Signal Corps numbered one hundred and sixty officers and men. At the
time the armistice was signed more than thirty thousand pilots had
been trained. They were trained in great numbers under high pressure.
We did not have the machines to train them in or the instructors to
fly with them. We had not the experience in wholesale training of
flying-men, and yet we turned out vast numbers. It was a question of
getting the men through their flying and getting them overseas as
quickly as possible. We had no adequate methods of inspection of
machines, and no laid-out course in flying-training. We had to learn
by our own experience, in spite of the fact that England at all times
gave unstinted aid.
The wonder is really that we did not have more flying accidents. There
were few men in the country who really understood what conditions
tended toward a flying accident. There were few who had ever gone into
a spin and lived to tell about it. At that time a spinning-nose dive
was a manifestation of hard luck--like a German shell. If you once got
into it, it was only the matter of waiting for the crash and hoping
that the hospital might be able to pull you through.
Toward the end, of course, this situation had been largely overcome,
the Gosport system of flying had been tried out, and there was a vast
increase in the knowledge of flying among the instructors and pupils.
The spin had been conquered, training was on a sound basis, and
accidents were being rapidly cut down.
One of the most obvious ways to cut down crashes was by making sure
that the pilot was in good condition physically. Flight surgeons
assigned to every camp were detailed to make a study of the very
delicate relationship between a sick and stale pilot and the crash. It
was discovered, for instance, that a man who went up not in the best
condition multiplied by many times the ordinary hazards in the air. It
became the duty of these surgeons to conduct recreation and exercises
so that pilots would always be in good trim.
Flying for an early solo pupil is the greatest mental strain that a
man can experience. Every moment the fact that he is up in the air,
supported only by wood, wires, and fabric, may be on his mind. He is
making desperate efforts to remember everything his instructor has
told him since he started his dual. He tries to keep that nose on the
horizon, the wings balanced, and the machine flying true. He is in
fear of stalling and consequent loss of control. He goes into his
turns, hardly knowing whether he is going to come out of them, and
noses down for a landing, mentally giving prayer, perhaps, that he
will come out all right. He can't possibly remember everything he has
been told, but he tries to salvage as much knowledge as possible to
make a decent landing.
These experiences tend to bring about two conditions, aerophobia
(fear of the air) and brain fatigue, both resulting in complete loss
of head on the part of the pilot and inability to react to impulses.
Nothing is more likely to produce immediate and fatal aerophobia than
the sickening sight from the air of a crash, yellow wings flattened
out against the green ground a thousand feet below. A comrade, a
tentmate? The pupil looks at his machine, sees the wires throbbing,
and watches with wonder the phenomenon of rushing through the air--he
may let his imagination dwell too long.
During his first hour's solo a swift stream of hundreds of impulses is
borne along the nerve centers to the brain of a pupil. It is like the
pounding of heavy seas against a light sea-wall. His brain reels under
the repeated shocks and the pupil falls into a detached stupor. He
waits while his engine throbs ahead, and lets the machine fly itself.
He seems to take no active participation in the operation, and unless
he recovers control of his brain and his machine it is a crash.
Physicians then have the problem of learning from a dazed and perhaps
badly injured man how it happened. He can recall nothing, and seldom
knows when he lost control.
These are the things that happened when this country was hastening
fliers overseas. As a matter of national necessity it was essential
that as many men as possible be put through their dual and solo flying
and sent across to the other side. It was better for the country at
large to turn out five hundred pilots a month, say, with 5 per cent.
of casualties, than one hundred a month with one-half of 1 per cent.
or less of accidents. These figures do not represent the actual
conditions, but they picture the problem.
Now the civilian who would take up flying has just as much time as he
wants to spend in learning to fly. He is paying for his instruction,
and he should continue it for perhaps fifteen to twenty hours of dual
instruction. He should fly the machine with an instructor in it, and
really get accustomed to the feel of the air. He should become
sensitive enough so that he can differentiate between the tight, firm
touch to a machine flying under complete control and the slack
movement of stick and rudder of a plane very nearly out of control. He
should recognize these danger signs and know how to correct his flying
position.
Dual flying should be continued up to the point where the pupil flies
without thinking, when it becomes the natural thing for him to use
both stick and rudder to correct a bump, and when he thinks no more of
it than riding over a rut in a road. He should be able to tell by ear,
when volplaning, whether or not he is maintaining sufficient speed to
hold it in the air. He should be acquainted with the principle of
spinning, and should have had some experience in taking a machine out
of a spin.
The treacherous thing about a spinning-nose dive is that, to come out
of it, a pilot must put his stick forward, not hold it back, in spite
of the fact that the machine is falling nose first and spinning at the
same time. A spin is possible only from a stall, and only when the
stick is back and rudder in either direction is given. The position is
an easy one to get into from a steep turn. Air resistance against a
machine turning becomes greater, it slows down the speed, decreases
the lifting power of the planes. The result is that the nose falls
slightly. The pilot moves the stick back to lift the nose, and in
doing so pulls up his elevators, offering still more resistance to the
air, and checking the speed. The effect becomes cumulative; he tries
to hold up his machine, and he has stalled. In a last effort to check
the spin he kicks on the rudder, and the thing is done.
The rudder and elevators have formed a pocket in the tail plane, which
is like the spoon on a trolling-hook. The pocket is off-center and the
air rushes into it as the machine topples over and plunges down. It
imparts a twisting motion, which in a turn or two develops into a
throbbing spin. Picture the pilot, trying to lift the nose of his
machine by holding his stick well back and wondering why the nose does
not come up. The pathetic thing is that so many hundred men have
thought their salvation was to hold the stick back.
The only possible thing to do in this case is to break the pocket. Put
the stick forward to neutral, or even farther if need be, and opposite
rudder. The machine will come out in three-quarters of a turn with
practice, into a straight-nose dive. Then ease the stick back, and
this time the nose comes up and the machine flies on its course.
Instructors who have taught their pupils this before they let them go
solo have saved many, many lives.
It is reasonable to say that there are no fatal accidents except those
from a spin, but, like all general statements, that is open to
contradiction. A nose-high side-slip may be fatal, but generally the
pilot pulls himself out of it. There may have been men killed in
landing accidents, but one seldom hears of them. Men have been killed
trying to loop off the ground, and Vernon Castle was killed doing an
Immelmann turn at fifty feet to avoid another machine. These are the
exceptions. The common or garden variety of accident is from a spin.
The spin once conquered, the air is conquered.
One hears about stunting, and the accidents which result from taking
chances in the air. There may be two opinions about whether for the
flying of the future it should be necessary to loop, to roll, to half
roll, and stall turn, or even to spin. As to looping and rolling, the
question of the type of machine to be flown will determine that
largely. There are many machines which cannot be looped. The large
naval flying-boats, for instance, describe a circle two thousand feet
in diameter for each turnover--it is almost obvious that not much
stunting is done on these boats. A small scout or sporting plane can
loop and come out higher than it went in.
There is certain value in practising such maneuvers if the machine
will permit it. In battle they are, of course, essential. In peace,
however, they may be valuable for the very fact that it accustoms a
pilot to unexpected changes in the air. He gets used to the idea that
he can pull himself out of any position, given air enough, and he will
never be afraid. He becomes orientated on his back, does not lose his
head, and simply waits with confidence for his machine to come around.
This means that if he is suddenly overturned by accident, or for a
minute or two loses control, he knows that his condition is temporary
and that he must simply "carry on."
Army pilots who have had a good course in stunting would certainly
recommend the same for civilian pilots. That does not mean that it
would be necessary, or even advisable. There have been accidents due
to stunting by both inexperienced and experienced pilots. Generally it
is a matter of altitude, for with sufficient height the greenest pilot
can come out of anything, if he does not lose his head.
For the man who would be the pilot for a large commercial plane, such
as the Glenn Martin bomber, the Super Handley-Page in England, or the
Naval Curtiss flying-boats, no stunting is necessary. He may sit in
the cockpit of his machine, and ramble off mile after mile with little
motion, and with as little effort as the driver of a railroad
locomotive. He has a large, steady machine, and there will be no
obligation for him to spill his freight along the course by turning
over in midair.
Whatever opinions may be held regarding the advisability of teaching
stunting to a civilian pilot, there can be no question that a civilian
pilot must have a long and thorough course in the very gentle but
essential art of making forced landings. The problem is that of
controlling a machine with its engine cut off, to have complete
control of it within the radius of its gliding distance. Again, the
dart gliding to its uncertain landing. In the hands of an unskilled
pilot, an airplane gliding without power is a very dangerous thing. He
may pile up the machine against some farm-house, fence, haymow, or
clump of woods, smashing it badly and injuring himself. Or he may,
through inexperience, lose flying speed in the course of his descent
and topple over into a spin.
Even the best pilot may make a mess of his machine if his engine goes
"dud" over a forest, city, swamp, or other impossible landing-place.
It is his business more or less to keep clear of such tracts when
flying. But one of the tests of a good pilot is whether or not he can
shut off his engine in the air, pick out his particular field below,
taking into account that he must land against the wind, then by a
series of gliding turns find himself just coming out of the last turn
in front of the fence. He may make a gentle little "zoom" over the
fence, using every last bit of flying speed for the last kick, and
settle down gently on the other side. One test of instructors in
Canada, before they were allowed to take up pupils, was to make three
perfect forced landings in succession--one of them as the pilot came
out of the spin. With his head still reeling he must pick out his
landing-place and make it.
The difficulty is, of course, not to undershoot, to fall short. It
must be remembered that in case of actual engine failure there is no
motive power, and if a man calculates his distance too short, he has
nothing left but to make his landing where he may be. He has lost his
height and his chance to reach other fields. He may find himself
rolling into the fence of the field he was trying for.
Or, equally bad, he may overshoot. The distance was shorter than it
looked, he has more height to lose than he thought. He can gain
nothing by sticking the nose down, because in his plunge he gains
speed which will carry him too far on the ground. He may bowl over the
fence, or, if there is a field beyond, make the next field. More often
he finds himself in a patch of woods with a broken airplane.
It is possible that on a turn, a gliding turn with the engine shut
off, the pilot may lose his flying speed. Unless he is experienced, he
does not realize that on a turn the machine presents more surfaces to
the air and greatly increases the air resistance. It is likely to
stall unless a safe margin of speed is maintained. The dangerous part
of this is that very often the machine will lose its speed when only a
hundred feet from the ground, approaching the field. There is no
chance to pull it out of a spin unless the pilot is alert and realizes
that he has lost speed, and noses down before he spins. Often he
spins, and a fall with an airplane from a hundred feet is just as
nasty as it can be.
For his own safety in the air the civilian who is about to take up
instruction in flying should insist at his flying-school that he be
taught thoroughly, to his own satisfaction, the control of his machine
with the engine shut off for the moment. There is a certain feel, a
sing in the wires, he must know. He should continue at the work of
forced landings, going on his solo flights to various heights, pick
out his field, shut off the motor, and get down into that field--no
other. He should keep it up until he can make nine out of every ten
absolutely perfect, and the tenth one, though not perfect, still a
good landing.
Then it may be said that a pilot is safe. When he knows in his own
heart that nothing can happen to him which will throw him off his
guard, or which will worry him, he can take the air without fear.
V
QUALIFICATIONS OF AN AIRPLANE MECHANIC
What chance has a good automobile man who knows his engine thoroughly
to become an airplane mechanic? There can be only one answer to this
question which men ask themselves daily--there is every chance in the
world. Commercial flying, in the day when the air is to become a
medium of transportation, just as ground and water are at present,
must draw to itself hundreds of thousands of mechanics. The only thing
to which the future of flying may be compared is the automobile
industry at present. And the only place from which the mechanics are
to be recruited are from the men who are working in garages putting
automobiles in order.
An interesting comparison between the future for the automobile
mechanic or airplane mechanic compared with the future for the pilot
is afforded in the figures of a well-known flying-officer of great
vision. He expects that the skilled mechanic, the man who has spent
years at his trade, will command more for his services than a pilot.
Any one can learn to fly an airplane in one or two months of proper
training. A mechanic may work for years to learn his profession.
It was estimated that it took ten mechanics of various kinds on the
ground to keep one airplane pilot flying in the air, and the
experience of the United States has shown that there must be a large
force of trained men to keep up flying. The present leaders of the
automobile world and the aeronautical world are men who got their
first interest in mechanics in some little shop. Glenn H. Curtiss and
Harry G. Hawker, the Australian pilot, both owned little
bicycle-repair shops before they saw their opportunity in flying.
Most essential of all, for the man who would become an airplane
mechanic, is a thorough knowledge of gasolene-engines. This should
include not only a knowledge of such fundamentals as the theory of the
internal-combustion engine, carburetion, compression, ignition, and
explosion, but also a keen insight into the whims of the human, and
terribly inhuman, thing--the gasolene-motor. Nothing can be sweeter
when it is sweet, and nothing more devilish when it is cranky, than an
airplane engine.
There are certain technical details which distinguish an airplane
motor from an automobile motor, but a man who knows automobile engines
can master the airplane motor in short order. Generally speaking, the
airplane motor differs from the automobile motor in shape. The Liberty
type of engine is V-shaped, with both sets of cylinders driving toward
a common center, the crankshaft. Most airplane motors have special
carbureters, and their oiling systems are extremely finely adjusted to
take up any friction at their high speed. They will be found to be
lighter in weight, with pistons, piston heads and other parts made of
aluminium. They are, as a rule, more carefully made than most
automobile motors, with especial attention to the fitting of all
working parts.
One advantage which an airplane mechanic has is standardization, which
has reached a high point with Liberty, Hispano-Suiza, and Curtiss
engines. Once a mechanic has learned his type he has learned
practically every engine of that type. For a long time to come the
18,000 Liberty engines which this country had at the time the
armistice was signed will be carrying commercial airplanes across
broad stretches of the United States. If it had not been for the
pressure of the war this engine might have been developed slowly, as
the automobile engines were, with changes from year to year. The
Liberty engine has reached a high standard of efficiency, and is
likely to be the standard airplane engine in this country for several
years to come. An airplane mechanic who knows his Liberty engine will
be able to look after most of the airplanes with which he will come
into contact.
An engine which was not developed to the same high point in this
country as the Liberty motor is the rotary engine, of which the Gnome
Monosoupape or Clerget are perhaps the best-known types. These were
favorites with airmen flying fighting scout-planes. They weighed
practically nothing, for an engine. A one-hundred-horse-power motor
weighed only two hundred and sixty pounds, and it was a splendid type
for fast work. Briefly, the power generated by the explosions in the
cylinders, operating against two centers of pressure, gave a rotary
motion to the cylinders and crankcase, revolving around a stationary,
hollow crankshaft. Cylinders and crankcase were bolted together, and
the cylinders looked like the blades of an electric fan. There was
always an odd number of cylinders, so that there would be no
dead-centers, no point at which two opposing strains would be
balanced, causing the engine to stop. The propeller was bolted on a
nose cap which revolved with the engine. This type of engine is not
likely to be used to any extent for commercial flying, or even flying
for sport. It is expensive, very wasteful of gasolene and oil, and
difficult to keep in repair.
For men who may have had some experience in the assembly of airplanes
at factories, or of rigging them at flying-fields, there is great
opportunity. Expert riggers who know their craft are few and hard to
get. They are invaluable for maintaining a machine in flying
condition. The use of airplanes in this country will require men for
rigging, for truing up the wires and struts. Each airplane must be
overhauled after a few hours of flight to discover hidden weaknesses
and to tighten sagging wires.
Rigging an airplane has some resemblance to rigging a ship for
sailing. The first requisite is to see that the machine is properly
balanced in flying position. There is a number of minute measurements
which come with the blue-print of every machine and which must be
followed out to the letter to get the most successful results. An
important detail is the pitch of the planes, or the angle of
incidence, as it is called. This is the angle which a plane makes with
the air in the direction of its motion. Too great a pitch will slow up
the machine by offering too great a resistance to the air; too small
an angle will not generate enough lift. The tail plane must be
attached with special care for its position. Its angle of incidence
must exactly balance the plane, and it must be bolted on so that there
is no chance of it cracking off under strain.
Radio operators will be in great demand for flying. Brig.-Gen. A.C.
Critchley, the youngest general officer in the British service, who
was a pilot in the Royal Air Force, said that the future development
of the airplane must go hand in hand with the development of wireless
communication. He added that the most difficult thing about flying,
especially ocean flying, was to keep the course in heavy weather.
There are no factors which will help a man on "dead" reckoning; and a
shift in wind, unknown to the navigator of a plane, will carry him
hundreds of miles from his objective. The wireless telephone was used
to some extent during the war for communication between the ground and
the air; it will be used to a greater extent in the next few years.
Another development which is being used by the navigators flying the
Atlantic is the radio compass. This instrument may be turned toward a
land or sea wireless station, of which the call is known, and it will
register the bearing from the flying-boat to this station. It may be
turned upon another station, and this bearing also charted. The
intersection of these two wireless compass bearings gives the position
of the ship at sea. The radio compass is dependable day or night, and
is said to be quite as reliable as a sextant or other navigating
instruments.
Sailmakers to repair airplane fabrics, to sew new covers for
planes--these men must find an opportunity in flying. There are
literally thousands of wings, as yet unmade, which will carry the air
traffic of the future. It matters not whether men or women take up
this branch of the work, it must be done, and done with a conscience.
Like all other branches of the mechanical maintenance of an airplane,
careless work on the part of a sailmaker may mean disaster for the
pilot. One of the latest fatalities at a Long Island flying-field was
due to careless stitching, or weakness of fabric, which gave way under
great pressure due to high speed. The linen cover of an upper plane
ripped off at a height of one hundred and fifty feet, and the pilot
was killed in the fall of the machine.
Photographers may yet take the place of surveyors, or work hand in
hand with them in the making of aerial maps of the country. The map of
the future must be an aerial map, a mosaic map such as was used by our
army headquarters. Nothing can exceed the eye of the camera for
accuracy. Cameras bolted to airplanes, such as were used by our army
for reconnaissance, have already been used for mapping cities. The
mapping of the entire country in such a manner is only a matter of
time.
One thing which an aviation mechanic of any sort must bear in mind is
that he _must_ do his work with a conscience. True, he is handling
mute metal engines, or dumb wires and struts--but in his work he holds
the life of the pilot in his hand. It is not too much to say that
hundreds of pilots' lives have been saved by the conscientious work of
skilled mechanics who realized the danger of the air.
I have seen mechanics rush from a hangar in a frenzy of excitement
and agitation. "That machine must not go up; it has been repaired, but
not inspected!" They have done their work with a will in the army;
they have learned some of the dangers of flying and weak spots which
must be watched. The civilian mechanic must be taught many things.
First of all he must know the value of inspection. Every machine which
has gone through a workshop must be inspected and checked over by a
skilled mechanic before a pilot is allowed to fly it. The ideal thing
would be to have legislation licensing the inspectors of aircraft and
requiring that repairs on all machines be examined by a licensed
inspector. The inspectors would be under civil service and would be
selected by competitive examination. It may sound fantastic, but such
precautions are as necessary for the preservation of life as
legislation on sanitary matters.