P.Hare Royal Aircraft Factory (Putnam)
Conceived late in 1916, this was a radio-controlled, pilotless aeroplane intended both for defence against Zeppelins and as a flying bomb. In the former role it was planned that it would be controlled from the ground, but in the latter role control from an accompanying manned aeroplane was also considered. To disguise its intended purpose it was always referred to as the Aerial Target.
Its wireless apparatus was designed by Capt Archibald M Low of the RFC's wireless unit at Feltham, whose idea it was. His attempt to build the aeroplane himself, largely from spare parts, had met with no success, and the assistance of the Royal Aircraft Factory had therefore been requested. The project was undertaken by Henry Folland, although much of the detail work was drawn by his assistant, H E Preston. The Farnborough design was a small shoulder-wing monoplane powered by a two-cylinder ABC Gnat of 35hp, with numerous radio aerials running vertically down the fuselage sides and chordwise across the wings. In the interests of simplicity, lateral control was by wing warping, and generous dihedral ensured lateral stability.
Six examples, A8957-A8962, were constructed, the first being delivered to RFC Northolt, where the trials were to take place, on 5 June 1917. The intention was that the machine should be trimmed to take off and climb away to a reasonable height before radio control was attempted. Extensive windtunnel tests on models had indicated what the necessary tailplane incidence should be, but the first flight, on 6 July, consisted of an almost vertical climb away from the launching rail, followed by the inevitable stall and consequent crash, before the radio control system could take effect. It was clear that the still imperfectly understood aerodynamic differences between scale models and full-sized aeroplanes had resulted in insufficient tailplane incidence.
A second example was tested on 25 July but failed to take off, merely running along the ground until its undercarriage finally collapsed, the tailplane adjustment having been somewhat overcorrected. A third attempt, with the tailplane finally set at the correct angle, was made three days later, but unfortunately resulted in yet another crash when the engine failed just after take-off. Although damage was confined to a broken propeller and some easily repaired undercarriage components, official interest in the project appears to have diminished and no further trials are recorded as having taken place, although the project was resurrected briefly in the early 1920s.
One example was later converted to a manned aeroplane by No 3 (Western) Aircraft Depot at Bristol, and was fitted with a wheeled undercarriage and ailerons. As a rebuilt aircraft it was allotted a serial number from a batch allocated for that purpose. It received the number B8962, with numerals similar to those of its original, uncertain identity, and this has caused much ill-founded conjecture among latter-day historians.
By 1934 it had been disposed of, and was owned by Mr Ron Shelley of Billericay, but it was broken up without appearing on the civil register.
span 22ft 0in; length 20ft 4in; height 5ft 10 1/2in;
chord 5ft 2in; incidence 6°; dihedral 5°.
J.Bruce British Aeroplanes 1914-1918 (Putnam)
THE Royal Aircraft Factory Aerial Target is probably the best-known of all the small aeroplanes which were built for Professor A. M. Low’s experiments with radio-controlled aircraft. The aim of these experiments was the evolution of a flying bomb but, in common with its contemporaries, the little R.A.F. monoplane was known as an Aerial Target in order to conceal its true purpose.
Designed by H. P. Folland, Farnborough’s A.T. was a graceful shoulder-wing monoplane powered by a 35 h.p. A.B.C. engine. It had a fuselage of rectangular cross-section, terminating in a tail unit reminiscent of that of the S.E.4: the fin surface was symmetrical above and below the fuselage, and a high aspect-ratio rudder was fitted. The main undercarriage consisted of simple light skids; and the landing-wire bracing of the mainplanes consisted simply of spanwise cables between the port and starboard wings: there was no cabane structure. The wings had a generous dihedral angle, for it was desired to obtain stability without the use of gyros. Wireless aerials were fitted as chordwise wires on the mainplanes and on the rear fuselage.
A number of these Folland-designed A.Ts were built: six were constructed at the Royal Aircraft Factory in 1917, and were probably the Aerial Targets for which the serial numbers A.8957-A.8962 were allotted. Others may have been made by outside contractors.
In the post-war years an attempt was made by C. H. Lowe-Wylde to produce a light sporting single-seater by modifying a Royal Aircraft Factory A.T. A cockpit was made, ailerons were fitted, and a wheel undercarriage replaced the original pair of skids.
Manufacturers: The Royal Aircraft Factory, Farnborough, Hants.
Power: 35 h.p. A.B.C.
Dimensions: Span: 22 ft. Length: 20 ft 4 in. Height: 5 ft 10 1/2 in.
Production: Six Aerial Targets were built at Farnborough in 1917.
Serial Numbers: A.8957-A.8962.
R.F.C. Experimental Works Radio-controlled Aircraft
MANY of the experiments conducted by Professor A. M. Low before and during the 1914-18 war were prophetic in their nature and object, none more so than his work on the production of a radio-controlled flying bomb. His experiments began in 1916.
As early as 1914, Professor Low had given a demonstration of the principles of television in London. When war broke out he was asked by the Ordnance College, Woolwich, to adapt these principles for artillery purposes. His experiments met with a fair amount of success but were never followed through to an operational conclusion, for the scientist was asked by General Caddell of the War Office to investigate the possibility of using a form of television to direct a flying bomb.
Second Lieutenant Low, as he forthwith became, began to conduct his new experiments with the assistance of Captain Poole, Lieutenant Bowen and Lieutenant Whitton. The work was carried on in great secrecy; police and military guards were provided; and Sir David Henderson, the Director-General of Military Aeronautics, said “Now, Low, we must think of some thundering lie to conceal the fact that we have a new weapon. Let us call it the A.T.; people will think it is meant as an aerial target.”
Much preliminary experimental work had to be done with wireless transmitting and receiving apparatus, during which time the scientist and his assistants were moved first to Brooklands and later to Feltham.
The first radio-controlled aeroplane was a little monoplane powered by an uncowled 50 h.p. Gnome rotary engine. The fuselage was a tubular structure of original construction, but most of the rest of the aircraft consisted of components adapted from parts of old biplanes. Details of the undercarriage are obscure, but it probably consisted of nothing more than a pair of skids. The Gnome engine gave a good deal of interference in the radio apparatus, however, and improvements were sought.
The full details of the development of the aircraft are probably forever lost, but it seems certain that one of the next developments was the use of a small horizontal two-stroke engine. Various airframes were built, including a simple shoulder-wing monoplane braced from an inverted-vee cabane structure, and a small Sopwith biplane. The Sopwith was damaged and was never flown.
One of the best designs was a little monoplane designed by Geoffrey de Havilland. It was powered by the first expendible aviation power unit ever made, a horizontally-opposed twin-cylinder engine designed by Granville Bradshaw of the A.B.C. company: it was related to the A.B.C. Gnat and had a power output of 35 h.p., but was designed to have a life of only two hours.
The Royal Aircraft Factory also produced a monoplane of the “Aerial Target” type; it was designed by H. P. Folland, and was powered by a 35 h.p. A.B.C. engine.
The radio-controlled aircraft were intended to be flown as guided missiles against Zeppelins and as flying bombs against ground targets. In the latter case the A.T. was to be controlled by an accompanying parent aircraft. The little machines were launched by a form of compressed-air catapult mounted on a lorry (another advanced conception), and the explosion of the warhead was simulated on test by touching off a petrol flare. These far-seeing experiments proved to be successful, yet no attempt was made to use the flying bombs operationally.
Experiments continued at Farnborough for several years after the war, and the R.A.E. produced another monoplane type, powered by the 45 h.p. Armstrong-Siddeley Ounce, in 1921. In that year a number of radio-controlled monoplanes were flown from the aircraft carrier H.M.S. Argus; they took off under their own power, using a trolley device as an undercarriage.
An even more advanced and prophetic product of Professor Low’s genius was his design for a radio-controlled rocket, which he made in 1917. He carried out several experiments with it, assisted by Commander Brock, but it saw no action. It was the true ancestor of various devices which were used in the Second World War, preceding by a quarter of a century weapons which were claimed by their inventors to be the first of their type.