FLYING THE AIRPLANE
=Starting Off.=—The first thing to do before starting off in an
airplane is to inspect carefully everything 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.
[Illustration:
(_From “How to Instruct in Flying.”_)
FIG. 32.—Airplane in flying position just after starting.
This cut also illustrates proper landing attitude, since airplane is
just skimming the ground.]
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 raise the tail off the ground and place the wings edgewise
to the wind while they will not offer resistance to the acquiring of
good rolling speed. Within a few seconds the machine will have attained
on the ground a velocity not less than the low flying speed; it will
not rise, however, until the tail is lowered by pulling the lever
back. When the necessary rolling speed is attained pull the lever
softly backward; the tail at once drops, the wings increase their angle
and lift and the machine will rise, the lever being held in a fixed
position (see Fig. 32). The distance between the point of starting
and rising will be 100 yd. or more and will occupy from 5 to 10 sec.
depending on the wind.
The change from flying position to climbing position is only a slight
modification involving only a slight pulling back of the control lever
and holding 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
therefore 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.
[Illustration:
(_From “How to Instruct in Flying.”_)
FIG. 33.—Airplane in gliding position, approaching a landing.
Note that its attitude relative to line of flight is similar to “flying
position,” line of flight however being inclined.]
=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; second, because you can always kill extra height by a spiral or
two better than you can regain it. Have height to spare when landing.
To come down throttle down the engine and push the lever softly forward
until the proper gliding angle is obtained (Fig. 33). The reason for
throttling down the engine is: first, that you do not need its thrust
when you are coasting down because gravity furnishes all the necessary
velocity; second, if you glide or dive with the motor wide open high
speed 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 to operate.
[Illustration: FIG. 34.—Attitudes of an airplane in flight.]
Maintain the proper gliding speed to within 5 miles an hour of what
it ought to be as it is the speed which determines the proper gliding
angle. The revolution counter will indicate what the speed is 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 the machine level and it may be
necessary to operate the rudder after touching the ground in order to
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 the wings may be presented to the air and the machine be slowed up
rapidly. Some machines are fitted with brakes on the wheels to assist
in the quick 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 the 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, the 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 imminent pancake open up the engine to keep machine
flying, put the machine into a flying position, then throttle down
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.
[Illustration:
(_From “How to Instruct in Flying.”_)
FIG. 35.—Bad landing, Type 1—the “pancake” landing.
Line of flight is downward; angle of incidence large, hence speed is
slow; but there is too much downward momentum and landing gear will
break. Should line of flight arrow point upward, airplane as shown
would then be in climbing position. ]
3. 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 second bounce; then reland.
[Illustration:
(_From “How to Instruct in Flying.”_)
FIG. 36.—Bad landing Type 4—machine not level.
Wheels do not touch ground at same time, and one may smash.]
4. If at the moment of landing the rudder is turned causing machine to
swerve, or if the machine is not level, a side strain will be placed
upon the landing gear and the wheels will buckle (Fig. 36).