Automobiles That Fly
I
ABOUT thirty-three years ago the Wright brothers solved the problem of flight in heavier-than-air machines. Ever since then crackpot inventors and imaginative writers have predicted, from time to time, that in a few years everybody would be flying in the same casual way we now use automobiles. Such glowing forecasts have proved erroneous, because no work has been done by trained scientists with adequate means for research until recent years.
There are now very definite reasons why such a prediction would be in order. As a matter of fact, it is likely that within ten years the solid citizen who buys an automobile will have the option of buying a ground gripper or one that can fly.
To explain the significance of modern design trends in the field of aircraft for the private owner, I must trace the development of aircraft in the past. There are reasons why all airplanes up to and including present conventional designs have not been adapted to widespread operation by private owners.
But here is something that should surprise you. The best airplanes in 1914 were easier to fly than the best commercially available to-day. They were not, however, safer to fly. Little was then known of aircraft structural engineering. The machines of that day were flimsy affairs and apt to fall apart in the air. They were so underpowered that the difference between their top speed and the minimum required to sustain flight was not much more than ten miles per hour. The stall was an ever-present menace, and this, with the tailspin which frequently follows it, remains to this day the bête noire of the novice pilot. Yet it is an aerial phenomenon about which little is known by the non-flier. The term ‘stall’ does not refer to the engine. The stall results from a loss of speed. It can happen with or without power.
Asking a question is possibly the best way to explain the stall. If a ton of miscellaneous junk is suspended two hundred feet in the air and suddenly cut loose, what will happen? The answer is obvious. The ton of junk will fall rapidly and heavily to the ground. But what will happen if an airplane and a ton of junk are both suspended two hundred feet in the air on separate cables and are cut loose simultaneously? It is probable that nine out of ten non-fliers can’t answer that one. The airplane will beat the ton of junk to the ground and will hit harder, because it will be going faster. The reason: an airplane is streamlined; junk is not.
The point I want to bring home is that an airplane does not fly by any process of magic; it is sustained because of natural laws. The chief essential is forward speed. An airplane must have a certain minimum forward speed any time it is in the air. If it does not, it is just a ton of streamlined machinery. The minimum velocity required to keep an airplane in the air depends upon the design of the individual ship. It varies from about thirty-five miles per hour to ninety or more for some racing planes.
The airplane can be controlled, and its weight is so distributed that it will fall nose first after it is stalled. As soon as its vertical descent is at a velocity which exceeds the minimum requirement for sustained flight, the pilot can ease back on the control stick and put his craft in level flight.
But it so happens that the stall is complicated by another aerodynamic phenomenon — the tailspin. If, when an airplane loses its flying speed and is thus stalled, any change is made in the direction of flight, either by the pilot operating the rudder control or by a gust of wind from the side, the plane is likely to fall into a spin. In beginning a spin, an airplane falls to one side for two or three hundred feet, the nose constantly dropping lower. This preliminary is known as ‘falling off.’ When the nose is well down, the ship starts spinning about an axis that approximates its longitudinal axis, though slightly to one side.
II
Flying is only thirty-three years old, but some fascinating legends have grown up about it. One of the most dramatic is the story of the first pilot who discovered how to bring his ship out of a spin. When the World War started, nobody knew the answer. One day an American pilot in the Lafayette Escadrille told his mates that he was sure he knew the way to recover from a spin. He proposed to bet his life that his theory was sound; he informed the squadron that he intended to put his ship in a deliberate spin and then bring it out. Everybody came to watch. He climbed his plane to five thousand feet and started a spin. His mates stood on the ground, craned their necks, and watched the ship as it fell earthward, its wings gyrating wildly. Cigarettes in their hands were forgotten; several suffered burned fingers. Then the little wartime craft suddenly ceased its wild spinning. It leveled off.
A few minutes later its pilot landed, rejoined the others, and told them that the way to recover from a spin was to push the stick ahead instead of holding it back to lift the nose. The name of this man even now is lost in the antiquity of the war. As a matter of fact, I suspect that several early-day pilots discovered the way to get out of spins at about the same time. But one must salute those early pilots who knew that spins could happen, did not know how to get out of them — and flew anyway.
The stall and tailspin are now thoroughly understood. Performed at safe altitudes where there is plenty of room to recover, they are among the simplest of manœuvres. But despite that fact they still take a heavy toll among novice pilots. Here is the reason: —
When an airplane is turned while in the stalled position, a spin is almost certain to result. Another aerodynamic law, combined with that fact, breeds treachery. An airplane in a turn stalls at a higher speed than one flying straight. So the pilot can go into a turn with just enough speed to maintain flight and control while flying straight, but stall when he gets into the turn because of higher speed required to support his ship while turning. As he is already in a turn, the requirement for a spin (a turn while stalled) is satisfied. The ship ‘falls off.’
Unfortunately accidental spins are far more likely to happen near the ground, where they are usually fatal, than at high altitudes, where they are harmless. An amateur flier, in making a forced landing, is likely to try to stretch his glide. If, in hunting a place to land, he turns while gliding with the nose too high (and his speed too low), his ship may suddenly ‘fall off’ with very little warning. Another manœuvre by beginners that helps to fill cemeteries is the steep climbing turn after a take-off into a fairly strong wind. In that sort of accident the plane goes into a spin with its motor running. When turning with the wind, there may be a momentary loss of speed. If the turn is made while climbing steeply, a spin can start with breath-taking suddenness.
But it can be said for the conventional plane of to-day that if ‘given its head’ it will not get its pilot into trouble. It is when the novice, alarmed by an unexpected development, starts mauling the controls that stalls and spins result, usually with fearsome swiftness.
While the spin is the most treacherous danger for novices, it is not the only hazard. Another is weather. In flying across country one can pass from good to poor flying weather in a relatively short distance. In some parts of the country fogs have a way of closing in under the unwary pilot. Landing in a fog is just another way of gambling with that black-robed gondolier of the Styx.
A third limitation which must be recognized by the careful pilot is the possibility of engine failure. One should always fly high enough so that he can easily glide to a big enough field to make an emergency landing. But the increasing reliability of aircraft engines has stimulated the tendency of all pilots to gamble on the engine. However, the best engines do stop, now and then. If a pilot finds that there simply is no place to set his ship down when that happens, the results are likely to be unfortunate.
I have written at some length on the more grisly aspects of flying, but I do not mean to present a distorted idea of the hazards. A careful pilot, properly trained, knows what he is doing and will not allow his ship to stall or spin accidentally. He will not be caught napping or trapped by fog; nor is he likely to crack up if forced to land.
Flying in the sort of craft now available for amateurs leaves everything up to the pilot, so far as safety is concerned. The operator of the ship must be reasonably skilled, his judgment must be accurate, and he must understand the rudiments of meteorology. But a good pilot is safer flying across country than is a good automobile driver on a cross-country jaunt over crowded highways.
The automobile driver may be possessed of great skill and good judgment, but he is operating a machine which is at the mercy of every moron who may dart out from a blind side road without stopping or looking at the main highway. No matter how good the driver may be, a drunken idiot in another car can suddenly swerve across to the wrong side of the road and kill him in a head-on collision.
The man in the airplane has the whole sky for a highway. His safety or danger is dependent on his own abilities. That advantage in safety for the airplane cannot be disputed. And it is on this foundation that the safe flying machine of the near future will be built.
III
The demand on the pilot’s skill in maintaining safety is not the only hurdle for the airplane to take before it wins wide acceptance. Flying is often frightfully inconvenient. The plane must be kept at an airport several miles from home, and, except in the larger cities, service to and from the airport is erratic. The airplane owner must soil his hands and clothing in greasing rocker arms and in taking care of the numerous other chores required to keep a ship in flying trim. He must keep his mind on his job when he starts the engine; if he grows absent-minded about that detail the propeller may do an admirable job of mechanical homicide. The amateur flier must concentrate on his pastime. He must forget such irrelevant details as dinner hours; when he gets home he must patiently endure the wrath of his spouse, who has kept dinner waiting for forty-five minutes.
There are many heroes who will go through that sort of thing to enjoy golf, tennis, or even ping-pong. But few will do it for flying. I happen to have been touched in the head on the subject of aerial navigation when very young. I never got over it. To me the drumming symphony of power from a roaring airplane engine is the finest music. When I sit in the cockpit of a ship, ‘sock the stick full ahead,’ and ‘pour the coal to her,’ I experience tremendous elation. We take off over a sweet clover field; the ship jumps in the rising air current. Then we cross a stream; the ship dips. A puff of wind drops a wing; a mere touch on a rudder pedal and we are again flying level. The ship seems a thing alive.
Possibly my attitude toward flying is somewhat abnormal. At all events, I discovered long ago that the vast majority do not feel as I do. Their acceptance of flying will be on a utilitarian basis, or not at all. I fully understand the inherent prejudice that many people feel against leaving the ground. But of late many millions have also developed a prejudice against having their brains bashed out in automobile accidents.
In 1914, airplanes were crude contraptions, replete with wires that vibrated and set up tremendous resistance in the air. They were powered with wheezy engines that were more suitable for running washing machines. But the possibilities of aircraft as an instrument of war were so apparent that the best engineering brains of the world were set to work and told to make airplanes that would be deadly weapons. These men were given unlimited money. Nobody counted the cost. All that was asked was airplanes which had speed and the ability to perform.
Thus was born the prototype of the modern military plane. Engines comparable to those of the present were turned out. Instead of the box-kite effects which had been designed, the engineers made clean-looking ships. They learned that wires exacted a tremendous penalty from performance; they cut down the number of wires. The three-wheeled landing gears which sprawled under the primitive cloudwagons of 1914 were replaced with two-wheeled landing gears and a tail skid. The change made them get off the ground faster and perform better in the air; it also made them harder to land, but that was ignored in the interests of getting ships that would help to win the war.
We now have air liners without any wires exposed to the air stream except the radio aerial. They race along at 200-plus miles per hour. The reason — design trends born in the war period have been carried to a logical conclusion.
In the building of aircraft for operation by experts, the war experience was pure gold; but it set up engineering practices which made the production of machines really suitable for the amateur extremely dubious. Before the war, builders of airplanes had been starving; by turning their attention to military machines they found ample funds at their command, so naturally they have been concentrating on the building of military craft ever since. Planes for private fliers have been mere adaptations of military equipment. Some changes were made, of course; but the underlying design trends were all away from foolproof operation. Convenience was ignored. The army did not want convenience; it wanted planes that could climb like homesick angels. That meant that the amateur flier was given an airplane which was deadly unless he knew exactly what he was doing all of the time — and there was too much to know. It was inevitable that the casualty rate should be high.
IV
At the bottom of most spectacular advances in the mechanization of civilization have been found individuals possessed of a great degree of stubbornness. A handful of men declined to be stopped by the jeers hurled at the horseless carriage; now we have the automobile industry.
The same kind of obstinate pioneers have been at work on the problem of making flying the safest means of personal transportation, and their efforts are now nearing the fruition stages. Two methods of making flying safe for the individual are running a race. One embraces changes in the present-day airplane; the other abandons the whole airplane principle of flight and depends upon an entirely different method of sustention. Strangely enough, the man who pioneered in the building of air liners also led in the creation of the airplane for individual use.
Shortly after the war William B. Stout conceived the idea of an all-metal transport plane that would be an economic success because of its weightcarrying capacity. Henry Ford finally became interested in his efforts, and the result was the development, by Mr. Stout, of the Ford tri-motor ships. Among those who fly, the Ford planes are now known as ‘Tin Geese,’ but the term is not one of derision. Though the Ford Tri-motor is not much compared with the air liners of to-day, it blazed the trail in air-line transportation.
Having laid the groundwork, Mr. Stout lost interest in the building of air liners. But five years ago he created a highly significant ship, which he termed the ‘Stout Skycar.’ It had a three-wheeled landing gear and was virtually stalland spin-proof; any normal individual could learn to fly it with two hours of instruction. I would not go on record as maintaining that the Skycar could not be spun; but an accidental spin would have called for monumental carelessness.
Mr. Stout never put his machine into production, because it was of allmetal construction and could have been sold only on a quantity-production basis if the price were to be kept within reason. The country was in the depths of depression, so Mr. Stout turned to the more lucrative pursuit of working out scientific streamlining for automobiles.
But in 1933 another stubborn pioneer appeared upon the national aviation scene. Eugene Vidal was named head of the Aeronautics Branch of the United States Department of Commerce. That governmental agency, by promoting research, played a big part in the development of air-line transportation; and Mr. Vidal thought the government should also sponsor research in the field of private flying.
Like all pioneers, Mr. Vidal is blessed with a great capacity for enthusiasm. At the outset of his career as head of the Aeronautics Branch, he spoke in glowing terms of foolproof airplanes to be sold for $700, so that flying would be made safe and cheap for everybody. His remarks brought down wrath upon his head from those engaged in the manufacture of conventional airplanes for private owners. They accused him of branding all current airplanes as unsafe and thus tearing down the industry he was supposed to assist. So Mr. Vidal refrained from future releases for the newspapers, but he went ahead with his programme of sponsoring the development of a foolproof airplane.
As a result, the Hammond plane has been built. It is an aeronautical descendant of the Stout Skycar, and recent tests in Washington indicate that it cannot be spun. Inspectors of the Aeronautics Branch will soon be flying Hammond foolproof planes. (The term ‘foolproof’ is not altogether accurate, however; for no mechanical contrivance ever built was foolproof.)
Reduced to its final analysis, the process of flying an airplane is one of error and correction. The difference between a skilled pilot and a novice is that the former makes fewer errors and corrects them more rapidly. The Hammond plane is so designed that the errors a reasonably intelligent amateur would make do not get him in trouble, as can be the case with the conventional airplane. The accidental tailspin, treacherous slayer of amateur fliers, is made impossible, and the machine is so built that it handles on the ground as easily as an automobile. The conventional airplane is designed for efficiency in the air; it is tricky on the ground.
V
An obstinate Spaniard, Juan de la Cierva, has done much pioneering in the task of making flying safe for the average individual. He concluded that flying can never be safe until the necessity for a given minimum forward speed is eliminated, and he conceived the idea of capitalizing on the phenomenon of auto-rotation, which produces the tailspin by conventional airplanes. The autogiro, with its familiar windmill mounted above, was the result.
The rotor, as the windmill is called, cannot possibly stop so long as the autogiro is in the air. No position in which the machine can be put will stop the rotor. It is kept in motion by natural forces, not driven by the engine; and it continues to exert lift no matter what the forward speed of the autogiro. That brings the end of stalls and spins. The autogiro is also capable of vertical descent, which eliminates the problem of forced landings; it can be landed on any small level spot.
Cierva did not find success easily. He first conceived the autogiro in 1919, when a comparatively minor flying error by a skilled pilot destroyed a tri-motor bomber he had built at a cost of $32,000. He constructed model after model of his autogiros. Instead of leaving the ground, they rolled over and cracked up. It was not until January 9, 1923, that his first autogiro flew; it left the ground for a few minutes at the Getafe airdrome, near Madrid. He had demonstrated a new method of heavier-than-air flight just a little short of twenty years after the Wright brothers first flew an airplane.
But the autogiro proved to have many faults. Originally it was a compromise; it had stubby wings which supported ailerons, the conventional lateral airplane control, and it also had airplane controls on the tail. Airplane controls, like the plane itself, depend on forward speed for their efficacy. The hybrid autogiro could descend with no forward speed, but its controls were almost without effect when it did so. It was thus at the mercy of every gust of wind.
A few years ago Harold F. Pitcairn, a Pennsylvanian, became interested in the autogiro. He acquired the American patent rights, manufactured autogiros himself, and licensed other manufacturers. It was found, however, that autogiros cracked up with monotonous regularity. These crack-ups did not injure the occupants, because the autogiros landed with little or no forward speed; but crashes did raise havoc with the pocketbooks of autogiro owners. The fact that they could crash and walk away from the wreckage was not enough consolation when every crash cost between one and two thousand dollars.
Furthermore, the autogiro required an engine of several hundred horsepower and could fly only about ninety miles per hour, carrying two passengers. Pilots of airplanes contemptuously termed autogiros ‘egg beaters,’ and the whole idea appeared to be a colossal flop. Anybody but two such stubborn individuals as Cierva and Pitcairn would have quit in disgust. But they did not. They stopped making autogiros for sale to the public, however, and concentrated on research to cure the faults of the machine. Altogether, more than ten million dollars has been spent on its perfection. Cierva has devoted seventeen years to the study of flight by means of autogiros, and Pitcairn has been working on them for nine years.
This fidelity to an ideal has produced a machine which appears to hold great promise. The desertion of airplane principles is complete in the current model, known as the direct-control autogiro. It has no wings, and requires no control surfaces on the tail, but retains an abbreviated tail unit to make flight smooth at high speeds. It is guided in all planes of flight and at all speeds by tilting the rotor. By this new idea the autogiro sponsors claim they have provided positive control at all speeds and in vertical descent as well as after the machine is on the ground.
In eliminating airplane controls, the autogiro makers also stepped up its efficiency. A recent American model has a top speed of 115 miles per hour, using only ninety horsepower, and it carries a pilot and one passenger. Few airplanes can beat that ratio of power to speed and weight-carrying capacity.
But the sponsors of the autogiro were not satisfied to make it virtually crash-proof. They set out to eliminate the inconvenience which has always attended flying. They made the new autogiro with a rotor which can be folded backward along the top; then they added a wheel at the rear and put in a clutch so that the autogiro can be driven as an automobile. The machine they have now developed can be kept in the owner’s garage instead of at an airport. So far its top speed on the ground is only twenty-five miles per hour, but it is reported to be almost as easily controlled as a car.
As a vehicle for use on roads it is primitive; but the fundamentals of a startling development in transportation have been laid. The designers say that speeds of forty miles per hour on the ground, with roadability equal to that of an automobile, will soon be possible. The current model is about half again as long as an automobile, but no wider. In appearance the fuselage (body part) bears some resemblance to a modern streamlined automobile, except that it tapers more to the rear and has three rotor blades folded back along the top. Its propellers do not turn when it is on the road.
Its inability to stall or spin and its controllability on the ground and in the air are not its only tricks. The new autogiro can leap into the air vertically; thus it can be taken out of a small patch of ground surrounded by obstacles. By a hydraulic device the rotor blades can be set at an angle against the air, which produces no tendency to raise the machine. Thus an overspeed in rotation of the rotor, which is started by the motor and disconnected for flight, is attained. Then the rotor clutch is thrown out and the blades are returned to the angle, which produces lift. The autogiro leaps into the air. Jumps of twenty-five feet have been made in calm air. With the aid of a slight wind it is possible to rise almost vertically for one thousand feet.
VI
Will either the spin-proof airplane or the direct-control autogiro prove to be the automobile of the air? If so, which? These questions can hardly be answered with any degree of certainty. Both developments have highly promising aspects; neither has yet withstood the acid test of everyday use.
In some respects the autogiro appears likely to get the call. But it must be remembered that the original hybrid autogiro was widely ballyhooed as the solution to the problem of flight for the average individual; on the basis of demonstrations under ideal conditions, it appeared to be the answer to an amateur flier’s prayer. Instead, in daily use, it proved to be quite impractical. If the new direct-control machine does not have any hidden faults, it will have the advantage of being able to make forced landings almost anywhere.
On the other hand, the new stallproof plane can descend in a steep flight path in case of emergency. It can use a small field, because the threewheel landing gear makes it possible to stop the plane in a short space t hrough the vigorous application of brakes. The conventional airplane cannot stop suddenly after a forced landing, because if the brakes are applied too severely it will nose over and wind up on its back, which is disconcerting to the operator, to say the least. The Hammond airplane can be stopped as suddenly as an automobile. As it lands at only about forty-five miles per hour, it is apparent that it can land in such a small space as to nullify somewhat the advantage of the autogiro in making vertical landings — that is, touching the ground with no forward speed.
The new autogiro is roadable; it can be driven like an automobile on the highways. But. there are no insuperable difficulties in the way of building an airplane with folding wings that could also be driven on the highway. The idea of airplanes with folding wings is not new; such ships have been built in the past to facilitate storage in limited space.
Sufficient progress has been made in the development of foolproof flying machines so that there is little doubt that within a few years a well-proved flying automobile will be available. I believe that by 1946 conservative citizens will be using automobiles that can fly. The preliminary groundwork has been laid. All that remains is the problem of refinement, and a decision, based on experience, as to which type of flying machine will be the most practical and the safest for the casual flier.