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Wessex
Westland Wessex helicopter at the Australian National Maritime Museum, Sydney, NSW, Australia
Type	Helicopter
Manufacturer	Westland
Maiden flight	1958
Introduced	1961
Retired	2003 (Royal Air Force)
Primary users	Fleet Air Arm Royal Air Force Australian Fleet Air Arm Uruguayan Air Force
Developed from	Sikorsky H-34

The Westland Wessex is a turbine-powered version of the Sikorsky S-58 "Choctaw", developed under license by Westland Aircraft, initially for the Royal Navy, but later for the Royal Air Force (RAF). The Wessex was built at Westland's factory at Yeovil in Somerset.

The name Wessex had also been used for a fixed wing light transport of 1930, a modification of the Westland IV.

Contents 1 Design and development 2 Operational history 3 Variants 3.1 Military 3.2 Civilian Models 4 Accidents and Incidents 5 Operators 5.1 Military Operators 5.2 Civil Operators 6 Specifications (Wessex HC.2) 7 References 8 External links 9 Related content

The first Wessex, a HAS.1 flew in 1958, and they entered anti-submarine duties in 1961 with the Royal Navy. Royal Navy's Fleet Air Arm anti-submarine examples (HAS Mk.1, HAS Mk.3) used the Napier Gazelle engine, a turboprop engine developed into a turboshaft. This made the Wessex the first helicopter to have a free-power turbine, where the power shaft is not physically connected to the compressor shaft.

The design was adapted in the early 1960s for the RAF, and later Royal Marines, to become a general-purpose helicopter capable of troop-carrying, air ambulance and ground support roles. In contrast with the HAS.1, it used twin Bristol Siddeley Gnome engines (not a free-power turbine). These marks (HC Mk.2, HCC Mk.4, HU Mk.5) had a single large exhaust on each side of the nose, the Gazelle-powered examples having a pair of smaller exhausts on either side.

The Wessex was first used by the RAF in 1962, and did not finally retire until January 2003, being the main transport helicopter until the introduction of the Aérospatiale Puma. The bright yellow RAF machines used for air-sea or mountain rescue duties became especially famous and saved many lives.

The Navy pressed the development of the HAS.1 into the improved HAS.3, coming into service in 1967. It saw embarked service on the County Class destroyers. The HAS Mk.3 could be identified by a dorsal radome and strake extending behind the "hump".

Wessex helicopters were also used by the Queen's Flight of the RAF to transport VIPs including members of the British Royal Family, from 1969 to 1998. Those Royal helicopters were designated HCC.4 and were essentially similar to the HC.2 but with an upgraded interior, additional navigation equipment and enhanced maintenance programmes. A later version used by the Royal Marine Commandos was the HU.5.

16 former RAF Wessex HC.2 were supplied to Uruguay. The Uruguayan Navy received 5 helicopters in 1998, with the Uruguayan Air Force taking delivery of 11 helicopters in three batches from 2000 until 2003.

(production numbers after names)

• Wessex HAS.1: 140

RN utility, anti-submarine warfare, later air-sea rescue only

• Wessex HC.2: 68

RAF Troop carrier

Can carry up to 16 troops.

• Wessex HAR.2: 6

RAF search and rescue version

• Wessex HAS.3: 46 (43 converted from HAS.1)

RN anti-submarine

Improved avionics with a radome on the rear fuselage.

• Wessex HCC.4: 2

helicopters of the Royal Flight equipped for VVIP transport

• Wessex HU.5: 101

RN service troop transporter, carried 16 Royal Marines

• Wessex HAS.31: 27

Royal Australian Navy anti-submarine warfare model.

• Wessex HAS.31B:

Updated anti-submarine warfare model for the Royal Australian Navy.

• Wessex 52: 12

military transport version for the Iraqi Air Force.

• Wessex 53: 2

Military transport version for the Ghana Air Force.

• Wessex 54: 1

Military transport version for the Brunei Air Wing.

In RN service the armament carried was:

• Pylon mounting (selection from)
  • 4 Aerospatiale SS-11
  • 2 Aerospatiale AS-12 Anti-shipping missile
  • 2 x 7.62 mm L7 GMPG machine guns.
• Fixed mounts
  • Depth charges or lightweight torpedoes.

• Wessex 60

Civilian version of the Wessex HC.2. 20 built.

• G-ATSC - Bristow Helicopters. Ditched (North Sea) March '76 - all saved
• G-ASWI - Bristow Helicopters. Crashed (North Sea) August '81 - no survivors

 Australia

• Royal Australian Navy Fleet Air Arm
  • No. 723 Squadron RAN
  • No. 725 Squadron RAN
  • No. 816 Squadron RAN
  • No. 817 Squadron RAN

 Brunei

• Brunei Air Wing

 Brazil

 Ghana

• Ghana Air Force

 Iraq

• Iraqi Air Force

 United Kingdom

• Royal Air Force
  • No. 18 Squadron RAF
  • No. 22 Squadron RAF
  • No. 28 Squadron RAF
  • No. 32 Squadron RAF
  • No. 60 Squadron RAF
  • No. 72 Squadron RAF
  • No. 78 Squadron RAF
  • No. 84 Squadron RAF
  • No. 103 Squadron RAF
  • No. 2 Flying Training School RAF
  • Queen's Flight
  • SAR Training Squadron RAF
  • Wessex Operational Conversion Flight RAF
• Fleet Air Arm
  • 700 Naval Air Squadron
  • 706 Naval Air Squadron
  • 707 Naval Air Squadron
  • 737 Naval Air Squadron
  • 771 Naval Air Squadron
  • 772 Naval Air Squadron
  • 781 Naval Air Squadron
  • 814 Naval Air Squadron
  • 815 Naval Air Squadron
  • 819 Naval Air Squadron
  • 820 Naval Air Squadron
  • 824 Naval Air Squadron
  • 826 Naval Air Squadron
  • 829 Naval Air Squadron
  • 845 Naval Air Squadron
  • 846 Naval Air Squadron
  • 847 Naval Air Squadron
  • 848 Naval Air Squadron

 Uruguay

• Uruguayan Air Force
• Uruguayan Navy

 United Kingdom

• Bristow Helicopters

General characteristics

• Crew: Two pilots (civilian type 60 Wessex cleared for single pilot operation in UK)
• Capacity: 16 troops or 8 stretchers
• Length: 65 ft 8 in (20.03 m)
• Rotor diameter: 56 ft 0 in (17.07 m)
• Height: 16 ft 2 in (4.93 m)
• Disc area: 2,463 ft² (229 m²)
• Empty weight: 8,304 lb (3,767 kg)
• Loaded weight: lb (kg)
• Max takeoff weight: 13,500 lb (6,123 kg)
• Powerplant: 2× Rolls-Royce Gnome turboshaft, 1,535 shp (1,150 kW) each

Performance

• Maximum speed: 133 mph (212 km/h)
• Range: 480 miles (km)
• Service ceiling: 10,000 ft (3,050 m)
• Rate of climb: ft/min (m/s)
• Disc loading: 5.5 lb/ft² (26.7 kg/m²)
• Power/mass: 0.11 hp/lb (0.19 kW/kg)

• Michal Ovcacik & Karel Susa, Westland Wessex: Rotary Wiings Line, 1st edition 1998, 4+ Publications, Prague Czech Republic, (in English) ISBN 80-902559-0-6.
• Patrick Allen, Wessex,1988, Airlife ISBN 1-85310-050-1.

• RAF Museum
• RAF site
• helis.com Wessex section

Comparable aircraft

Sikorsky S-58 Choctaw

Designation sequence

Westland Dragonfly - Westland Whirlwind - Westland Wessex- Westland Scout - Westland Wasp - Westland Lynx

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