Westland Lynx

The Westland Lynx helicopter is a versatile twin-engine military aircraft that was designed and built by Westland Helicopters at its factory in Yeovil, England. Initially developed as a utility craft for both civil and naval usage, the Lynx gained military interest, which led to the development of battlefield and naval variants. Since its operational usage in 1977, the Lynx has been adopted by over a dozen nations' armed forces and has primarily served in battlefield utility, anti-armour, search and rescue, and anti-submarine warfare roles.

The Lynx is a fully aerobatic helicopter capable of performing loops and rolls. In 1986, a modified Lynx set the current Fédération Aéronautique Internationale's official airspeed record for helicopters (category excludes compound helicopters) at 400.87 km/h (249.09 mph), which remains unbroken as of January 2022.

Several land and naval variants of the Lynx have been produced, including some major derivatives. The Westland 30 was produced as a civil utility helicopter, but it was not a commercial success, and only a few were built during the 1980s. In the 21st century, a modernized variant of the Lynx was designed as a multi-role combat helicopter, designated as the AgustaWestland Wildcat; the Wildcat is intended to replace existing Lynx helicopters.

The initial design, 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 (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 Aérospatiale Gazelle and Puma for its armed forces. However, in October 1969, the French Army cancelled its requirement for the Lynx, so the 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 321.74 km/h (199.9 mph) and set a new 100 km closed circuit record shortly afterwards, flying at 318.504 km/h (197.9 mph). 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 400.87 kilometres per hour (216.45 kn; 249.09 mph); 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, designated as Lynx AH.1 (Army Helicopter Mark 1), to perform various roles, such as transport, armed escort, anti-tank warfare (with eight TOW missiles), 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(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).