History of Aviation - Chapter 4
FLYING THE AIRPLANE
Starting Off.-The first thing to do before starting off in an airplane is to inspect carefully every thing about the machine and assure yourself that _ it is in perfect condition.
When all is ready to start turn the machine directly against the wind; this is done in order that the rise from the ground may be more quickly made with the assistance of the wind under the wings, and it has a more important advantage in the fact that if you try to get off the ground across the wind the machine will be very hard to balance. Birds also take the air directly against the wind even though for the moment this carries them in a direction toward some supposed enemy, and it is a ~ fundamental principle in airdromes. Keep the machine pointed into the wind for the first 200 ft. '~ of altitude (and similarly in landing face the wind when within 200 feet of the ground). In case the engine should fail before a height of 200 ft. is reached, never turn down wind as this is extremely dangerous.
Assistance will be had for the start from the mechanics, or if away from the airdrome from bystanders. Have each assistant in his proper place before starting the engine; one is to start the propeller and the rest to hold back the machine until ready to let go.
In order to get off the ground you will want good engine power; it takes considerable thrust to
accelerate an airplane on the ground to its flying speed; in fact the first flying machine of the Wrights had to use an auxiliary catapult to furnish the thrust necessary to get them into the air. Making sure that the motor is giving full power raise the hand as a signal to the attendants to remove the chocks and let go.. As you start rolling forward push the control lever forward which will tail off the ground and place the wings e~ to the wind while they will not offer resistance the acquiring of good rolling speed. Within a seconds the machine will have attained on ground a velocity not less than the low flying it will not rise, however, until the tail is low by pulling the lever back. When the necessary rolling speed is attained pull the lever softly ward; the tail at once drops, the wings increase their angle and lift and the machine will rise, lever being held in a fixed position (see Fig. The distance between the point of starting and ris ing will be 100 yd. or more and will occupy 5 to 10 sec. depending on the wind.
The change from flying position to climbing position is only a slight modification involving only slight pulling back of the control lever and hold it in fixed position; the motor may in some machines simply be opened out when its increased power will make the machine rise; however, there is only one speed at which the climb will be fastest and there-fore it is well to know what is the proper speed for climbing; the motor is then opened out full and the airplane operated to give the proper speed corresponding.
The pupil should rise to the height of at least 100 ft., as any less is useless and nothing will be learned from landing. In the case of cross-country flying the pilot will rise to the height of 2000 ft., circling over the field rather than flying off in a straight line so that preparatory to his start he always has the flying field in reach.
Landing.-Proper landing is the most important thing in airplane flying. The pilot in turning his machine downward toward a landing spot from flight will choose a distance from the field equivalent
to the proper gliding angle of his machine. If the gliding angle is 1 in 7 he must not turn downward any further from the field than a distance greater than seven times his altitude or he will fall short. It is safer to come closer to the field before turning downward for two reasons: first, because you may
not be gliding at the best gliding angle; because you can always kill extra height by a spiral or two better than you can regain it. Have to spare when landing.
To come down throttle down the engine and the lever softly forward until the proper gliding is obtained (Fig. 33). The reason for throttling down the engine is: first, that you do not need thrust when you are coasting down because gray furnishes all the necessary velocity; second, if glide or dive with the motor wide open high will result, resulting in strains on the machine especially on the moment of leveling out again; third at this high speed the controls become stiff operate.
Maintain the proper gliding speed to within 5 miles an hour of what it ought to be as it is the which determines the proper gliding angle. The revolution counter will indicate what the speed or the air-speed meter may be used. Arrange to come on to the field facing directly into the wind, which may be observed by watching smoke or flags below. In landing against the wind you are again copying the practice of the birds. When you come to within 15 ft. of the ground pull the lever softly back until the machine is in its slow-flying' position, which should be attained 5 ft. above the ground (Fig. 34). Hold the stick at this position of horizontal flying; no further movement of the lever is necessary except to correct bumps, for which purpose it would be held lightly for instant action.
The aileron control must be used here to keep machine level and it may be necessary to operate the rudder after touching the ground in avoid swerving; in fact some machines are provided with a rear skid which steers for this purpose.
In rolling just after landing keep the tail as close to the ground as possible without causing undue bumping, so that the maximum resistance of wings may be presented to the air and the machine be slowed up rapidly. Some machines are with brakes on the wheels to assist in the retardation of the roll. Landing is one of the biggest problems in aviation and is a hard thing to learn because it is done at a high speed especially in fast military machines such as the Fokker, Nieuport, etc. Landing is more of a problem than it used to be in the early days when, for instance, Wrights were able to land without any wheels at all on mere skids because their machines were not fast.
The following are examples of bad landings:
1. The pancake results from allowing the machine to get into its rising position when it is landing (Fig. 35). There will be a perpendicular bounce and on the second bounce the running gear will break. In order to get out of an immanent pancake open up the engine to keep machine flying, put the machine into a flying position, then throttledown again and land.
2. Another type of pancake results from bringing the machine out of its gliding position at a point
too far above the ground when the machine will drop due to lack of speed and break the running gear. To avoid this open motor full, thus regaining speed and flying position; afterward throttle down and reland.
2. A third type of bad landing results from failure to turn the machine out of its glide at all, so that it glides straight downward until it touches the ground. This is the most dangerous case of all the bad landings. To cure it open up the engine after the first bounce, regaining flying speed before the bounce; then reland.
3. If at the moment of landing the rudder turned causing machine to swerve, or if the machine is not level, a side strain will be placed upon landing gear and the wheels will buckle (Fig. 36).