The Westland Lynx is a British multi-purpose twin-engined military helicopter designed and built by Westland Helicopters at its factory in Yeovil. Originally intended as a utility craft for both civil and naval usage, military interest led to the development of both battlefield and naval variants. The Lynx went into operational usage in 1977 and was later adopted by the armed forces of over a dozen nations, primarily serving in the battlefield utility, anti-armour, search and rescue and anti-submarine warfare roles.
The Lynx is a fully aerobatic helicopter with the ability to perform loops and rolls. In 1986, a specially modified Lynx set the current Fédération Aéronautique Internationale's official airspeed record for helicopters (category excludes compound helicopters) at ,"AgustaWestland G-Lynx helicopter to be recognised for maintaining world speed record since 1986." Western Gazette, 24 September 2014. (archived version) which remains unbroken as of January 2022."Event held to mark helicopter speed record being set" . BBC, 11 August 2016.
Several land and naval variants of the Lynx have been produced along with some major derivatives. The Westland 30 was produced as a civil utility helicopter; it was not a commercial success and only a small number were built during the 1980s. In the 21st century, a modernised variant of the Lynx was designed as a multi-role combat helicopter, designated as the AgustaWestland AW159 Wildcat; the Wildcat is intended to replace existing Lynx helicopters.
Development
Origins The initial design, then known as the Westland WG.13, was started in the mid-1960s as a replacement for the Westland Scout and Wasp, and a more advanced alternative to the Bell UH-1 Iroquois. The design was to be powered by a pair of Bristol Siddeley BS.360 turboshaft engines.James 1991, pp. 400–401. As part of the Anglo-French helicopter agreement signed in February 1967, French company Sud Aviation (later Aérospatiale) had a 30 per cent share of production work, Westland performing the remainder. It was intended that France would procure the Lynx for its navy and a heavily modified armed reconnaissance variant for the French Army, with the United Kingdom in return buying the Aérospatiale Gazelle and the Puma for its armed forces. In October 1969, the French Army cancelled its requirement for the Lynx,James 1991, p. 401. so development of the armed variant was terminated at an early stage.Gibbings 2009, p. 140.
The first Lynx prototype took its maiden flight on 21 March 1971.James 1991, p. 402. In 1972, a Lynx broke the world speed record over 15 and 25 km by flying at and set a new 100 km closed circuit record shortly afterwards, flying at ;Rotorcraft World Records, List of records established by the 'Lynx A.H. Mk.1' . Fédération Aéronautique Internationale (FAI). Retrieved 15 February 2009. both of these records were set by L. Roy Moxam OBE, Westland's Deputy Chief Test Pilot (later Chief Test Pilot). In 1986, the former company demonstrator Lynx, registered G-LYNX, was specially modified with Gem 60 engines and British Experimental Rotor Programme (BERP) rotor blades. On 11 August 1986 the helicopter was piloted by Trevor Egginton when it set an absolute speed record for helicopters over a 15 and 25 km course by reaching ;"Rotorcraft Absolute: Speed over a straight 15/25 km course ". Fédération Aéronautique Internationale (FAI). Note search under E-1 Helicopters and "Speed over a straight 15/25 km course". Accessed: 26 April 2014.Gibbings 2009, p. 141. an official record with the FAI it still holds. At this speed, its lift-to-drag ratio was 2,Harris, Franklin D. Rotor Performance at High Advance Ratio: Theory versus Test , p. 20. NASA/CR—2008–215370, October 2008. Accessed: 26 April 2014. and its BERP blade tips reached a speed of Mach 0.97.Hopkins, Harry. "Fastest blades in the world " Flight International, 27 December 1986. Accessed: 28 April 2014.
The British Army ordered over 100 Lynx helicopters under the designation of Lynx AH.1 (Army Helicopter Mark 1) to perform several roles, such as transport, armed escort, anti-tank warfare (with eight TOW missiles), reconnaissance and evacuation missions. Deliveries of production helicopters began in 1977.Donald, David, ed. "Westland Lynx". The Complete Encyclopedia of World Aircraft. Barnes & Nobel Books, 1997. . An improved Lynx AH.1 with Gem 41-1 or Gem 42 engines and an uprated transmission was referred to as the Lynx AH.5; only five were built for evaluation. The AH.5 led to the Lynx AH.7, which added a new tail rotor derived from the Westland 30, a reinforced airframe, improved avionics and defensive aids.
The initial naval variant of the Lynx, known as the Lynx HAS.2 in British service, or Lynx Mk.2(FN) in French service, differed from the Lynx AH.1 in being equipped with a tricycle undercarriage and a deck restraint system, folding main rotor blades, an emergency flotation system and a nose-mounted radar. An improved Lynx for the Royal Navy, the Lynx HAS.3, had Gem 42-1 Mark 204 engines, an uprated transmission, a new flotation system and an Orange Crop ESM system. The Lynx HAS.3 also received various other updates in service. A similar upgrade to the French Lynx was known as the Lynx Mk.4(FN).
Licensed manufacturing, Super Lynx, and Battlefield Lynx
In September 1974, the British and Egyptian governments initiated talks to establish a new Egyptian helicopter manufacturer.Ra'anan, Pfaltzgraff and Kemp 1978, p. 164. Out of these talks, the Arab British Helicopter Company (ABHCO) was established during the 1970s; this new organisation was accompanied by an initial arrangement to manufacture under licence the Lynx AH.1 in Helwan, Egypt. A separate agreement was formalised with Rolls-Royce to license manufacture the Lynx's Gem engines at the Helwan facility. However, this plan was ultimately aborted due to a lack of funds that resulted from the collapse of the Arab Organization for Industrialization (AOI)."Egypt rolls out Gazelle and receives Alpha Jets." Flight International, 10 December 1983. p. 1518.Ṣāyigh 1992, p. 64.
Announced in 1984, the Lynx-3 was an enhanced development, featuring a stretched fuselage, a redesigned tail boom, Gem 60-3/1 engines, a wheeled tricycle undercarriage, BERP rotor blades, and increased fuel capacity.Eden 2004, pp. 495, 497. Both Army and Naval variants were proposed; however, the project was ended in 1987 due to insufficient orders being placed. Only one Army Lynx-3 prototype was built. A development of the Lynx AH.7 with the wheeled undercarriage of the Lynx-3 was marketed by Westland as the Battlefield Lynx in the late 1980s. The prototype first flew in November 1989, and deliveries began in 1991. In British Army service this variant is designated as the Lynx AH.9."AgustaWestland Lynx, Super Lynx and Future Lynx". Jane's Helicopter Markets and Systems. Jane's Information group, 2009. "Subscription Article". Jane's, 8 July 2009.
In the early 1990s, Westland incorporated some of the technology from the Naval Lynx-3 design into a less-radical Super Lynx. This featured BERP rotor blades, the Westland 30-derived tail rotor, Gem 42 engines, a new under-nose 360-degree radar installation and an optional nose-mounted electro-optical sensor turret. Royal Navy Lynx HAS.3s upgraded to Super Lynx standard were known in service as the Lynx HMA.8, and several export customers ordered new-build or upgraded Super Lynxes. From the 1990s onwards, Westland began offering the Super Lynx 200, which was equipped with LHTEC CTS800 engines, and the Super Lynx 300, which also had a new cockpit and avionics derived from the AgustaWestland EH101. Both of these models have achieved several export sales.Barry, Douglas. "Westland develops digital Super Lynx." Flight International, 10 September 1996. p. 26. In 2002, Flight International reported that more than 40 variants of the Lynx were in service with different users, almost 400 aircraft having been built for various customers.Grey 2002, p. 85.
Future Lynx/Lynx Wildcat
The British Army and Royal Navy Lynx fleets were to be replaced to a new common advanced Lynx variant based on the Super Lynx 300, with a new tail boom, undercarriage, cockpit, avionics and sensors. Initially referred to as the Future Lynx, and later as the Lynx Wildcat, this type has since been re-designated as the AW159 Wildcat.
While having the Lynx as the origins and basis of its design, the Wildcat differs substantially. Only 5% of its components, including some main rotor gearbox parts and fuel system, remain interchangeable with previous Lynx variants.
Design
The Lynx is a multi-purpose twin-engine battlefield helicopter, of which specialised versions have been developed for both sea and land-based warfare. A distinguishing feature between early and later aircraft is the undercarriage: early Army versions of the Lynx were equipped with skids, while the Naval and later models have been outfitted with wheels, a requirement for easy ground handling on the deck of a warship. Early versions of the Lynx were powered by a pair of Rolls-Royce Gem turboshaft engines and had a four-blade rotor, mounted on a rigid titanium monobloc rotor head of the kind pioneered by the MBB BO105 a few years earlier. The innovative blade design comprised a honeycomb sandwich structure made out of composite material.Apostolo, Giorgio. "Westland Lynx". "Westland Lynx 3". The Illustrated Encyclopedia of Helicopters. New York: Bonanza Books. 1984. ."AgustaWestland Lynx, Super Lynx and Future Lynx" Jane's Helicopter Markets and Systems. Jane's Information Group, 2010. (subscription article, dated 13 April 2010). For shipboard stowage, both the rotor blades and tail can be folded. Lag dampers were incorporated but these are not required in flight (owing to the rigidity of the monobloc rotor head). The main rotor features a vibration absorption system.
The Lynx is an agile helicopter, capable of performing loops and rolls, and of attaining high speeds. The agility of the type led to its use as an aerial display aircraft, having been operated by the Blue Eagles and Black Cats helicopter display teams."British Army Air Corps Lynx Display Team 2014 Lynx AH.7 final display season." Jane's 360, 3 August 2014."Black Cats Helicopter Display Team." Royal Navy, Retrieved: 19 October 2014. The efficiency of the main rotor, as well as the overall top speed of the Lynx, was substantially improved with the adoption of BERP rotor blade technology.J. Gordon Leishman "ENAE 632 – The British Experimental Rotor Program (BERP) Blade ", University of Maryland, College Park, Retrieved 11 April 2010 During the 1990s, the hot-and-high performance of the type was considerably boosted in the later Super Lynx 200 series, at which point the type's Gem engines were replaced with the newer LHTEC T800 turboshaft engine with associated FADEC system; the Lynx can also maintain a good level of performance under moderate icing conditions.Grey 2002, p. 86. The FADEC controls eliminated the requirement for a throttle or manual speed selection switches, further simplifying flight control. Later aircraft feature automatic stabilisation equipment; functions such as auto-hover are installed on some Lynx.Grey 2002, pp. 89–90.