Aeroplane Construction and Operation

by John B. Rathbun

Ground Instruction. Before attempting flight, the student should be thoroughly versed in the principles an constructional details of the aeroplane and the aeronautic motor. He should know how to take down, time and repair every type of motor with which he is likely to come into contact. He should be able to tell at a glance whether the machine is rigged or trued up properly, and have a general knowledge of the underlying principles of aerodynamics. The study of these subjects is the function of the ground school. At this school the student should learn the assembling and adjusting of the aeroplane structure and its balance.

Types Suitable for Pilots. There is a great diversity of opinion as to the type of man best suited for flying. In this country the government requirements regarding age and physical condition are very exacting, while in Europe it has been found that physical condition is not an index to a man's ability as a pilot. Many of the best French pilots were in such bad shape as to be rejected by the other branches of the army. Our men are well under 30 years of age, while in European service there are many excellent pilots well over 40. It is almost impossible to tell from external appearances whether a man can become a good pilot.

In general he must be more intelligent and better educated than the average infantryman. He should not be subject to an attack of "Nerves," nor become easily rattled, for such a man courts disaster in flying. Many exhibition flyers of reputation have proved absolute failures in military service. A knowledge of mechanics will be of great benefit and has been the salvation of many a pilot in active service. Automobile or motorcycle experience is particularly valuable. Recklessness, or a dare-devil sort of a disposition, are farthest from being qualifications for an aviator. Such a man should not be permitted to fly, for he is not only a constant menace to himself but to everyone else concerned.

Learning to Fly Alone. It is with the greatest hesitancy that the author enters into a "Ground course" of flight instruction. I can, however, list the principal things to avoid and some of the things to do, but this will never take the place of actual field instruction and experience. The first and last thing to remember is to "Proceed slowly and with caution." Never try a new stunt until you are absolutely sure that you have thoroughly mastered the preliminary steps in straight flying. Over-confidence at the beginning is almost as bad as no confidence at all, and the greatest difficulty met with by instructors during the first solo flights is to keep the student from imitating the maneuvers of the more experienced flyers. Spend plenty of time rolling or "Grass-cutting" before attempting to leave the ground. Be sure that you can handle the rudder with accuracy, and at fairly high speeds before attempting to lift. A few days spent in sitting in the machine (motor dead), and acquainting yourself with the controls is excellent practice and certainly is not a loss of time. With the machine in the hangar, move the controls for imaginary turns, dips and other maneuvers so that the resistance, reach and limit of control movement will come more naturally when the machine is moving.

During the ground rolling period, the elevator or stabilizer should be set so that it is impossible to leave the ground, and the motor should be adjusted so that it cannot develop its full thrust. This will provide against an accidental lift. Be easy and gentle in handling the controls, for they work easily, and have powerful effect at high speeds. The desperate fervor with which the beginner generally yanks at the "joystick" is generally the very reason for his accidents. Do not start off at full speed without first getting used to the effect of the controls. Learn to find the location of the various devices so that you can reach them without looking or without fumbling.

The First Straight. By adjusting the stabilizer and elevators so that the latter has a greater degree of freedom, and by changing the motor so that it can be run at a slightly higher speed, we are in a position to attempt our first flight. Be careful that the adjustment will limit the climb of the machine, and choose only the calmest of weather. It should be remembered that the aeroplane will get off the ground at a lower speed than that required for full flight at higher altitudes, this being due to the cushioning effect between the wings and the earth. A machine traveling at a speed capable of sustaining flight at a few feet above the earth will cause it to stall when it is high enough to lose this compression. The adjustment should be such that the machine cannot rise above this "Cushion," and in this condition it is fairly safe for the beginner.

In making the first runs under the new conditions of adjustment, the student should learn to manipulate the elevators so that they will hold the tail up in the correct position, that is, with the chord of the wings nearly horizontal. Do not allow the tail skid to drag over the ground further than necessary. At this point the student should be strapped in the seat by a quick-detachable safety belt.

Now comes the test. Get under full headway with the tail well up, taking care to run against the breeze. The speed increases rapidly, then the motion and jar seem softer, and the motor ceases to roar so loudly. There is now a very distinct change in the note of the motor. You are off. At this point a very peculiar illusion takes place, for your elevation of a few feet seems about a thousand times greater than it really is. With this impression the student usually tries to correct matter by a sudden forward push on the control lever causing fine dive and a smash. It must be borne in mind that only the slightest movement of the controls should be made, and if this does not prove sufficient after a moment or so, advance them still further but very gently. Sudden movements must be avoided. At first the "Hops" should not extend over a hundred yards or so until the student is sure of his controls. Little by little they can be increased in length and height. He should practice for some time before attempting a flight of more than a mile. By this time, the student will have learned that the landing is by far the most difficult feature in flying, and he should practice this incessantly before trying flights in windy weather.

The machine should be headed directly into the wind, both in getting off and in landing, especially in the latter case, as a sudden following gust will tend to stall a machine or upset it. With a head wind, the lift is maintained at a low speed and hence is an aid in a safe landing. When flying in still air there is little if any use for the ailerons, but in gusts the student will need their aid in maintaining lateral balance. After the rudder and elevator controls have been well learned the effect of the ailerons can be tried. Gusty or squally weather must be avoided at this point in the training, and no turns should yet be attempted.

When the student attains heights greater than a few feet he should take great care in obtaining a sufficient ground speed before trying to get off, for if lifted before the full flying speed is attained it is likely to stall. Fast climbing at sharp angles is dangerous unless a sufficient ground speed has been attained. Sustentation is due to forward speed, and this must not be forgotten. The quickest climb for getting over trees and other obstructions is obtained by gaining full speed on the ground before the climb begins, as the power of the engine is aided by the momentum of the machine.