Westland Wessex тікұшақтары: Британдық әскери авиация тарихы

1958 military helicopter family by Westland
the helicopter

The Westland Wessex is a British built turbine powered development of the Sikorsky H 34 (in US service known as Choctaw). It was developed and produced under licence by Westland Aircraft (later Westland Helicopters). One of the main changes from Sikorsky's H 34 was the replacement of the piston engine powerplant with a turboshaft engine. Early models were powered by a single Napier Gazelle engine, while later builds used a pair of de Havilland Gnome engines. The Wessex was initially produced for the Royal Navy (RN) and later for the Royal Air Force (RAF); a limited number of civilian aircraft were also produced, as well as some export sales. The Wessex operated as an anti submarine warfare and utility helicopter; it is perhaps best recognised for its use as a search and rescue (SAR) helicopter. The type entered operational service in 1961, and had a service life in excess of 40 years before being retired in the UK.

In 1956, an American built S 58 was shipped to Britain for Westland to use as a pattern aircraft. Initially assembled with its Wright Cyclone, it was demonstrated to the British armed services leading to a preliminary order for the Royal Navy. For British production, it was re engined with a single Napier Gazelle turboshaft engine, first flying in that configuration on 17 May 1957. The lighter (by 600 lb) Gazelle engine required some redistribution of weight. The first Westland built Wessex serial XL727, designated a Wessex HAS.1, first flew on 20 June 1958. In service, the Wessex was found to be a major improvement over the older Westland Whirlwind. The decision made by Westland to install a modern gas turbine powerplant gave the Wessex a greater load capacity, was quieter and generated less vibration, the latter quality being highly beneficial when treating casualties during flight. The Gazelle engine allowed for rapid starting and thus faster response times. The Wessex HU.5 was powered by coupled de Havilland Gnome engines, which provided nearly double the power of the original HAS.1 model and significantly extended its range. This enabled it to operate in a wider range of conditions; during the 1970s, the HU.5 also started to be used for the SAR mission. The Wessex was also used as a general purpose helicopter for the RAF, for troop carrying, air ambulance and ground support roles. The Wessex was the first of the RAF's helicopters in which instrument flying, and thus night operations, were possible. Unlike the Navy's Wessex fleet, which was largely composed of early single engine models, the RAF mandated that its Wessex helicopters should be all twin engined; this was a major factor in the RAF's decision to reject the adoption of ex FAA Wessex helicopters as the Navy migrated to the newer Sea King.

The Wessex was first used by the Royal Navy, which introduced the Wessex HAS.1 to operational service in 1961. Having been satisfied by the favourable initial performance of the Wessex but seeking to improve its avionics and equipment, the Navy soon pressed for the development of the improved HAS.3, which came into service in 1967. Operationally, younger models would be assigned to perform the key anti submarine warfare and commando transport missions, while older and less capable models would be typically be assigned to land bases for search and rescue (SAR). SAR tasked Wessex helicopters were also stationed abroad, such as at Cyprus. The Wessex often found itself being used on the battlefield as a utility transport; as well as delivering supplies and equipment, the Wessex could also transport small groups of troops. Operationally, the Wessex could lift less than the RAF's Bristol Belvedere helicopters, but was more robust and required less maintenance; thus, when the Belvedere was retired at the end of the 1960s, Wessex squadrons were often tasked with their former duties in support of the British Army on an ad hoc basis. In large scale helicopter assault operations, the type could be escorted by the RAF's Hawker Siddeley Harriers. The HC.4 variant of the Westland Sea King began to replace the Wessex in this capacity from the late 1970s onwards, although troop carrying missions would continue into the late 1990s. The Wessex's service career featured long term deployments to both Hong Kong and Northern Ireland to support internal security operations, performing transport and surveillance missions. In Northern Ireland, the use of helicopters for supply missions proved a viable alternative to vulnerable road convoys; operations in this theatre led to the employment of various defensive equipment and countermeasures against the threat posed by small arms and man portable air defense systems (MANPADS). Wessex helicopters were also used by the Queen's Flight of the RAF to transport VIPs including members of the British Royal Family; Both Prince Philip and Prince Charles were trained Wessex pilots; occasionally they would perform as flying crew members in addition to being passengers on board the VIP services. The Wessex was replaced in this role by a privately leased Sikorsky S 76 in 1998.

In 1962, an international crisis arose as Indonesia threatened confrontation over the issue of Brunei, which was not in the newly formed Federation of Malaya. By February 1964, a large number of RAF and RN helicopters, including Westland Wessex, were operating from bases in Sarawak and Sabah to assist Army and Marine detachments fighting guerilla forces infiltrated by Indonesia over its one thousand mile frontier with Malaysia. Having removed much of the anti submarine equipment to lighten the aircraft, during the campaign in Borneo the Wessex was typically operated as a transport helicopter, capable of ferrying up to 16 troops or a 4,000 pound payload of supplies directly to the front lines. Alongside the Westland Scout, the Wessex emerged as one of the main workhorses of the campaign, roughly half were operated directly from land bases and would regularly rotate with those stationed on RN vessels stationed off shore. From these operations the Commando Helicopter Force gets its nickname of the Junglies. Around 55 Westland Wessex HU.5s participated in the Falklands War, fighting in the South Atlantic in 1982. On 21 May 1982, 845 Squadron's Wessex HU.5s supported British landings on East Falkland. The type was heavily used throughout the conflict for the transportation and insertion of British special forces, including members of the Special Air Service (SAS) and the Special Boat Service (SBS). A total of nine Wessex (eight HU.5s and one HAS.3) were lost during the Falklands campaign. Two HU.5s of 845 Squadron crashed on the Fortuna Glacier in South Georgia during an attempt to extract members of the SAS during a snow storm, six of 848 Squadron's Wessex HU.5s were lost when the container ship Atlantic Conveyor was sunk and the HAS.3 aboard HMS Glamorgan was destroyed when the ship was struck by an Exocet missile.

A civilian version of the helicopter, the Wessex 60, was also manufactured and supplied to a number of civilian operators, including Bristow Helicopters, one of the biggest rotary wing operators in the world. Bristow flew them from various UK airfields and helicopter pads to support the growing North Sea Oil industry until they were withdrawn in 1982.

In April 1961, the Royal Australian Navy (RAN) announced that they had selected the Westland Wessex to become the standard service helicopter from their ships and its intention to purchase roughly 30 for anti submarine patrols, casualty evacuations, and fleet communications duties. The RAN formally accepted the first two of 27 Wessex helicopters in September 1963; 817 Squadron was the first to operate the type; the Wessex and its dunking sonar array quickly proved to be the most effective anti submarine platform as yet seen in the RAN. The Wessex was a major operational shift for the Fleet Air Arm, enabling the RAN to proceed with the conversion of the aircraft carrier HMAS Melbourne as an anti submarine platform. In typical carrier operations, a Wessex would be deployed during the launch and recovery of fixed wing aircraft as a guard helicopter; during anti submarine patrols, routine procedure was to have one Wessex airborne to actively screen the ship while a second would be fully armed and prepared for operations, such an arrangement was used during troop transport deployments by HMAS Sydney to Vietnam during the 1960s. By 1980, the Wessex was no longer being used for anti submarine operations, having been replaced by the more advanced and capable Westland Sea King in this capacity. Instead, remaining Wessex helicopters were retained to perform its secondary roles as a plane guard, search and rescue platform, and as a utility transport helicopter. The type was withdrawn from service in 1989.