Westland Lynx
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 at, which remains unbroken as of January 2022.
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 UH-1 Iroquois. The design was to be powered by a pair of Bristol Siddeley BS.360 turboshaft engines. As part of the Anglo-French helicopter agreement signed in February 1967, French company Sud Aviation 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 Aérospatiale Gazelle and Puma for its armed forces. In October 1969, the French Army cancelled its requirement for the Lynx, so development of the armed variant was terminated at an early stage.The first Lynx prototype took its maiden flight on 21 March 1971. 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 ; both of these records were set by L. Roy Moxam OBE, Westland's Deputy 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 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 ; an official record with the FAI it still holds. At this speed, its lift-to-drag ratio was 2, and its BERP blade tips reached a speed of Mach 0.97.
The British Army ordered over 100 Lynx helicopters under the designation of Lynx AH.1 to perform several roles, such as transport, armed escort, anti-tank warfare, reconnaissance and evacuation missions. Deliveries of production helicopters began in 1977. 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 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.
Licensed manufacturing, Super Lynx, and Battlefield Lynx
In September 1974, the British and Egyptian governments initiated talks to establish a new Egyptian helicopter manufacturer. Out of these talks, the Arab British Helicopter Company 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.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. 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.
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. 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.
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. For shipboard stowage, both the rotor blades and tail can be folded. Lag dampers were incorporated but these are not required in flight. 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. 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. 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. 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.
Various avionics and on-board systems are integrated on the Lynx in order to perform differing mission profiles. Several operators have equipped their Lynx with BAE Systems' Seaspray surveillance radar to provide for a surface search capability, which is used in maritime patrol, search and rescue, and other mission profiles. British Army models are equipped with a Marconi Elliot automatic flight control system capable of performing automatic three axes stabilisation. The integration of both avionics and weapons systems is customised for each Lynx batch to customer specifications and requirements. Most of the installed sensors and avionics are typically integrated with the aircraft's avionics management system, from where they can be managed by either pilot; sensors such the optional nose-mounted FLIR can be set up to directly cue the weapon systems. Functions such as navigation and communications are also tied into the AMS, with information from these systems displayed to the pilots on interchangeable integrated display units in the cockpit. The Lynx is considerably easier to service and maintain than the AgustaWestland Apache.
The Lynx features a two-man cockpit for a pilot and observer sitting side by side; the British Army typically operates their fleet with a three-man crew, a door gunner being the third member. The cabin, located behind the cockpit, is accessed through a pair of large sliding doors on each side of the fuselage; it can accommodate up to ten equipped troops, depending upon seating configuration. An alternative configuration houses radio equipment in the cabin area when the aircraft is being used in the airborne command post role; the cabin can also be used to house additional fuel tanks for conducting long distance missions and ferry trips. The Lynx can perform a wide variety of mission types, including anti-submarine and anti-surface warfare, vessel replenishment, search and rescue, airborne reconnaissance, armed attack, casualty evacuation and troop transport; according to AgustaWestland, a Lynx can be converted from one mission-type to another within the space of 40 minutes.
Typical combat equipment includes stabilised roof-mounted sensors, onboard countermeasures and door guns; when being used in the anti-tank role, the Lynx is typically armed with BGM-71 TOW missiles; missiles such as the Sea Skua have been used in the maritime anti-surface role. Additional armaments that have been interchangeably used include rockets, 20 mm cannons, torpedoes, and depth charges. Those Lynx built for export have been typically outfitted with armaments and equipment customised for the end-user, such as the Mokopa air-to-surface missile used on Algeria's Lynx fleet, eight of which can be carried; studies into equipping the AGM-114 Hellfire have been performed, and air-to-air missiles could also reportedly be adopted if the capability is sought by operators. Equipped armaments can be managed and controlled inflight through the onboard stores management system. In order to counteract battlefield threats such as infrared-guided missiles, various defensive aid subsystems can be optionally installed, including warning receivers and countermeasures.
Many of the Lynx's components had been derived from earlier Westland helicopters such as the Scout and Wasp. The Lynx has been substantially upgraded since entering service in the 1970s; improvements made to in-service aircraft have typically included strengthened airframes, new avionics and engines, improved rotor blades, and additional surveillance and communications systems. Various subsystems from overseas suppliers have been incorporated into some Lynx variants; during a South Korean procurement, hulls produced in the United Kingdom were equipped with Korean-built systems, such as ISTAR, electro-optical, electronic warfare, fire-control systems, flight control actuators, and undercarriages. A glass cockpit was adopted on the Super Lynx 300, featuring fully integrated flight and mission display systems, a variety of integrated display units including head-up displays, and dual controls; AgustaWestland has commented that the new cockpit reduces aircrew workload and increases aircraft effectiveness. The head-up display installed could be replaced by a helmet-mounted sight system on customer demand.