I have spoken, in describing the fixed-wing versus moving-wing battle,
only of short air-lines, because I think the establishment of the
successful short line will precede the establishment of the long.
It is argued that the saving in time effected by the flying-machine
becomes valuable only in long journeys, so that no one would bother
to go to an aerodrome and take an aeroplane in order to save half an
hour or so, and that the train-service in England is so good that the
aeroplane-service would be incapable of competing with it successfully.
And, while the disadvantages of short air-services are magnified, the
disadvantages of long air-services are forgotten or not appreciated.
At present a short journey of three or four hours by aeroplane is all
that the average passenger can stand in comfort. There is no room for
him to move about much in the present cabins, and the noise of the
engines, wires, and airscrews is fatiguing to anyone not used to it.
Moreover, the time-basis is not the only basis on which the traveller
compares the merits of the means of travel at his disposal. The ship
provides its passengers with social intercourse and a high degree of
comfort. A long journey by sea is usually a pleasant, invigorating
experience. On a journey by air, on the other hand, the passengers
get no fresh air, they have no opportunity for making friends,
for conversation, dancing, games, or any other of the fascinating
trivialities which flavour life on board a passenger-steamer. The
traveller offered the use of a long distance air-line, therefore, is
invited to choose between, perhaps, three days discomfort and isolation
in the cramped cabin of an aeroplane and three weeks social pleasure
and invigorating laziness on board ship.
Now the disadvantages which attend long-distance air-travel in modern
type machines are due almost entirely to the small size of passenger
aircraft when compared with ships. The aeroplane will not be successful
as a long-distance vehicle until it can give its passengers most of the
pleasures they would get on board ship. It will not be able to give
its passengers even a small fraction of those pleasures until it is as
large as or nearly as large as the ship.
The pleasures of long-distance travel vary almost directly as the
size of the vehicle. Can the aeroplane ever be made so large that it
can offer its passengers the space and freedom of even a small-sized
passenger-boat?
I do not think the aeroplane can ever become sufficiently big, but I do
think the seaplane or the flying-boat can and will become sufficiently
big to offer that degree of space and freedom.
I believe that aircraft will begin to compete successfully with boat
and train in carrying the merchandize and passengers of the world only
after the coming of the era of the hydro-aeroplane (I use this word to
include both seaplane and flying-boat).
The longest flight ever made in one machine was made in a
hydro-aeroplane. The largest machines ever built are hydro-aeroplanes.
The heavier-than-air machines carrying the greatest weight are
hydro-aeroplanes. I am confident that the era of the hydro-aeroplane
will come, and that, until it comes, aircraft will not compete
successfully with boat and train.
I have based my first conclusion, that the moving-wing aeroplane
will become a powerful competitor of the fixed-wing aeroplane for
short-distance air-transport, on flexibility. The moving-wing machine
can go from door to door, no matter if the journey is partly over the
sea and partly over the land. I base my second conclusion, that the
hydro-aeroplane will become the pre-eminent vehicle for long-distance
air-transport, on size. The hydro-aeroplane can be built as large as
may be required.
If people are to journey even for one day in the same vehicle, they
need space and freedom of movement. They need wide promenade decks,
lounges, restaurants, cabins, smoking-rooms. They cannot be confined to
a single basket chair.
For long-distance air-transport the sardine-theory so popular with our
London transport controllers must be abandoned. The sardine-theory must
be recognized for what it is, a system of getting more money out of
the passenger by increasing his discomfort. The more you squeeze the
passenger, the more the money oozes out of him.
The aeroplane cannot, I think, become very much larger than the largest
machines of to-day because the support of much greater weights on the
landing-wheels becomes difficult. At present there are machines in
which each landing-wheel must carry 6 tons. If the weight were much
increased, the three-point suspension on wheels and tail-skid would
become impracticable. The provision of a caterpillar landing-gear and
of aerodromes with prepared surfaces might be possible and might assist
matters if machines, say eight or nine times the size of the present,
were contemplated. But, to obtain the comfort required (and given by
the ship) on a long voyage, the machines would need to be some fifty
or a hundred times the size of the largest existing types. When those
sizes were reached, the problems of supporting the weight on the ground
and of manoeuvring on the ground, taking off, and landing would become
exceedingly difficult to solve.
Yet these problems are comparatively easy to solve in the large
hydro-aeroplane. A large hydro-aeroplane with a high wing-loading
could, if necessary, use the open sea as its aerodrome. Since the
problem of the forced landing would definitely have been overcome by
the power-unit arrangement, the large hydro-aeroplane would fly over
land or sea. Its stations would be sea ports, lakes, or wide rivers.
The aeroplane both with moving and fixed wing will certainly grow
in size; but nothing seems to me to indicate that it will be able
to keep pace with the growth of the hydro-aeroplane. The growth
of the hydro-aeroplane is foreshadowed in a French machine and a
German machine which have appeared recently. The hundred-passenger
hydro-aeroplane is a proven possibility. I can see no insuperable
obstacle to the eventual arrival of the 1,000-passenger or the
2,000-passenger hydro-aeroplane. Moreover, the fog-landing problem
is easier to solve in the sea-going than in the land-going fixed-wing
aircraft. Good automatic landing devices are more easily designed for
hydro-aeroplanes than for aeroplanes.
Mr O. E. Simmonds, of the design staff of a firm of British flying-boat
constructors, said: “The largest successful flying-boats yet built have
weighed about 30,000 lbs. I shall certainly feel that progress has been
inordinately slow if we have not constructed a boat of 100,000 lbs.
gross weight _by the end of the next decade_.”
The first real air-liner, carrying some five or six hundred passengers,
will probably appear after or towards the end of the battle between
fixed and moving-wing machines. And it will be a flying-boat. The
unsolved problems attending high-altitude air-transport seem to be so
difficult that I am inclined to believe that high altitude transport
will not become a regular method in this generation.
The possibilities of machines capable of travelling at immense speeds
in the rarefied air at a height of 15 miles or so from the ground are
attractive. But, if a forecast is to be based on research-work actually
accomplished at the time, it is made, then high-altitude flying must be
excluded.
Among the problems which high-altitude flying involves and which seem
to postpone its arrival to the distant future are: the infinitely
variable pitch airscrew, the light, positive, infinitely variable gear
(without ratchet final drive), the sealed cabin with self-contained
ventilating system, the engine altitude supercharger, and the variable
camber-wing. Among these the Leitner automatic infinitely variable
pitch airscrew is one of the most interesting inventions ever made
in airscrew design, but it is at present in its earliest stages. The
Constantinesco torque-converter, which is an automatic infinitely
variable gear, might be adaptable to aircraft. The sealed cabin
presents great practical difficulties, as does the variable camber-wing.
From this brief parenthesis the difficulties of high-altitude
transport will be apparent. It is almost certain to come, but its day
is likely to be distant, and for that reason I have concentrated on
possibilities less remote.
Now that the long and short distance air-liners have been dealt with, I
will give a brief sketch of how the traveller will use these vehicles.
If Mr X, who lives at Hampstead, desires to go to Melbourne, Australia,
he will first pile his luggage onto a taxi and drive to the terminus
of some moving-wing aircraft line. This terminus will be close to the
centre of London: A highly developed moving-wing aircraft will take him
to the coast. The machine will land on the quay beside which will float
a flying-boat express. This machine will be a fixed-wing flying-boat of
about 1,000 tons. It will be a monoplane, the wings growing from the
hull at a sharp dihedral angle and then curving down until they are
horizontal.
The engines will be particularly interesting. Most designers, even now,
are endeavouring to eliminate reciprocating motion in petrol-engines.
The trend of thought is towards substituting the sleeve-valve for the
poppet-valve and towards increasing the number of cylinders. More and
more inventors “invent” gas-turbines. Their engines have had varying
degrees of failure, although a few, the Jean Mély turbine among
them, are reported to have gained a measure of success. One of these
inventors will soon be completely successful. The movement towards the
rotary gas-engine is too vigorous and too general to remain for ever
unfruitful. The gas-turbine will be the aero-engine of the future. It
will be cooled by an evaporative system.
One pound of water carries only 20 B.T.U., whereas 1 lb. of steam
carries 966 B.T.U. Wing Commander Cave-Browne-Cave, in a paper read
before the Royal Aeronautical Society, drew attention to the advantages
for aircraft of evaporative engine cooling. He said: “By far the
lightest way of conveying heat is as the latent heat of steam.” On test
a standard aero-engine gave the same power and fuel-consumption with
evaporative as with water-cooling. The greatest advantage will accrue
in reduction of resistance. Panels in the aircraft surface will receive
heat in the steam and thus the drag caused by water-radiators even of
the wing or strut type, or air-cooled cylinders will be eliminated.
The evaporative cooling system will not freeze up at the highest
altitudes: it will probably maintain the engine at a more even working
temperature than an air-cooling system, and the steam will provide a
suitable means of heating the passenger cabins and pilot’s cockpit and
of cooking.
The flying-boat to which Mr X is now having his luggage transferred
then, has twelve evaporative-cooled gas-turbines housed in the
wings, six on the starboard and six on the port side. Eight of them
will drive tractor airscrews and four will drive propellers through
torque-converters. There may be a system of concentrating the whole
engine-power at three or four airscrews.
The entire machine, including the wing-coverings, will be built of
metal. “I cannot conceive”, said M. Dewoitine, the French designer,
“that the ultimate aeroplane can be in anything else but metal, in the
same way that metal ships to-day completely replace the wooden ships
of days gone by.” The living quarters in the hull would be arranged
on labour-saving lines. The passengers would have drawing-room,
dining-saloon, lounge, and promenade deck. The promenade deck on a
long-distance air-express will be different from the promenade deck
on a liner. It will be enclosed in the hull and will be lighted by a
transparent roof and sides.
Mr X finds his cabin arranged in much the same way as in a ship, and,
having settled his things, he goes up to the lounge, where the other
passengers are congregating. A few minutes later, with a faint hum, two
of the tractor-airscrews begin to revolve, and the flying-boat moves
slowly away from the quay. Two more airscrews start revolving, and the
machine, having taxied out, turns into wind. It pauses a moment as
if it were taking breath, then the twelve air-screws spin faster and
faster until they appear as discs of light. The machine moves forward
heavily, a solid mass of metal, with the passengers watching from the
windows of the promenade deck. It lumbers through the water, but throws
up but little spray. Then it seems to stretch itself, throw back its
head, and to rise bodily out of the water until it runs on the surface
of—instead of in—the water. Already it appears lighter and less clumsy.
Finally, after giving the water two or three parting pats, it takes to
the air and, in spite of its great mass, instantly becomes an agile,
graceful flying-machine.
The usual amusements, the usual eating, drinking, reading, and talking
will employ the passengers’ time in the air. For the daily round goes
on in much the same way ashore, afloat or aflight. The night flying is
exhilarating, although there is, of course, almost no sense of speed.
Though the sea is rough, the machine, at 4,000 ft. is as steady as a
rock. As the first stopping place rushes towards the machine, the hum
of the engines alters note and the machine dips in a gentle glide.
The mouth of a river, with shipping on it and two more flying-boat
expresses lying at a quay a short way up the river, comes into view.
The machine wheels round and glides closer and closer to the water.
Four of the airscrews give a short burst of speed, and then the hull
rips the surface of the water with a hiss.
Soon afterwards Mr X has said good-bye to his voyage acquaintances who
are disembarking, and the machine is off on the next stage.
The success of the large, long-distance flying-boat will mark the
beginning of the concentration of fixed-wing machines on long-distance
routes and the concentration of moving-wing machines on short, distance
routes. The fixed-wing machine, finding it has no rival in the large
flying-boat type and finding that it has a strong rival in the
comparatively small land-going type (that rival being the moving-wing
machine) will gradually remove itself from the short air-lines. The
position will then be that all short air-lines are run by moving-wing
land-going aircraft while all long air-lines are run by fixed-wing
sea-going aircraft.
The real air-liner, as distinct from the commercial flying soap-box
of to-day, will be an immense sea-going air-vessel. It will be a
self-contained town offering greater attractions to the pleasure-seeker
than any other kind of small town. When that machine makes its
appearance the Air Age will have begun.
V
Before I described the passenger-carrying flying-machine towards which
contemporary research-work seems directed, I postulated the freedom
of the air for that machine. I stipulated that the statesman and the
financier should be gagged and bound. Now that I come to private-flying
and air-racing, however, the imagination jibs at the notion of a
similar freedom of the air. If the statesman were prevented from
meddling with the technical development of the passenger-carrying
flying-machine, he would most likely turn with redoubled vigour to
the task of controlling, organizing, watching over, regulating, and
generally bleeding the private, the record-breaking, and the racing
aircraft.
I can, therefore, sketch the future of those machines only as the
statesman will direct it.
The small fixed-wing private flying-machine, especially in the
amphibian form, will gradually become more and more popular and, as it
grows more popular, so the statesman will take more notice of it. His
first opportunity for direct action will come when a few people get
killed in an accident involving a private aircraft.
Taking advantage of the Press outcry, of the screams of the Safety
First societies and of the opportunity for personal aggrandizement,
Members of Parliament will pass a Flying-Machine Act.
Among the provisions of this Act will be a 40-miles per hour minimum
speed-limit. No heavier-than-air craft will be permitted to fly at a
speed of less than 40 miles per hour. It is easy to follow the workings
of the official mind in setting this speed-limit. A fixed-wing aircraft
crashes not because it goes too fast but because it goes too slowly.
Therefore, the statesman will reason, if it is illegal to go too
slowly, there will be no more accidents.
Another provision will make it illegal for anyone suffering from
nicotine-poisoning to be in charge of a flying-machine. (Prohibition
will be established in England by this time, so that no clause about
“drunk in charge of a flying-machine” will be necessary.)
Further regulations will make it necessary for every private pilot to
pass a medical examination once a month as a condition of his having a
pilot’s licence. Having passed this examination, he will be required
to wear, while in charge of an aeroplane, two 8-inch metal discs, with
a number stamped upon them. One disc will be worn on the left shoulder
and the other on the top of the flying-helmet.
The aeroplane, in addition to its letter markings on wings and
fuselage, will be required to exhibit three plaques bearing
identification-numbers. One will be on the centre section, one on the
undercarriage, and one on the port side of the fuselage. The aeroplane
will also carry metropolitan or county police markings on four tablets
of given size, besides markings of the appropriate local council on
plates of certain specified dimensions, and small circular pieces of
paper contained in approved holders on the rear port interplane-strut
(or wing-tip in the case of a monoplane), the rear starboard
interplane-strut (or wing-tip) the undercarriage port forward-strut,
the tail-fin, the fuselage, and the top plane gravity-tank (if any).
In addition to the pilot’s logbook, machine logbook, engine logbook,
pilot’s licence, and airworthiness certificate, there will be a
registration-book, travel-triptych, flight-permit, landing-permit, and
housing-pass.
These items are, of course, extra to the navigation-lights, wing-tip
flares, cockpit-illuminants, parachute-flares, fire-extinguishers,
silencers, life-saving parachutes, and other obligatory equipment, such
as lifebelts, fire-proof bulkheads, stall-indicators, warning-signals,
and Very lights.
These regulations will provide the police with the opportunity of
displaying their keen sense of duty. They will ignore the old-fashioned
and mundane murders, and will say with Horace Walpole: “Do not wonder
that we do not entirely attend to the things of earth; fashion has
ascended to a higher element.”
Conceive the vigour and elegance with which they will uphold the 40
m.p.h. minimum speed-limit. What their stopwatches (for they will still
use them) and observation lacks in accuracy, they will make up for by
the free imagery and sweeping poetic fancy of their evidence in Court.
The pilot who flies while suffering from nicotine-poisoning will be
the object of universal opprobrium. His social doom will be sealed
when the witness says that his breath _smelt of tobacco_ and that he
must have been smoking the same morning. The pilot’s statement that he
only had two cigarettes during the previous month will be completely
discountenanced.
But the best chance for the police will come when the private
moving-wing machine begins to make an appearance. Then will dawn the
true constabulary millennium.
The moving-wing machine, as it has been shown, can almost hover and can
fly comfortably at five or ten miles per hour. One day a moving-wing
machine will pass through a police-trap while its pilot is admiring the
countryside or inquiring from his companion where they will stop for
lunch.
The pilot will appear in Court charged with flying at less than 40
miles per hour, and there will be a sensation when the detectives
disclose that defendant’s speed, which he did not deny, was 8 miles per
hour over a measured furlong.
The magistrate will say that, although he had been on that bench for
thirty-five years, never in his whole experience, never from the
moment that he had accepted those duties, never since the time when he
devoted himself to the administration of justice, _never_ had he heard
of such a flagrant disregard for the safety of the public. Here was a
flying-machine, over a populous area, travelling at 8 miles per hour
when everyone knew that a flying-machine gained its lift by virtue of
its speed through the air, and that if it travelled at less than forty
miles per hour it was liable at any moment to fall upon the heads of
the people below.
The pilot might endeavour to explain the technical points in the case.
If he did so, his fine would be greater than if he merely pleaded
guilty and said no more.
That case will be the signal for a wholesale persecution of moving-wing
aircraft-owners. The Home Secretary will issue warnings, magistrates
will wish that they could send pilots to prison—in fact there will be
the usual process of departmental browbeating which we know so well.
The theory that the private flyer will not be summoned for slow flying
because there will be moving-wing passenger aircraft also capable
of slow flying, does not bear investigation. There are now lorries,
motor-buses, charabancs, steam-wagons, and trams which persistently
exceed the 20-miles per hour speed limit. They are not prosecuted, nor
will the passenger aircraft of the future be prosecuted.
Having given some idea of the delightful future which lies before the
private flyer, I will add a few remarks upon air-racing.
After motor-road racing, air-racing is the finest sport yet invented. I
give it ten more years life in England.
Before the War air-racing at Hendon was highly successful in that it
attracted many entries and large crowds of spectators. Since the War
air-racing has been unsuccessful. There are signs, however, that there
will soon be a revival of it. Larger and larger crowds will collect to
watch it. Special machines will be constructed, the number of entries
will increase, continental firms will take part.
Then the statesman will step in and play his part, as he always must
when anything becomes popular.
Air-racing is and will remain dangerous. Statesmen and newspapers
will discover this and talk about it. Now I am informed upon the best
authority that in England no one is allowed to face danger of any
kind, whether he wants to or not. The State arranges that all dangers,
physical and moral, are kept away from the individual. He may not do,
see, hear smell, or taste anything calculated to arouse him from
the suety state of mind so highly esteemed by the politician. The
Englishman is nursed from birth to death by an army of officials. He is
permitted to risk his life only in war.
Air-racing, since it is dangerous, will gradually be stamped out of
existence. Air-racing improves the aircraft as a machine-entity; it
would have a good effect upon the private flyer’s machine and upon the
war-machine. When air-racing has been stopped, therefore, a decline in
the quality of the private flying-machine and the service-machine will
result.
Air-racing (with which I include record-breaking) is as important to
pure aeronautical development as anything else. The history of the
Schneider Cup seaplane-race is some indication of the technical advance
racing achieves. In 1913 at Monaco the Schnieder Cup, was won by France
at 45.4 m.p.h. In 1914 (England) at 86.4 m.p.h., in 1919 (Italy) at
124.9 m.p.h. (This race was declared void). In 1920 (Italy) at 107.2
m.p.h. In 1921 (Italy) at 111.4 m.p.h., in 1922 (England) at 146.1
m.p.h., in 1923 (America) 177.4 m.p.h., in 1925 (America) 234.4 m.p.h.
and in 1926 (Italy) at 246.5 m.p.h. (Fig. 3).
[Illustration: _Fig. 3 Schneider Cup_]
The Schneider Cup figures show that the much boasted rapidity of
progress in the performance of high-speed aircraft during the War
is a myth. During the War, progress was almost completely stopped.
Even if the Italian win of 1919 at 124.9 m.p.h. be accepted (and the
race was declared void because Janello was not observed at one of the
turning-points) the rate of progress compares unfavourably with the
rates before and after the War. If, on the other hand, the rate be
judged by the accepted wins of 1914 and 1920 then the top speed of
seaplanes rose only 20.8 m.p.h. in 6 years against 139.3 m.p.h. in 6
years after the War.
Up to 1926 there has been little sign of a falling off in the rate of
progress in high-speed seaplane-design, and a rough estimate, puts the
probable speed of the winner in 1928 at 290 m.p.h. and in 1930 at 320
m.p.h.
Record-breaking has a similar effect to racing upon technical
development. In 1919 Sir John Alcock and Sir A. Whitten Brown flew the
Atlantic non-stop for the first time in a heavier-than-air machine.
They covered 1,890 miles in about 16 hours. In 1926 M. Dieudonné Coste
and Capitaine Rignot covered 3,400 miles non-stop in 32 hours.
Whatever country takes up and encourages private flying, air-racing
and record-breaking will play a big part in the future of the
flying-machine.