RAE Larynx
Early British pilotless anti-ship missile with autopilot guidance.
The Royal Aircraft Establishment Larynx, whose name stood for "Long Range Gun with Lynx engine," was an early British unmanned aircraft designed to attack ships. Work began in September 1925, and it is regarded as an early cruise missile, steered by an autopilot.
The idea of using an unmanned, explosive-filled aircraft guided by radio had first emerged during the First World War. The Royal Aircraft Factory had previously experimented with monoplane aircraft launched from a track and controlled by an autopilot, a concept developed by Professor Archibald Low. Another early attempt, the Ruston Proctor AT (Aerial Target, a deliberately misleading name), was a radio-controlled biplane designed by Henry Folland to target German Zeppelins, but it performed poorly in demonstrations and was abandoned.
In May 1919, the Admiralty requested a remotely controlled target aircraft for anti-aircraft practice. The Royal Aircraft Establishment began testing a small monoplane similar to the earlier Royal Aircraft Factory design. Trials of pilotless aircraft launched from ships and controlled by wireless from the ship or a nearby aircraft started in 1922. By 1925, research had progressed enough for the Admiralty and Air Ministry to consider using such aircraft for attacks on both air and ground targets.
An unmanned bomber offered several advantages: no need for a pilot, defensive measures, or an undercarriage; it could be faster, fly farther, and carry more bombs in any weather, either dropping them or crashing into the target. With no need to manage low-speed control, maximum speed could be much higher. Such a weapon would be useful against heavily defended targets or as a decoy to protect manned bombers. The possibility that other nations were developing similar technology also pushed Britain to work on countermeasures.
In 1925, the RAE was ordered to build a prototype anti-ship missile capable of flying at 190 mph with 100 lb of explosives—soon increased to 200 lb—for a range of 200 to 300 miles, a bomb load similar to that of the new Fairey Fox. The resulting aircraft, the Larynx, was a small monoplane powered by a 200 hp Armstrong Siddeley Lynx IV engine, giving it a top speed of 200 mph, faster than contemporary fighters. It used the autopilot developed by Professor Archibald Low during the First World War.
- First flight
- 20 July 1927
- Engine
- 200 hp Armstrong Siddeley Lynx IV
- Maximum speed
- 200 mph
- Warhead
- 200 lb of explosives
- Range
- 200 to 300 mi
- Manufacturer
- Royal Aircraft Establishment
- Primary user
- Royal Navy (Admiralty)
Lore & Background
The Larynx emerged from post-World War I experiments with unmanned aircraft. The Admiralty and Air Ministry had explored pilotless aircraft for target practice and attack roles. By 1925, research had advanced enough to order a prototype anti-shipping missile capable of 190 mph with 100 lb of explosives, later increased to 200 lb for 200 to 300 miles. The aircraft was a small monoplane powered by a 200 hp Armstrong Siddeley Lynx IV engine, giving it a maximum speed of 200 mph, faster than contemporary fighters. It used an autopilot developed by Professor Archibald Low during the First World War.
Testing began in 1927 from a cordite-powered catapult on a ship in the Bristol Channel. The first test on 20 July 1927 ended with the Larynx crashing into the channel. A second test on 1 September 1927 flew an estimated 100 miles before being lost. On 15 October 1927, a Larynx flew 112 miles at 193 mph and hit 5 miles from the target. Further launches from destroyers and ground launches at Portland occurred through 1929. To maintain secrecy, testing moved to RAF Shaibah near Basra, Iraq, where live explosives were used. Launches there in August and September 1929 were disappointing, with ranges of only 27, 60, and 32 miles. A final launch in October 1929 crashed on launch, and another flew 22 miles.
Reader's Guide
The Larynx represented an early attempt to create a practical cruise missile, but its development was constrained by the limitations of contemporary guidance technology. The Admiralty initially dropped a requirement for radio control in favor of an autopilot and a distance-measuring device, because wireless control required an operator to see the missile, and a 'shepherding' aircraft would not always be available. This sacrifice of accuracy made hitting a ship at 300 miles extremely difficult. The Air Ministry saw potential in the weapon but became reluctant to advertise its existence by using it as a radio-controlled target for the navy, fearing that revealing the secret would undermine its surprise value. By the late 1920s, a practical autopilot system was nearly ready for a 200 lb warhead to reach Paris, but a 300-mile range without radio control required an extremely large target. The Royal Aircraft Establishment was busy designing autopilots for manned bombers and lacked resources for more accurate guidance devices. Work on the Larynx was reduced to a long-term project, and experiments were stopped in 1936.
Did You Know?
- Its autopilot was based on principles developed by Professor Archibald Low during the First World War.
- Testing was moved to RAF Shaibah near Basra, Iraq, to keep the research secret.
More in Unmanned Aerial Vehicles by Country, Part 5 1-24
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced