations of manned airplane flight to provide advances in science, medicine, and many other fields. And mankind has ventured beyond the skies into space. ”

“ By "feeling the air" is meant the ability to meet any contingency intuitively and not until this is acquired can the student become an expert aviator. When it has been acquired, safe flying is assured and is dependent only upon the integrity of the planes, motor, and controls. By using the rudder discreetly and by banking simply far enough to partially offset the centrifugal force of turning, the use of the lateral control will not be necessary in still air. Even too short a turn can be corrected by a quick use of the rudder. ”

“ First he moves the Controls to see that everything is clear, for sometimes when the Aeroplane is on the ground the control lever or "joy-stick" is lashed fast to prevent the wind from blowing the controlling surfaces about and possibly damaging them. ”

“ At present all raids, reconnaissances and other duties entrusted to the aeroplane are subject to the condition that the operation must be completed in time to return to headquarters before dark; infraction of this condition is prone to result in serious losses, both of machines and men. It is abundantly clear that no such restriction should be tolerated, and the solution of the difficulty is to be sought in the provision of flight grounds, worthy of our present day aircraft. ”

“ Such a means of stopping a machine is often very necessary, particularly in cross-country flying, for a pilot may land, say, upon a sloping field, and find that his craft is running downhill quite beyond his control, and threatening to collide either with a wall or fence. ”

“ Of course, the aeronautics industry has benefited tremendously. Engines, automatic pilots, radar systems, flight equipment, capable of meeting the high standards required by space vehicles represent a great improvement over our already excellent aircraft. ”

“ 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 ”

“ If he is in the air we must manoeuvre our air craft so as to gain an advantageous position over him; one where we can shoot our machine guns or rifles while he is unable to use his similar weapons against us. That is where skill as an aviator and superiority of speed, climbing powers, and control of the machine will play a prominent part in deciding the supremacy of the air. ”

“ In order to meet the needs of large machines, we wished to employ some system whereby the operator could vary at will the inclination of different parts of the wings, and thus obtain from the wind forces to restore the balance which the wind itself had disturbed. This could easily be done by using wings capable of being warped, and by supplementary adjustable surfaces in the shape of rudders. As the forces obtainable for control would necessarily increase in the same ratio as the disturbing forces, the method seemed capable of expansion to an almost unlimited extent. ”

“ Under such circumstances it is impossible to tell what the plane is doing. It may be upside down or turning giant circles. Without instruments the pilot simply does not know his position in space—there are no outside landmarks with which to check. Of course, if one is really upside down for any length of time one’s feet drop back from the rudder and the safety belt tightens; or if in a skid a side blast of wind gives a belated warning, etc. ”