How radio-controlled Queen Bee aircraft are used to provide realistic targets for gunnery practice
QUEEN BEE AIRCRAFT can be fitted with floats or with wheel undercarriages. When they are flown without a pilot for gunnery practice with live shells, floats are used because the aircraft will eventually have to alight on the water. The aircraft are never used for gunnery practice over land, because in the event of their crashing or making a forced landing after having been hit, they might fall on people or property.
THE Admiralty began soon after the end of the war of 1914-18 to consider the advisability of using for gun crews some method of training which would provide a target representing as accurately as possible the movements of a real aeroplane across the sky. At first gunnery training for anti-aircraft purposes was carried out in two different ways. One method was to tow behind the aircraft a drogue, fixed to the end of a length of cable, which might be 1,000 feet long. The second method was by “aiming off”. A real aircraft was used as the target but the guns were laid off a certain number of degrees instead of aiming directly at it.
Both methods were equally unsatisfactory when it became necessary to assess the amount of improvement in gun crews under training. In Fleet firing, the value of the ammunition expended may be considerable, and this cost is rightly regarded as an insurance against the possibility of successful aircraft attacks upon the Fleet. In the past the expenditure could not be justified by results. Gunners never knew whether or not they would really be able to bring down an attacking aircraft. Even the officers were uncertain that the complex machinery of gunlaying and director firing would function perfectly when the crews were called upon to bring down enemies attacking from the air.
In response to the Admiralty demand, the Air Ministry undertook the necessary research to produce an aircraft which would fly without a pilot. The automatic pilot had been in existence for some years, and automatic control alone was no novelty either in Great Britain or in America. Wireless control of the automatic pilot had not at that time, however, been applied to any form of transport, on land, at sea or — most difficult of all — in the air.
The problem of launching a pilotless aircraft, and controlling it at a certain altitude, was in itself complex enough without the addition of altitude control. The first target aircraft were therefore arranged to attain a fixed altitude, there to be manoeuvred back and forth along the lines required by the gunners until the aircraft was brought down or its petrol was exhausted.
Although the pilotless aircraft target had arrived it was soon realized that, despite the great advance upon towed targets or aiming off, the conditions were still rather artificial. For example, the aircraft maintained a predetermined height; and for fear of losing the valuable target in cloud, that height was set at about 5,000 feet. The pilotless aircraft thus presented rather an easy target when compared with enemy aircraft which might approach at 15,000 feet and release bombs from some such altitude. At such a height the aircraft might be almost invisible.
A still more serious problem confronted the Admiralty. All nations had developed torpedo-carrying aircraft, and the menace of a formation of torpedo aircraft approaching a Fleet on the beam was a considerable one. Would it be possible for gunners to bring down torpedo-carrying aircraft before they dropped their deadly cargo? This question would remain unanswered until pilotless aircraft could be developed which would carry out the same manoeuvre as an attacking torpedo-carrying aircraft.
Aircraft carriers of all nations were equipped with at least one squadron of single-seat fighters, in addition to the other types of seaborne aircraft. The fighters’ method of attack on warships of all types was to dive at over 200 miles an. hour, releasing light bombs before pulling out pf the dive, or alternatively spraying the decks, gun crews and fighting tops with bullets from their multiple machine-guns. Here again, no one could say whether or not antiaircraft gunners could bring down these high-speed fighters, either before or during the power dive.
Having realized the limitations of existing targets, pilotless or otherwise, the Air Ministry put forth a great effort to produce an aircraft which at least in some measure should provide a more realistic target. Instead of building a small wireless-controlled aircraft specially for the purpose, three full-size aircraft of the type known as Fairey IIIF were selected, and experimentally equipped with automatic pilots and the necessary wireless control gear.
These aircraft were provided with two undercarriages. One undercarriage was for use on land aerodromes so that prolonged testing could be carried out while the aircraft was carrying a human pilot and an observer. The other undercarriage was for use at sea either when the aircraft had been flown off the water by a human pilot or shot into the air by the aircraft catapult of a battleship or cruiser.
THE FIRST FULLY-CONTROLLABLE PILOTLESS AIRCRAFT were of the Fairey III F type, and were known as Fairey Queens. Three Fairey III F aeroplanes were equipped with the necessary radio apparatus and were the first radio-controlled aircraft to be catapulted into the air. Because these aircraft were expensive — each was worth more than £5,000—the possibility of a crash was a serious matter. This led to the production of a cheaper target in the form of the Queen Bee aircraft.
These were the first pilotless aircraft intended to be catapulted at high speed instead of being propelled into the air by specially made mechanism. As each aircraft was worth more than £5,000 when fully equipped, it was necessary to devise also some means by which the aeroplane — if it were not first shot down — could alight on the sea without damage to itself when shooting practice was over. From these Fairey Queen aircraft, a rather expensive type to risk losing so frequently either by bad landings or by being shot down, a smaller and cheaper target has been developed. The type is known as the Queen Bee. The aircraft itself is of an inexpensive stock type, which can be bought in quantity if required. Years of thought and experiment have, however, been applied to the production of the automatic and radio control which ensures that the aircraft will correctly obey 1,000 signals in succession. That is the test applied to each aircraft before it is considered suitable for pilotless flight.
Press-Button Control
When the automatic control has been installed, therefore, the aircraft is given a prolonged series of tests, with a human pilot in one cockpit and the automatic pilot in the other. The majority of Queen Bee aircraft are intended for use at sea; but in the testing period they are fitted with a land undercarriage and are generally flown off a land aerodrome by one of the test pilots.
Control is effected at sea from the aerial of a battleship or cruiser, and on land from a similar type of aerial arranged at an equal height. It would be possible to control a Queen Bee merely
by sending the appropriate signals from a wireless key. Nowadays the signals are sent out automatically from a small portable switchboard, and each signal is initiated by the pressure of a button.
The buttons have labels indicating their various purposes and include those for left turn, right turn, straight flight, climb, dive and level flight, as well as. others for special purposes.
Let it be now supposed that the tests are satisfactorily completed and that the aircraft is ready to be flown pilotless. It would be possible to adjust it so that it could fly off its own land aerodrome. In such an event, however, if anything went wrong, the pilotless aircraft might crash in some centre of population. To obviate this, the aircraft is catapulted either from a ship at sea, or from a land catapult pointing out to sea.
When firing is in progress, therefore, all the spent shells will fall into the sea some distance out. If an effective shot should damage the controls of the Queen Bee to such an extent as to cause a crash or forced landing, the mishap would take place on the water instead of on land.
The first process, therefore, after completion of the tests is to convey or fly the Queen Bee to the point at which the aircraft can be mounted on its catapult. If the aircraft is to be shot at by Army gunners, the Queen Bee is fitted with a land undercarriage, and flown to the nearest aerodrome to the gunnery practice camp. It is moved on wheels to the catapult and lifted with a crane or a set ot sheerlegs. After the machine has been mounted on the catapult the wheel undercarriage is replaced by floats.
Queen Bees for use with the Navy spend most of their working life on floats. They can be flown off the water at one of the testing stations on the south coast of England, and alight alongside battleship or cruiser as required, there to be hoisted by a crane into position on the catapult. The catapults of cruisers are near the centre of the vessel; those of battleships are frequently at the extreme stern. In either instance the catapult can be rotated through a wide angle, so that the aircraft can be headed straight into wind if the vessel is stationary.
THE DE HAVILLAND TIGER MOTH is the standard aircraft from which pilotless Queen Bee aeroplanes are produced. They can still be flown by hand when the radio-controlled apparatus is installed. For test purposes a wheel undercarriage is fitted and a human pilot flies the aeroplane off the ground. At a suitable height he relinquishes control to the radio-operated automatic pilot.
It is advisable, however, to take advantage of the wind produced by the forward motion of the vessel. When it becomes necessary to carry out a launch at sea, the catapult is headed into the resultant wind, that is, the combination of the movement of the ship and of the angle of the true wind.
Launches from the land are carried out with a long and powerful catapult. Even then it may be necessary to wait for days until the wind is more or less in the right direction, as a launch towards the land would not be made. There is a fairly wide range of movement of the catapult over the angles pointing out to sea.
At sea it is not necessary to wait for a change in the direction of the wind. But at sea a launch is frequently deferred until the sea is sufficiently calm to ensure that a reasonably good alighting can be made by a pilotless aircraft, and that boats will live in the sea when sent away to bring in a pilotless aircraft after it has alighted on the water.
Catapulted with Cordite
Assuming that there is sufficient wind to ensure a satisfactory launch and yet not so much as to cause a rough sea, the only other desirable feature of the day is a clear sky or, better still, light clouds at great height. If the clouds are too low, there is a slight risk that the controlling officer may lose track of his Queen Bee; alternatively, the aircraft must not fly so far below the clouds as to provide too easy a target.
When the weather conditions are satisfactory, the catapult is turned into the wind. The catapult is provided with a long extension, and this is wound out. The Queen Bee on its carriage is wound to the inboard end of the long runway, the aircraft being held in two sloping slots engaging with spools mounted on the fuselage. All preparations are made to ensure that the automatic control will work satisfactorily. The engine is then started up and given time to attain an even temperature. While this is being done, the opportunity is taken of checking the accuracy of the signals received by the aircraft from the portable switchboard, now standing on the bridge of the controlling vessel.
Some of the signals sent out from the small switchboard have more than one result when conveyed to the automatic control from the aerial of the Queen Bee. For example, the signal “climb” involves not only a change of attitude of the aircraft, but the extreme opening of the throttle to ensure maximum engine speed.
The first active signal, as distinct from trial signals, given to the aircraft while it is on the catapult is “climb”. When the engine has been opened out to the full in response, the bridge instructs the catapult crew to proceed with the launch. This instruction is transmitted by hand signal, by flag signal, or by telephone.
The gunner pulls a lanyard, the cordite burns with a loud hissing noise, and the Queen Bee on her carriage hurtles along the catapult track and sails gracefully upwards.
It is usual to make the aircraft climb for at least 500 feet before giving the first signal, which is normally a left turn. While the Queen Bee is attaining height, the ships detailed for gunnery training assume a line-ahead formation with the controlling cruiser approximately in the middle. At 10,000 feet it is extremely difficult for the controlling officer to see the Queen Bee even in normal conditions. If on a sunny day the aircraft were flown across the face of the sun it would be invisible.
It is usual therefore for the Fleet to cruise with the sun on one side and the aircraft flying on the other. The sun is then shining at the backs of the gunners and of the officers responsible for the control of the aircraft.
It is possible to simulate closely the conditions in which an attack by aircraft on a fleet would be made. During the war of 1914-18 pilots would change course as soon as they saw the flash of an anti-aircraft gun below them. Similarly the controlling pilot is able to change the course of his aircraft immediately target practice has begun. He will maintain a straight or devious course, as required by his instructions, to make the target practice elementary or more difficult. The practice is again made more difficult by an increase in the height at which the Queen Bee is flying. It is easier to hit a pilotless aircraft flying fairly slowly against the wind than when it is on the reverse course, travelling with the wind at a much higher speed. It is usual for ships to shoot one at a time. If this were not so, and a lucky shot brought the aircraft down, there would be some doubt as to the gun crew responsible. The number of shots to be fired is laid down, and two anti-aircraft guns fire at once. Now that Queen Bee targets have been in use for several years, the accuracy of the shooting is considerable. Whether the aircraft is being “jinked” or flying a straight and level course, the black puffs of high explosive creep inexorably nearer, two at a time appearing against the blue and white of the sky. If the gunners are successful in obtaining a close bracket, in which one of the shells bursts above and the other below the aircraft, the end is often near.
If each ship completes her practice without having brought down the Queen Bee it is possible that further firing may be carried out at a lower altitude. Alternatively, instead of a simple high-altitude practice, the Queen Bee may be brought close to the surface of the sea to simulate torpedo attack. Or the aircraft may be directed to make a series of dives in imitation of the type of attack likely to be made by single-seat fighters upon exposed gun crews on the decks.
THE CONTROL DESK for the Queen Bee has a series of push buttons each of which automatically sends out the code signal which produces a certain manoeuvre. The buttons include those for left turn, right turn, straight flight, climb, dive and level flight, as well as others for special purposes. The aircraft have to obey correctly a thousand signals in succession during their tests.
Aircraft on bombing duties may fly at great heights, when they can be reached only by high-altitude high-angle gunfire. The attack of single-seat fighters, screaming down in straight or spiral dives, is met by multiple machine-guns. The counter to the torpedo-bomber is believed to be the nine-barrel pom-pom, firing hundreds of 1-lb. shells a minute.
Two or three miles away from the vessel to be attacked, the Queen Bee completes its dive or glide and levels out to fly parallel to the surface of the sea and probably less than 100 feet above it. The aircraft is now nose-on to the gunners and a difficult target; but the torpedo bomber must be only about 20 feet above the water to make a successful attack. The multiple pom-pom provides a dual defence by the curtain or barrage of fired shells as well as by the great columns of water rising from the explosion of these shells on the surface of the sea. Either by direct hit or by the splash of these explosions, the torpedo bomber is to be brought down or deflected from its intended course; in either event a torpedo attack would certainly fail. So many shells are in the air at once that they are visible from certain angles, especially from behind the gun. Equally visible and somewhat awe-inspiring is the curtain of spouting water between the aircraft and the fleet. It has not been thought necessary to fly a Queen Bee into this wall of water to observe the effect, but a Queen Bee has been brought down by a direct hit by one shell of a multiple pom-pom while simulating the attack of a torpedo bomber.
The shell passed through the aircraft from side to side, but without exploding. In its flight it broke a bunch of cables about three inches in diameter, and thereupon cut off all controls from the aircraft. Despite this handicap, the aircraft alighted on a calm sea, was recovered virtually undamaged, and was able to carry out further target practice only one day later.
Direct hits are more frequent with high-altitude gunnery. Here the explosion is so intense that the aircraft bursts into flames and is in effect annihilated. Gunnery practice with the multiple machine-gun is generally carried out by firing at drogues, as the ratio of the cost of ammunition to the cost of the Queen Bee is so much less than when 6-inch guns, for example, are involved.
A fleet putting to sea for gunnery practice may take as many as six Queen Bees. It does not follow that even a single one of them will be brought down.
If the shooting is really good, or the target practices elementary, one or more of the aircraft may be lost, and fresh ones are available and ready to be catapulted immediately so that the practice may be carried on without the Fleet having to return to port. It follows that in a reasonable number of practices the aircraft in the end is not badly hit, and is required to alight normally on the sea.
The flagship signals “cease fire”. Almost instantly the aircraft dips into a long glide towards the surface of the sea. If that glide will carry it too far away from the controlling vessel, an instruction may be signalled which will turn a straight glide into a spiral.
The controlling officer keeps his Queen Bee within about 500 yards of the cruiser and straightens out the spiral into a glide into wind from about 500 feet. To see a pilotless aircraft alight is always an enthralling spectacle. The Queen Bee descends in a straight glide, unhampered by the bumps so frequently found over the land. When about 25 feet above the water, its landing device comes into action, switches the engine off, and pulls the control column back, so that the aircraft makes unaided what would be on land an excellent three-point landing. Queen Bee flights are equipped with one or more speedy power boats, and long before the aircraft alights the power boat has been lowered into the water and is on its way so as to be close to the point at which the aircraft will arrive. Towing lines are fixed to the shackles on the floats and, with a pilot in its cockpit, the Queen Bee is towed back to the cruiser. In some instances manually propelled boats may be used to tow the aircraft.
When the aircraft is alongside, the officer in the cockpit catches the descending hook from the crane, and fixes it into the shackle on top of the upper wing. Within a few moments the Queen Bee is hoisted from the water.
During 1937 a much more speedy type of aircraft was made available for target trials. The aircraft has been referred to in the Press as the Queen Wasp, though this name may not have yet been officially approved. The engine is a 355 horse-power Armstrong Siddeley Cheetah IX radial. Like the Queen Bee, the latest target aircraft can be used either with wheels and spats, or on floats.
REASONABLY CALM WATER is required for the flying of radio-controlled aircraft. There are two reasons for this. If the water were rough the aircraft might be damaged when alighting; further, the boats which tow the aircraft, and which go out to retrieve them immediately they have alighted, would have difficulty in carrying out these operations.
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