In May 1914, Archibald Montgomery Low demonstrated a primitive form of television, which he named “Televista”. It employed a selenium semiconductor to convert light into electrical impulses but proved too slow to cope effectively with moving images. After the outbreak of war, he tried to adapt his ‘Televista’ system into a range finder to control coastal batteries. In 1916, when the Zeppelin raids were causing widespread concern, he was approached by Col Cadell, then Director of Aircraft Equipment, to see if he could adapt his wireless system to remotely control a flying bomb which could be guided into position close to an enemy airship and then exploded, thus destroying it. Low happily transferred to the Royal Flying Corps, enjoying what he regarded as its youthful enthusiasm and infectious camaraderie.
Archibald Low at work on some of his wireless apparatus.
Based at the experimental unit at Feltham, Low worked in comparative secrecy to develop his apparatus. Gen. David Henderson, Director General of Military Aeronautics, suggested that the device be named the “Aerial Target” so that, should its existence become known to the enemy, it would be thought to be some drone for gunnery practice – and by that name, it has always been known.
Low devised, making the best possible use of the technology then available, a variable spark transmitter and receiver, which allowed sequential control of a number of servos, which, in turn, controlled the rudder and elevator. Providing control in the rolling plane would have rendered response much slower, so it was decided to make the vehicle inherently stable so that it would bank automatically.
The first attempt was made by assembling an aeroplane out of spare parts, but this failed to take off as the engine’s ignition system caused interference with the wireless signals, so, in January 1917, Low met with designers at the Royal Aircraft Factory who devised a small shoulder wing monoplane powered by a 35 hp twin cylinder engine and fitted with a skid undercarriage. Take-off was to be along a track, and, in active service, the device would not be required to land, so no wheels were provided.
Six examples of the drone were built, to which the serial numbers A8957-8962 were assigned, although it seems that these were never painted onto the aircraft. The completed machines were sent to Feltham for the wireless systems to be fitted, and then, on 5 July 1917, the first was taken to Northolt for assembly and testing.
One of the six ‘Aerial Targets’ inside the workshops. The lines running chordwise on the wings and vertically on the rear fuselage are the wires that acted as the wireless’s aerial.
The next morning, the fuel tank was filled, the centre of gravity measured, and the tailplane incidence set in accordance with the results of wind tunnel tests to maintain level flight. Engine problems delayed take off until late in the afternoon, by which time it was discovered that the wings had warped from being stood all day in the sun and so had to be trued up. Finally, by 6.30 pm, all was ready, and although the wind was gusting at up to 15 miles/hr, it was decided to conduct the test anyway. However, further engine problems delayed the test until 9.15 pm. The machine took off after travelling about half the length of the track and began to climb at an increasingly steep angle. Although the ‘elevators down’ signal was immediately sent, the machine stalled and crashed before it could be acted upon. The problem, it was later decided, lay in a difference in flying characteristics between the model with which the wind tunnel tests had been conducted and the full-sized machine.
The second example was tested on 25 July when, after the wireless had been fitted, the tanks filled and the centre of gravity measured, the tailplane incidence was set, and a take-off was attempted. This time, the machine accelerated down the track, the tail lifting as it did so, and on reaching the end of the track, it carried on, tail high, across the field until its progress was halted by a wire fence, with sufficient resulting damage to end the trial.
Two days later, another Aerial Target drone was taken to Feltham and made ready for testing the following day. With the wireless system fitted and the tanks filled, the centre of gravity was found to be in exactly the same position as on the previous trial, and so the tailplane was confidently set at a slightly more negative angle. This time, the machine had accelerated to close to take-off speed when the engine began to misfire, reducing the speed. At the end of the track, with the machine still on the ground, the undercarriage collapsed, breaking the propeller. Nonetheless, from its attitude on the launch track, the team concluded that the tailplane setting was now correct. However, although seemingly on the point of a successful launch and a real trial of the wireless control system, the tests were discontinued, possibly because it had been found practical to bring down Zeppelins by more conventional means.
The three undamaged airframes remained at Farnborough, and on 21 January 1918, a request was made to be allowed to continue the trials, but this was not sanctioned. Instead, sometime after the end of the war, an attempt was made to convert the device into a self-contained flying bomb to be launched from a ship. In 1924, a new airframe with a more powerful engine was designed, but again, the trials were discontinued when apparently on the point of success.
One of the original Aerial Targets, believed to be A8962, was later converted into a manned aeroplane by adding wheels, providing a cockpit placed at the centre of gravity, and including conventional flight controls, including ailerons. The machine passed through the hands of several owners before being acquired by a Mr Shelley, who transported it back to his home in Billericay by removing the wings and towing the fuselage behind his car, a passenger in the backseat holding the tailskid, with the tailplane over his head. Shelley never flew the aeroplane nor placed it on the civil register, and it was eventually broken up and the engine sold.