Deck landings, parachutes and gyroplanes involve the use of many ingenious inventions
AEROPLANES WERE DROPPED FROM THE R 33 by means of a main release at the point of balance. A successful launch was carried out with Squadron Leader de Haga Haig in a light aeroplane. He remained in the airship during the take-off and climb and sat in the cockpit of the aeroplane later. The release was made with the airship hovering, and the aeroplane fell away in a steep dive, out of which Squadron Leader Haig immediately pulled it.
INVENTION finds perhaps its greatest scope in aviation. There has never been a science offering greater opportunities to the practical engineer with a bent for original solutions to essential problems. Nor is there any sign at present of a slackening of inventive effort. On the contrary, as time goes on the ingenuity and the originality of aeronautical inventors seem to increase.
Probably the most spectacular air invention is exemplified in the Short-Mayo composite aircraft. An earlier achievement, when-a Bristol single-seater was attached to the top plane of a large flying boat, was not a composite aircraft and did not therefore — as has been erroneously stated — anticipate the Short-Mayo device.
The Bristol was carried up by the flying boat and then, when height had been attained, it was released. The Bristol did not cooperate with the flying boat by lending its engine power and wing surface to help; thus it was not in the true sense a component of a composite aircraft, but merely an ordinary aircraft attached to another ordinary aircraft.
That does not detract from the merit of the experiment. It was intended to open the way to the use of a small single-seater fighter for bringing down Zeppelin airships. The idea of mounting the fighter on the flying boat was, in effect, to give it the necessary range. The object was to release the fighter only when the flying boat had brought it within striking distance of the airship. This war-time test was successful and the Bristol took off without difficulty.
Another rather similar test was made with a B.E., which was attached under an airship. The airship lifted the aeroplane off the ground and, after height had been attained, the B.E. pilot released his machine, started his engine by diving and was free to conduct an independent military operation. This experiment, however, ended in disaster. The B.E., for some unexplained reason, did not drop from the airship on an even keel, but went into a spin.
Later experiments in dropping aeroplanes from airships were successful. Various experiments were made with the airship R 33 and a light aeroplane piloted by Squadron Leader de Haga Haig. The aeroplane was attached beneath the airship with a main release at the point of balance and the pilot remained in the airship during the take-off and the climb. Just before it was decided to release, he climbed down into the cockpit of the aeroplane.
The release was effected with the airship hovering. The light aeroplane fell from the airship in a fairly steep dive from which the pilot immediately extricated it.
To signalize the success of the experiment to the anxious watchers on the ground, Squadron Leader Haig then did two loops, glided down and landed. In a later experiment the airscrew of the aeroplane was damaged, but not seriously. The pioneer work had been done, the necessary knowledge accumulated, and it was possible to devise apparatus for dropping much larger fighters from airships. This led to the idea that the airship would be used in war as an aircraft carrier. The United States developed the scheme to enable an airship to carry several aeroplanes; but at a later date the whole plan of carrying aeroplanes in airships was re-examined and now it is regarded in a much less favourable light.
Other taking-off experiments, as they might be called, include the famous one with the towed lighter made by Air Commodore Samson. This also was with a view to using single-seater fighters for defence against raiding Zeppelins. The single-seater was attached to a lighter which was towed behind a destroyer. The take-off was effected by towing the lighter at high speed and into the wind and thus providing a relative airstream sufficient to give the machine lift without a run. On one occasion Air Commodore Samson was nearly drowned when trying this experiment, but the take-off was successful later.
There have been almost as many experiments in landing aeroplanes as in taking them off. The object of the experiments has nearly always been the same — to enable aeroplanes to land in a restricted area. Adolphe Pegoud, the daring French experimental and aerobatic pilot (see the chapter “The Art of Aerobatics”), landed an aeroplane on a wire by means of a special hook.
There were also the numerous experiments which led to the present technique of deck landing. At one time the aeroplane was caught by cables strung fore and aft along the landing deck. Special hooks engaged these cables to prevent the machine from going over the side.
Slow Flying
Then there was a period during which no arrester gear was used and the aeroplanes merely relied upon the relative airstream and upon their wheel brakes to pull up quickly. Finally there were the wires running from side to side across the deck which were engaged by a hook extended under the aeroplane. The decelerative effect was progressively increased until the aeroplane was brought to a standstill. The subject of deck landings is dealt with in detail in the chapter on “The Fleet Air Arm”.
“Autogiro” aircraft have been used for deck take-offs and deck landings. The most remarkable of these experiments was made in an Italian harbour, in an Italian warship, by a British pilot, R. A. C. Brie. A small landing platform was built in the warship. While the ship was at anchor, with no strong relative airstream to help him, Brie took off and landed with complete success. It was the first time this had been done. Later, Brie took off from and landed on the deck of a British aircraft carrier while she was steaming in the Strait of Dover.
Landing experiments have been closely linked up with slow-flying experiments and these have been mainly concerned with the use of slotted wings. Probably the most sensational experiment was that made at Stag Lane Aerodrome, Hendon, by Captain Geoffrey de Havilland. Captain de Havilland’s machine was a Moth fitted with wing slots. He had announced beforehand that he would put the Moth into a stalled position, hold it there and let it sink to the ground.
An elementary knowledge of flying is sufficient to make it clear that such a manoeuvre with a normal machine is dangerous. For when a machine is stalled or nearly stalled, it is on the point of dropping its nose and going into a steep dive. If once it does that, it cannot be extricated without a good deal of free height.
THE TRICYCLE UNDER-CARRIAGE now used on some aircraft was adopted only after many experiments. This photograph shows a tricycle undercarriage fitted to a Monospar aircraft. With this type of undercarriage the landing of an aeroplane is considerably simplified. The two rear wheels are arranged behind the centre of gravity so that the aircraft remains balanced on the three wheels when it is standing on the ground. The tail does not rest on the ground.
At this demonstration, however, Captain de Havilland kept his word. At something below 1,000 feet he put the machine into a stalled attitude, with the nose rather up, and held it there. The wing slots could be seen to open and the machine, instead of putting its nose down, kept in the stalled position. The theory of the wing slot had been proved. The sinking speed was, however, much greater than had been expected and the machine — still in the “flat” position — struck the ground with considerable force. The undercarriage crumpled up and so did a good many other parts. Captain de Havilland stepped from the wreckage unhurt. Other experiments have been made with a view to enable a machine to alight in snow or fog. Some of these tests were made with a flying boat and were known as the “hanging stick” experiments , some were made with an Avro landplane.
The flying boat experiments depended upon a stick extended below and behind the machine. The machine, after having been brought to a given point by radio, was put into a gentle glide. When the end of the stick hit the water, the control column in the machine was automatically pulled back and the machine levelled out for landing. Several failures were experienced with this device, as with most new devices, but finally it became possible for flying boats to alight with reasonable accuracy.
In the Avro experiments a weight was hung below the machine. When this weight touched the ground it gave the pilot a signal which warned him to pull back the control column and flatten out. This device worked well. It was used in dense fog and proved successful. The machine was first brought by wireless to a predetermined position over the aerodrome boundary. The position of the Avro was then fixed with greater accuracy by means of a sight taken by the pilot when still above the fog on a balloon let up expressly for the purpose.
With the aid of this balloon, the pilot fixed his position and his height, and then he put the machine into a steady glide at a given speed. He waited for the signal, which was given when the weight at the end of the cable struck the ground; then he flattened out. Considerable courage was needed by the pilot who used this method for a landing in dense fog, but it was an example of the kind of experiment which Farnborough test pilots are frequently called upon to perform. An experiment with landing made in the United States of America used a huge parachute which was ejected from a container in the top of the fuselage and which then bore the entire aeroplane gently to the ground. This experiment, according to the reports which reached Great Britain, was successful.
The most generally used slow landing device today, the wing flap with or without the slot in front of it, can scarcely be said to have been the outcome of any single experiment. It was rather developed after numerous experiments.
Static Line Parachute
Some of the devices which seem ordinary today demanded some striking experimental work before they were brought into use. The free parachute, for instance, was accepted as the best form only after numerous experiments, some of them worthy of note. The parachute with which the flying Services were formerly familiar was known as the static line parachute. In 1917, when it was heard that the Germans were to use parachutes for their pilots, the static line type was the one first considered.
With this type, the pilot, when he jumps from the aeroplane, wears the parachute in a pack on his back. A light line is folded within the parachute and its end is attached to some part of the aeroplane. After the parachutist has fallen a given distance, the line is jerked taut and the parachute is forcibly pulled out of the container.
This type of parachute had obvious resemblances to the fixed type used in balloons and it was thought at first that it was the only possible type for aeroplanes. A good deal of experimental work was done with it and some experimenters jumped from aeroplanes in various positions to prove that the static line parachute would always function.
Then came the free parachute and again the experimenters had to do their jumps from strange positions to prove its worth. Probably the most notable jump was the one done from a Bristol Fighter while the pilot was holding it in a spin. The parachutist made this jump successfully ; but at the time, when little was known about the action of parachutes when used in such drastic conditions, a good deal of courage was needed.
AN EARLY “AUTOGIRO” AIRCRAFT, a class of machine which has been used for numerous experiments including deck take-offs and landings on a warship. This feat was accomplished by a British pilot, R. A. C. Brie, in an Italian warship in an Italian harbour. The experiments were made with the ship at anchor so that there was no relative airstream to help the pilot.
Courage was needed also in a remarkable experiment at Orfordness, Suffolk, towards the end of the war of 1914-18. This was of a device for protecting aeroplanes against balloon barrages. The machine used was an F.E. (Fighting Experimental); this was a large biplane with a pusher airscrew and a water-cooled engine. The F.E. was provided with a sort of heavy “bowsprit” and a heavy wire was stretched from wing tip to wing tip and across the point of the bowsprit. This formed a V in front of the machine and the idea was that, if the machine hit a balloon cable, the cable would be deflected by this V and the machine would continue on its way unharmed.
Practical pilots, however, ventured to suggest that the device might not work as well as the inventor thought. So it was decided to test it. A balloon was let up at Orfordness and a pilot took up the F.E. and deliberately flew it into the cable. There was a long electric spark; the F.E. was suddenly retarded and thrown into a spin.
The pilot extricated the F.E. from the spin just before it struck the ground and he landed successfully. The balloon cable had been successfully deflected, but it had cut into one of the wing tips. Although the protective device was proved to be fairly successful by this remarkable experiment, it was never used on active service, Had the war continued and the use of balloon barrages been intensified, however, it might have been used. Experiments in aviation were not confined to the aeroplanes during the war, but included many other related matters, chief among them being armament. The large calibre Coventry Ordnance gun was tried in a D.H.9. Then there was the ingenious series of experiments with “upward shooting”. This was intended for the defence of London against enemy bombing aeroplanes.
Imprisoned in Ice
Machine-guns were fixed in single-seater fighters so that they fired upwards at an angle of 45 degrees. They could not be “aimed” in the sense of being turned in any way. The idea was that, if the pilot of the single-seater flew below one of the raiding bombers, kept a steady course and kept the raider in his sights, the allowances for the flight of the bullet would cancel out and accurate shooting would be obtained.
The experiments were made with a Camel fitted with upward-firing guns and a towed flag target and they suggested a high degree of accuracy in fire. The theory looked attractive because, if the single-seaters could remain below the attackers, they would have less climbing to do and would get into action earlier. Moreover they would — in theory — be able to go on shooting until they brought down the enemy.
The method used was not the same as that devised in the experiment. It seemed that the direct attack at close range by a machine with a margin of performance over that of the enemy machine was more likely to be successful than the attack by upward shooting.
After the war the biggest air experiments were with the airships R 100 and R 101. Then there was the work with the Cierva “Autogiro” aircraft, with the Hafner and with the Kay gyroplanes. Further experiments were made with the balloon barrage. Attention was given to the perfecting of devices for protecting aeroplanes against the effects of ice accretion. Certain pilots flew their aeroplanes in ice-forming conditions until the aeroplanes were covered with ice and the cockpit covers were sealed with the ice. A pilot thus imprisoned would have been unable, had the need arisen, to escape by parachute. Great courage was needed for these experiments.
Experiment never ceases and every step forward in aeroplane design demands experimental work of some kind. The recent tendency to adopt the tricycle undercarriage (see the chapter “Fixed Wing Machines”) demanded much preliminary work in landing and taking off machines of this type. Every new blind-landing device and every new parachute has been tried by some courageous experimenter.
EXPERIMENTS HAVE BEEN MADE with many forms of arrester gear to bring an aeroplane to rest after it has landed on the deck of an aircraft carrier The system in use today has transverse wires running across the deck at regular intervals. On the aeroplane is a hook device which engages with one of the wires. The wires are hydraulically controlled so that although they give slightly, the aeroplane is quickly brought to a standstill.
