Chapter 5
The primary conditions of flight are that lift made by the planes shall be equal to the force of gravity, and that the forward thrust must be equal to the drift. At that point a machine will sustain flight--a fairly simple thing on paper. But the times that machines have stalled in the air, with their motors full on because their pilots have failed to sustain flight, have let the force of gravity overcome lift, are too numerous to mention.
That dart, if pointed at a proper angle and let loose, will fly; its lift will overcome the force of gravity, even though it has no motive power of its own. An airplane without an engine could be pushed off the Palisades at flying speed, and a skilful pilot could bring it to a reasonably safe landing at the foot. Flight does depend on motion, but motion does not depend on motive power. Given a sufficiently high altitude, the mere act of dropping through the air creates motion, and this motion will sustain flight.
An airplane is in no particular danger in the air if the motor stops--provided it is in an open stretch of country with plenty of fields. Instinctively the pilot will nose down and glide, and on that glide he will find himself maintaining flying speed. He can turn and maneuver his machine, and pick out almost any field near at hand. The only limitations are that he cannot glide more than five times his height, and when he comes down to the ground he must stop gliding and land. He must land on anything that presents itself, a field if he has good judgment; if not, then a barn or swamp or woods. He must land when the end of his glide brings him to the ground.
This is commonly termed a "forced landing," and in every sense of the word it is one. There is no pilot of any extensive flying experience who has not had to make a forced landing. Ninety out of a hundred are perfectly orderly safe landings; the odd ones are occasionally crashes. Incidentally it may be said that forced-landing practice by flying pupils is the most beneficial which may be imagined. It teaches control over a machine as nothing else will. It may be carried out from any height, shutting off the motor, picking out a field, gliding for it, turning and twisting to get into proper position as regards the wind, and "giving her the gun" just at the fence and flying on.
A forced landing over the country is safe, but over a city it is the most deadly thing imaginable. For a machine caught with a "dud" engine over New York there is no escape but a terrific crash in the city streets, against the side of some building, with danger to the pilot and the people in the street below. There has been no motor made by the hand of man which would not let a pilot down at some unexpected time. The instance of Major Woods, starting on his flight across the Atlantic, and forced to come down to the Irish Sea is one example. The NC-4, American naval seaplane, had a forced landing at sea, a hundred miles from Chatham, Massachusetts, on the first leg of the Atlantic flight from this side. Its engines had been carefully cleaned and tested, and yet they failed. Harry G. Hawker's engine failed him half-way from Newfoundland to Ireland and let him down into the sea, from which he was picked up by the greatest good luck.
That is one of the most exasperating and human things about a gasolene-engine. It is efficient, but not thoroughly dependable. The best of them are liable to break down at the most needed moment, due to a hundred causes outside of the control of a mechanic or pilot. Care and rigid inspection will reduce the possibilities, but engine failure cannot yet be eliminated.
That is one of the principal reasons why the roofs of buildings around big cities are so dangerous. The sides of a building drop away from the roof. An error in judgment and the machine is over the edge.
It is even more dangerous to take-off. An airplane motor is ten times as likely to develop a weakness while it is cold. A motor starting a flight is never well warmed up, and fifty feet from the edge of the roof it may give out, with awful consequences. As a practicable thing, roofs are at present impossible. There is not a flying-officer in the world who will not agree.
An interesting series of experiments has been carried out in England on what has been known as the helicopter machine. This machine is not dependent upon speed to fly, but merely on engine power applied through a propeller of great pitch. The idea is not new, but is along the lines specified by Orville Wright when he said that a kitchen table could fly if it had a good enough engine.
The effort is being made to make a machine which can hover, can hold itself in the air by brute force of its propeller blades beating the air. The thing sounds impossible to adapt, say some aeronautical engineers. Those who have seen the experiments, however, express great optimism.
A machine of this sort would land and take-off in a very small space, and might be adapted to use around cities. It might even make flying over cities safe but for the human equation of the engine again. This machine is dependent on engine power. Apparently there would be two engines, or two driving mechanisms, one operating the lifting propeller and the other the pulling propeller.
For the present the great need is for landing-fields as near the heart of most American cities as possible. There should be quick transportation to the business section provided, as well as hangars and mechanics. When that is done we may very well say that aerial transportation for passengers and freight is an accomplished fact.
VIII
THE AIRPLANE'S BROTHER
At the end of 108 hours and 12 minutes of sustained flight, more than four days, the British dirigible R-34 swung into Roosevelt Field, came to anchor, and finished the first flight of the Atlantic by a lighter-than-air airship. To the wondering throngs which went down Long Island to see her huge gray bulk swinging lazily in the wind, with men clinging in bunches, like centipedes, to her anchor ropes, and her red, white, and blue-tipped rudder turning idly, she was more than a great big balloon, but a forerunner of times to come. She had come to us, a pioneer over the sea lanes which are to be thronged with the swift dirigibles of the future plying their easy way from America to Europe.
The performance of the R-34, undertaken in the line of duty, has eclipsed all the previous records made by dirigibles and is, in fact, a promise of bigger things to come. There was that Zeppelin, which cruised for four days and nights down into German East Africa and out again, carrying twenty-five tons of ammunition and medicine for the Germans who were surrounded and obliged to surrender before help arrived.
The R-34 started from East Fortune, Scotland, on Wednesday, July 2, 1919, at 2.48 o'clock in the morning, British summer time, and arrived, after an adventurous voyage, at Mineola, Sunday, July 6, at 9.54 A.M., American summer time. She had clear sailing until she hit the lower part of Nova Scotia on Saturday. Electrical storms, which the dirigible rode out, and also heavy head winds, kept her from making any progress, and used up the gasolene. About noon of Saturday the gasolene situation became acute, and Major G.H. Scott, her commander, sent a wireless message to the United States Navy Department at Washington, asking for destroyers to stand by in the Bay of Fundy in case the gasolene should run short and the airship get out of control. Destroyers were immediately despatched, but in the next few hours the weather improved, and the ship was able to continue on her journey. It was feared, however, she might run out of fuel before reaching Long Island, and mechanics were sent to Chatham and to Boston to pick her up in case of trouble.
The big ship surprised everybody by appearing over Long Island about nine o'clock Sunday morning. The officer in charge of the landing party having gone to Boston, expecting her arrival there, Major John Pritchard "stepped down" in a parachute from the airship, and, landing lightly, took charge of the landing of the big machine.
An approaching cyclone, which would have made it almost impossible to handle the airship at Mineola, was responsible for a rather hurried start back at midnight of Wednesday, July 9th. She visited Broadway in the midst of the midnight glare, turned over Forty-second Street a little after one o'clock in the morning, and put out to sea and her home airdrome. The voyage back was mostly with favoring winds, and she landed at Pulham, the airship station in Norfolk, after 75 hours and 3 minutes of flight. The voyage back was practically without incident except for the failure of one engine, which in no way held back the airship. She was turned off her course to East Fortune by reports that there were storms and head winds which might hold her back in case she kept on her way.
The voyage was probably the most significant in the history of flying. It brought home to the public the possibilities of the airship for ocean commerce as nothing else could have done. The ship remained in the air longer than any previous airship, and pointed the way clear to commercial flying. It is, in fact, only considered a matter of time before companies are started to carry passengers and mails across the Atlantic at a price that would offer serious competition to the fastest steamships.
The airship has been very much neglected by popular favor. Its physical clumsiness, its lack of sporting competition in comparison with the airplane which must fight to keep itself up in the air, its lack of romance as contrasted with that of the airplane in war, have all tended to cast somewhat of a shadow over the lighter-than-air vessel and cause the public to pass it by without interest. It is a very real fact, therefore, that very few people realize either the services of the airship in the war or its possibilities for the future.
During the war the airship was invaluable in the ceaseless vigil for the submarine. England early stretched a cordon of airship guards all about her coasts and crippled the U-boats' work thereby. The airship had a greater range of vision and a better downward view than any sea-vessel; it could travel more slowly, watch more closely, stay out much longer, than any other vessel of the air. The British credit their airships with several successful attacks on submarines, but they give them a far greater place in causing a fear among the under-sea boats which drove them beneath the surface and greatly limited their efficiency.
The German Zeppelins, on the other hand, stand out in public imagination as a failure in the war, especially because the British shortly established an airplane barrage which proved to be their masters. This view is correct only in so far as it applies to interior raiding, for which, indeed, the Zeppelin was not designed. How untrue it is of the Zeppelin as the outpost for the German fleet British officers will readily admit. Indeed, they credit them with the escape of the German fleet at Jutland, one of the deepest regrets in British naval history. As eyes for the German fleet in the North Sea, the Zeppelins, with their great cruising range and power of endurance, proved almost invaluable.
Airships have, then, behind them a rich heritage and before them a bright future. Much work that the airplane can do they cannot do; while, on the other hand, much work that they can do the airplane cannot. The two services are essentially different and yet essentially complementary. Between them they offer nearly every facility and method of travel in the air which could be desired. Each must be equally developed in order to increase the efficiency and the value of the other.
The great difference, of course, between the airplane and the airship is that the former sustains itself as a heavier-than-air vessel by the lifting power of the air in relation to a body driven hard against it by its powerful engines, while the latter sustains itself as a lighter-than-air body because of the large amount of air displaced by a huge envelop loaded with gas much lighter than the air itself. The contrast is obvious; one vessel is small, agile, and very fast; the other is slow and clumsy. The airship cannot attain anything like the speed of the airplane, nor can it go so high or maneuver so quickly, but on the other hand, at least for the immediate present, it can stay afloat very much longer and carry much greater weight.
Moreover, the airship has certain other easily perceptible advantages over the airplane. Ordinarily an airship need not fly at much more than a thousand feet, which not only makes far less cold traveling than at higher altitudes, but also allows the passengers to enjoy the view far better than from an airplane, whence the world below looks like a dull contour map. An airship also flies on an even keel; it does not bank as an airplane does nor does it climb or descend so quickly.
At present airship travel gives a greater feeling of comfort and security. Sleeping is a calm experience; moving about comparatively simple. Also there is less noise than in an airplane where the engines beat incessantly and the wind rushes through the wires and struts. An airship has no wires and can at the same time slow down and even shut off its engine, so that it need be no more noisy than a motor-car. Engine failure also is not so serious as in an airplane, for the gas-bag will always keep the ship up until there has been a chance for repairs.
Up to the present, too, the airship is less of a fair-weather flier than the airplane. A surprising record has been attained in the war by British airships, as is shown by the fact that in 1918, a year of execrable weather, there where only nine days during which their vessels were not up. This is, of course, in considerable contrast to airplanes as at present developed, but it may reasonably be expected that the latter will very soon develop to the same point of independence of the weather.
Of course, the great difficulty of airships has been their ungainly size and the difficulty of housing them. The sheds, particularly those for the Zeppelins, have been most costly, but the British have recently developed a system of mooring masts which make much of this expense unnecessary. If such a device can be successfully put into every-day use it will enormously increase the ease of loading and unloading passengers, which now makes for considerable discomfort and loss of time.
Some of the plans for future airships are unbelievable to one who has not followed their development carefully. Already there is planned in England a monster ship known as the "ten million," for the reason that it will have a gas capacity of ten million cubic feet, over four times that of the largest Zeppelin. The length is placed at 1,100 feet, the speed at 95 miles an hour, the cruising range 20,000 miles, and the cost at about $1,000,000. As a matter of actual practice, however, the best division of the space and lifting power of this airship would be for it to carry a crew of about 20, a useful load of 200 passengers or 150 tons of merchandise, and 50 tons of petrol, which would give it a non-stop run of about 5,000 miles.
Airship travel would undoubtedly be expensive. The gas alone to maintain such a vessel as described is expected to cost about $30 an hour, which, added to the original investment for the ship and its house and the wages of the crew and the 200 or more skilled men at each station, would come up to a high figure. At the same time, the airship would not afford the element of very high speed which is so certain to justify any expense which may have to be put into the airplane. Nevertheless, with the improvements that are sure to come, with the ability to reach places not touched by other methods of travel, the freedom from all the delays, inconveniences, and expense of trans-shipment, this preliminary charge will be largely compensated for.
Those who sponsor the airship urge that it will be used almost exclusively for long-distance flights beyond the range of the ordinary airplane and very little for short local flights. For transatlantic travel, for instance, it is being particularly pressed, as ships even of to-day have all the capacity for such a voyage, without the dangers which might surround an airplane if its sustaining engine power were to give out.
There are several records which would easily justify it. Besides the flight across the Atlantic by the R-34 and the four-day trip of the German airship from Bulgaria to Africa and back, a British airship during the war stayed up for 50 hours and 55 minutes, and another, just after the armistice, stayed up for 61 hours. An American naval dirigible a short time after the armistice made a flight from New York to Key West, 1,200 miles, at 40 miles an hour, for 29-1/2 hours, with one stop at Hampton Roads. As an example of some of the difficulties of airship travel, this landing was possible only after the ship had circled the town and dropped a message asking the people to go to a large field near by and catch the dirigible drag-net when it approached the ground. Even at that, however, the time of less than a day and a quarter for what is usually a very arduous train trip from New York down the coast to Florida gives some indication of the possibilities of this method of travel when properly developed.
Practically all the new airships contemplated look to a much greater speed than the pre-war speed of about 40 miles an hour. It is not at all uncertain that they will not run up as high as 100 miles, though at the present time that figure is extreme. But granted that they no more than double the pre-war speed and reach the actual figure contemplated of about 75 miles an hour, they still would triple the best passenger-steamer speed, which would make them a matter of the utmost importance in all long ocean voyages.
Just how the balance will be struck between airplanes and airships is a big question. It is interesting to note, however, that the supporters of the airship have worked out a general theory that the lighter-than-air vessel with its already demonstrated cruising and weight-carrying capacity will be used for all long routes, and for that almost exclusively, while the heavier-than-air vessel, with its great speed and facility for maneuvering, will be used for local flights. This, in their viewpoint, would mean that the world would be girded by great lanes of airships, fed from a few main centers by swift-scurrying airplanes radiating in from every direction.
IX
THE CALL OF THE SKIES
The day of the air has undoubtedly come. The old order of the world has been entirely changed. A new life is breaking in over the near horizon. Almost in a moment the span of the world has shrunk to a quarter of its former size, so that where before we thought in terms of countries very soon we must think in terms of continents. The world is shortly to be linked up as it never has been before, till the great continents are brought as near as were the near-by nations of the past years.
Any one who doubts the future of aviation should realize the helplessness of the science after the armistice because of the complete lack of international laws to make possible its application in Europe, where it was most highly developed. With men and machines ready, they had to hold to the ground largely because there was in force no treaties assuring them the right to cross frontiers. The broad plans for international routes were held up because aviation itself was so big in its expanse that it could not meet its just fulfilment within national lines.
As a result a new law must be written. The law of the air will be one of the most intricate and the most fascinating in the world. It presents problems never before presented and covers a scope paralleled only by the laws of the sea. Very fortunately, however, aerial international law may be written at the very start of the science by a common international standard and practice, thus obviating the greatest part of the divergences which long years of habit have grafted into the maritime laws of the various nations. The slate is clean so that uniformity may be assured in a law which is soon to come into the most vital touch with the daily lives of the nations.
Who, for instance, owns the air above the various nations? Obviously the individual landowner has rights, especially as to freedom from damage. The nation also has rights, especially for its protection and for police work. How high, however, does this jurisdiction go? Some assert that a maximum altitude should be set, say five thousand feet, above which the air would be as free as the seas; others that each nation must have unqualified control to the limit of the ether.
Then comes the question of passports, customs, registration, safety precautions, and damages. As already shown, the man on the ground is helpless against the airplane which chooses to defy him. People and goods can cross national lines by the air without passports or customs. There will be no main ports of entry as in sea or train commerce, and it is too much to think that any nation can patrol its whole aerial frontier in all its various air strata. Undesirable immigrants or small precious freight can be smuggled in with the greatest ease through the route of the air.
Obviously the most elaborate international rules are necessary. Planes must have some method of international registration and license, just as in a more limited sense ships on the seas have what amounts to an international status. Landing-fields must be established and open to foreign planes, each nation providing some kind of reciprocal landing rights to other nations. Arrangements must be made so that if a monkey-wrench drops out of a plane a mile or two up in the air proper damages can be collected. For such things there is to-day but little precedent in law.
This but sketches the problems. It shows, however, how closely this new science will bind the world together and obliterate national lines and nationalistic feelings. As the sea has been the great civilizer of the past, so the air will be the great civilizer of the future. Through it men will be brought most intimately in touch with one another and forced to learn to live together as they have not been forced to live together before. The artificial barriers that have stood so firm between nations in the past are now swept away and a great common medium of intercommunication opened.
Let it not be understood that all this will take place overnight. Far from it, for the experience of the war has taught only too well that the organization of an air force takes time and patience. Up to date the essential fact is that the science, the value, and the possibilities of flight have been proved in a thousand different ways. Vistas of travel and experience have been opened up which but a few months ago would have seemed fanciful. Everywhere men are dreaming dreams of the future which challenge one's deepest imagination. Already Caproni, the great Italian inventor, has signed a contract to carry mails from Genoa to Rio Janeiro.
Now comes news of an airplane with room for ninety-two passengers. Engine power and wing space have gone on increasing in a dazzling way till one is almost afraid to guess what the future may hold. But, omitting all prophecy, the actual accomplishments to date are so stupendous that there is no need to speculate as to the future. If all technical development were to stop just where it stands, the factories and workshops of the world could well be occupied for years in turning out the machines necessary for the work awaiting them. Scientific development has gone so infinitely far ahead of actual production that as yet aviation is not being put to a fraction of its use.