THE AIRWAY

Sun (Auckland), Volume III, Issue 686, 11 June 1929, Page 14

THE AIRWAY

By "THE ROC" Flying Through Darkness Or Fog

riE hazardous flight through dense fog and rain made on Friday from Hamilton to New Plymouth by the Hamilton airman, Captain Maegregor, suggests another of the problems confronting cross-country flying, and indicates the importance of a reliable "weather forecast whenever there arises any doubt concerning the activities of the elements. There are instruments which guide pilots through fog and darkness, but while these devices help in straight flying they offer no assistance in finding the landing-ground and coming down on it.

In all light planes there are dials tn the instrument board which show not only the functioning of the motors, but also the position of the plane with relation to the earth. When a pilot dips into a fog bank or cloud the mist swirls around him, almost hiding the ends of his wings. He is alone in a white wilderness in which all sense of direction or relative position is lost. He then fastens his eyes on his instruments, and by them keeps his plane on a level keel. Without them he would probably stall. With the proper use of instruments he is safe as long as his fuel lasts or until he finds a hole in the fog and manages to land.

In the earlier days, when flying was done only in the daytime and in clear weather, there was little need for instruments; but in America and on the Continent, with the advent of night flying on mail routes and the demand for uninterrupted service, much more than the instinctive skill of the pilot became necessary. He is so often faced with the task of flying blind, which means flying by the use of instruments alone. His most important instrument in this work is the turn and bank indicator. This shows him when his plane tips to one side or the other or begins to turn, movements which cannot be detected in fog by instinct. With these he uses his inclinometer, which shows whether the nose of the plane is rising or falling. It is usually the tendency on the part of a pilot who cannot see the earth to pull back gradually on his stick until the plane stalls and falls off. The inclinometer enables him to prevent this. The turn indicator and compass show him his direction.

With these, instruments any tendency of the plane to turn right or left, up or down, or to bank can be instantly detected. But it is a strange fact that on a long flight a pilot becomes so weary that his instruments appear to be deceiving him. He feels that he is stalling or turning when actually he is in straight, level flight, and his instruments so indicate. On an ocean flight two years ago, the pilot felt that his instruments were off, and he fought an almost overpowering desire to fly by instinct, which he knew would be fatal. Finally, in desperation, he took his hands off the controls and let the plane fly itself for a time, until he gradually recovered his poise. It is nerve-racking to fly through the night or fog, hour after hour, watching the dials, and requires great self-control. Another aid which is being perfected is the directional radio beam. With this instrument the pilot receives from a fixed point toward which ha is flying a radio impulse which actuates a dial and shows whether he is on the left or right of his course. Then it is only necessary to change the compass course enough to bring the plane back until the indicator returns to its normal position. The signal may also be an audible one transmitted through receivers on the head of the pilot. This system was of great aid on several of the Pacific flights. In Britain there have been experiments with an electric cable stretched around a field at some distance from it. It can be detected by an instrument on the plahe, and the pilot will know when he receives the signal that he has passed over a point at a certain distance from the field. If he

| goes on he will receive a signal when j he passes over the field and over the I cable the other side of the field. Supj pose that there are several of these i cables sending out signals at regular j distances from the field, the pilot will, ; as the last one is passed, know that he is within gliding distance of the field. Safety in flying in bad weather in the future will rest largely upon such instruments, and the pilot of the large transport will have to be a man of greater experience and training. Fog will not be a serious obstacle to be avoided, and it will not be necessary to skim along under a low ceiling, j hedge-hopping over the trees, in moj mentary danger of hitting something : unseen. The pilot will be able to j leave the perils of low flying and go up to a safe distance until his instruments tell him he is at his destination. Ice Still a Menace There is one other danger in flying that must be overcome, that of ice forming on the wings. Kingsford Smith and Co. had trouble in this respect, during the Tasman flight. When an airplane gets into a cloud at certain temperatures, or when rain or sleet falls on a plane at temperatures close to the freezing point, ice

is apt to gather on all parts of the plane and particularly on the leading edge of the wing, where it causes the most trouble. A plane is not brought down as much by the weight of ice on it as by the ice destroying the characteristics of the wings and ruining their efficiency. Ice can gather in a few minutes and cause a plane to lose altitude even with full throttle.

There are a number of experiments now under way to meet this difficulty. It is possible that some substance may be found to which ice does not cling and which can be used to coat the wings, wires and struts of a plane. But is can be seen that flying is becoming much more of a science and less a form of acrobatics. The pilot in the future will distrust his instincts and rely on his instruments.