RAE Larynx

The Royal Aircraft Establishment Larynx (from "Long Range Gun with Lynx engine") was an early British pilotless aircraft, to be used as a guided anti-ship weapon. Started in September 1925, it was an early cruise missile guided by an autopilot.

Background

Using an unmanned aircraft full of explosives, guided by radio, had emerged during the First World war when the Royal Aircraft Factory had experimented with monoplane aircraft launched into the air from a track and guided by an autopilot, the principles of which had been developed by Professor Archibald Low. The Ruston Proctor AT (Aerial Target, a name intended to disguise its purpose), was a radio controlled biplane designed by Henry Folland, to bring down German Zeppelin airships. The aircraft proved mediocre when it was demonstrated and was dropped.

In May 1919 the Admiralty asked the Air Ministry for a target aeroplane, flown by remote-control, for anti-aircraft practice. The Royal Aircraft Establishment began tests of a small monoplane similar to the earlier Royal Aircraft Factory design. Trials began in 1922 of pilotless aeroplanes launched from ships and controlled from there or from another aircraft nearby. By 1925 the research was advanced enough for the Admiralty and Air Ministry to contemplate using such an aircraft for attacks on targets in the air and on the ground.

With no need to protect a pilot, no need for defensive measures, an unmanned bomber would cost less, fly faster, further, carry more bombs in any weather, to drop bombs or crash on a target. With no need to land, an undercarriage would not be necessary and with no problem of control at low speed, the top speed could be much higher. A weapon like this would be useful against the most elaborately defended targets or it could be a decoy, reducing the risk to manned bombers. The possibility that other countries were working along similar lines suggested that Britain also had to work on counter-measures.

Design

In 1925, the RAE was ordered to build a prototype anti-shipping missile that could fly at with of explosives, soon increased to , for , not dissimilar to the bomb-load of the new Fairey Fox. The aircraft that emerged was the Larynx, a small monoplane powered by a Armstrong Siddeley Lynx IV engine, that gave it a maximum speed of , faster than contemporary fighters. The aircraft had the autopilot that had been developed by Professor Archibald Low during the First World War.

Just before testing began the Admiralty dropped a requirement for radio control in favour of an autopilot and a device powered by the engine to measure distance flown. Wireless control needed the operator be see the Larynx but the navy wanted a flying bomb that was not reliant on another aircraft carrying the operator, since a 'shepherding' aircraft would not always be available. The cost of this was a dramatic loss of the accuracy needed to hit a ship, especially at .

Testing

Tests were conducted from 1927 to 1929 with Larynxes carrying half fuel to limit range and launched from a ramp on a ship in the Bristol Channel. The tests convinced the Air Ministry that the Larynx could be a practical weapon, with the possibility that radio remote-control would improve its accuracy. The Air Ministry became much less enthusiastic about the Admiralty requirement for a radio-controlled target because of its potential as a weapon. If the research could be kept secret, "their effect on the course of a war, coming as a surprise, might be very great and far-reaching". Advertising the existence of such a device for the navy to try to shoot down, would give away a secret weapon.

The first test took place on 20 July 1927 with the Larynx launched from a cordite-powered catapult fitted to an , the Larynx crashing into Bristol Channel. In the second test, on 1 September 1927, the Larynx was catapulted and thought to have flown before being lost. Another test took place on 15 October 1927 when a Larynx flew for at and hit from the target. In September 1928 a catapult launch from , another S-class destroyer, flew for .

Another launch from ''Thanet'' in October 1928 also flew for . In May 1929 two ground launches from Portland were tried, one flew over the target and the other hit it. Ship crews had tried to rescue aircrew from test aircraft that crashed into the sea and to keep the research into pilotless aircraft secret, testing was moved to RAF Shaibah, near Basra in Iraq, to fly Larynxes with live explosives on board. Larynx launches in August and September 1929 were disappointing, flying only , and . In October a Larynx crashed on launch and another flew .

The radio-guided target aircraft concept was allowed to drift to the bottom of the Air Ministry priority list. By the end of the 1920s a practical system using an autopilot was near ready but only if the intention was to carry as far as Paris. A range was possible but without radio control, the target would have to be extremely large. The RAE was very busy in the late 1920s, designing autopilots for manned bombers, lacked the means for research into more accurate guidance devices for pilotless aircraft and work on the Larynx was reduced to a long-term project; experiments were stopped in 1936.

Specifications

See also

* Hewitt-Sperry Automatic Airplane
* Kettering Bug
* V-1 flying bomb

Footnotes

References

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Further reading

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External links

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Remote Piloted Aerial Vehicles : The 'Aerial Target' and 'Aerial Torpedo' in Britain


a 1958 ''Flight'' article

The Mother of All Drones - Article Vintage Wings of Canada
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Cancelled military aircraft projects of the United Kingdom
Unmanned military aircraft of the United Kingdom
Guided missiles of the United Kingdom
Aircraft manufactured in the United Kingdom
Single-engined tractor aircraft
Mid-wing aircraft
Aircraft first flown in 1927