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.
Design and development
Background
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.[1] For British production, it was re-engined with a single
Napier Gazelleturboshaft engine, first flying in that configuration on 17 May 1957.[2] The lighter (by 600 lb) Gazelle engine required some redistribution of weight. The first Westland-built Wessex
serialXL727,
designated a Wessex HAS.1, first flew on 20 June 1958.[2] The first production Wessex HAS1 were delivered to Royal Navy's
Fleet Air Arm (FAA) in early 1960; the Wessex was the first helicopter operated by the FAA to be purpose-designed from scratch as an anti-submarine platform.[3]
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.[3] The Wessex could also operate in a wide range of weather conditions as well as at night, partly due to its use of an automatic pilot. These same qualities that made the Wessex well-suited to the anti-submarine role also lent themselves to the
search and rescue (SAR) mission, which the type would become heavily used for.[3]
Further development
An improved variant, the Wessex HAS.3, succeeded the HAS.1 in the anti-submarine role; it had a more capable radar and better avionics, greater engine power, improved navigational features and a more advanced weapon system; the original HAS.1 were re-tasked for SAR duties.[3] A commando assault variant, the Wessex HU.5, was also developed as a battlefield transportation helicopter; it was deployed on the navy's
amphibious assault ships, such as the
commando carrierHMS Albion, and used to transport
Royal Marines.[4] 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.[3]
As an anti-submarine helicopter, the Wessex could be either equipped with a dipping
sonar to detect and track submarines or be armed with either
depth charges or
torpedoes; a single Wessex could not search for and attack submarines as this was beyond its carrying capability. It was this limitation that soon led the Royal Navy to search for a more capable helicopter that could provide this capability. This ultimately resulted in Westland proceeding with the adaptation and production of another Sikorsky-designed helicopter in the form of the
Westland Sea King.[5][6]
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.[7] 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.[8]
Operational history
United Kingdom
Overview
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).[3]
The RAF became an operator of the Wessex in 1962; those helicopters used for air-sea or mountain rescue duties helped make the Wessex a particularly well known aircraft of the service and contributed to the saving of many lives during its time in service. As one of the RAF's standing duties, multiple Wessex helicopters were permanently kept on standby to respond to an emergency located anywhere within 40 miles of the British coastline within 15 minutes during daytime, at night hours this response time was decreased to 60 minutes.[9] SAR-tasked Wessex helicopters were also stationed abroad, such as at
Cyprus.[10] The qualities of the Wessex were described as being "ideal for mountain flying".[11]
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.[12] 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.[13] In large-scale helicopter assault operations, the type could be escorted by the RAF's
Hawker Siddeley Harriers.[14] 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.[15]
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.[16] 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).[17]
Wessex helicopters were also used by the
Queen's Flight of the RAF to transport
VIPs including members of the
British Royal Family;[10] in this role, the helicopters were designated HCC.4 and were essentially similar to the HC.2, differences included an upgraded interior, additional navigation equipment and enhanced maintenance programmes.[18] 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.[19] The Wessex was replaced in this role by a privately leased
Sikorsky S-76 in 1998.[20]
Wartime operations
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.[21] 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.[22][23] From these operations the
Commando Helicopter Force gets its nickname of the Junglies.[24]
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).[10] A total of nine Wessex (eight HU.5s and one HAS.3) were lost during the Falklands campaign.[25] 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[26] and the HAS.3 aboard
HMS Glamorgan was destroyed when the ship was struck by an
Exocet missile.[27]
Civilian operations
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.[28] Bristow flew them from various UK airfields and helicopter pads to support the growing
North Sea Oil industry until they were withdrawn in 1982.
Australia
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.[29] The RAN formally accepted the first two of 27 Wessex helicopters in September 1963;[30] 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.[31][32]
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.[33] 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.[32] Performing search and rescue sorties became another valued role of the type; in 1974, multiple Wessex helicopters participated in the relief effort in
Darwin in the aftermath of
Cyclone Tracy.[32]
While the Wessex proved to be too large to reasonably operate from most of the RAN's destroyers, it was found to be well suited as a troop-transport helicopter from heavy landing ships and larger vessels.[34] 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.[32][35] The type was withdrawn from service in 1989.[36]
Variants
Wessex HAS.1
RN utility, anti-submarine warfare, later air-sea rescue only, 140 built, some later converted to HAS.3.
Wessex HC.2
RAF Troop carrier for up to 16 troops, One prototype converted from HAS1 and 73 built.
Wessex HAR.2
RAF search and rescue conversions.
Wessex HAS.3
RN anti-submarine version with improved avionics with a radome on the rear fuselage, 3 new-build development aircraft and 43 converted from HAS.1
Crew: Two pilots (civilian type 60 Wessex cleared for single pilot operation[100])
Capacity: 16 troops or 8 stretchers
Length: 65 ft 10 in (20.07 m)
Height: 15 ft 10 in (4.83 m)
Empty weight: 8,340 lb (3,783 kg)
Gross weight: 13,500 lb (6,123 kg)
Powerplant: 2 ×
de Havilland Gnome H.1200 Mk.110/111
turboshaft, 1,350 shp (1,010 kW) each (limited to 1,550 shp (1,160 kW) total[2])
Main rotor diameter: 56 ft 0 in (17.07 m)
Main rotor area: 2,463 sq ft (228.8 m2)
Performance
Maximum speed: 132 mph (212 km/h, 115 kn)
Cruise speed: 122 mph (196 km/h, 106 kn)
Range: 310 mi (500 km, 270 nmi) with standard fuel
Service ceiling: 12,000 ft (3,700 m)
Rate of climb: 1,650 ft/min (8.4 m/s)
Notable appearances in film
Wessexes portrayed the visually similar
CH-34 Choctaws in
Stanley Kubrick's 1987 film Full Metal Jacket.[101] The helicopters used were Wessex 60s, a civilian version of the Wessex HC.2. These are powered by the coupled-twin
de Havilland Gnome[102] with a distinctive long nose and single large turbine exhaust on each side, distinguishing them from the CH-34. XT761 was featured in season 4 of
The Crown depicting Tom Byrne as
Prince Andrew visiting the Queen.[citation needed]