Patrick Allen describes the
The Commando Sea King Mk.6CR was introduced into service in early October 2004 by the UK Joint Helicopter Command (JHC) to help provide the Commando Helicopter Force (CHF) with additional operational aircraft as the Commando Sea King Mk.4 fleet begins a major avionics upgrade programme. This will allow the current fleet of 33 Commando Sea King Mk.4 utility/troop transport helicopters to undergo a two-stage upgrade programme to see them operational until around 2012.
The first stage of the programme will take approximately one year and provide a Bowman secure communications suite which will involve a new aircraft electrical loom and the fitting of an enhanced avionics suite comprising an ‘Elmer’ secure speech radio, Mode ‘C’ identification friend or foe and Sky Guardian 2000 radar warning receiver (RWR) to replace the current Prophet 2 system.
The second stage upgrade will see the addition of a cockpit voice recorder, health and usage monitoring system and a ‘zapper’ to help reduce spurious main gearbox ‘chip’ detection incidents. At some stage during the programme, the aircraft will also be fitted with a directional infra-red countermeasures system in place of the current infra-red jammers.
To help maintain CHF’s combat readiness during the upgrade programme, six anti-submarine warfare (ASW), Westland Sea King Mk.6 airframes,that had been in long-term storage, were earmarked for use by the CHF and converted to the Commando role.
Of these six airframes, one will not be converted and will remain as a spare airframe. Five have undergone a full airframe overhaul and have been converted to the Mk.6CR to provide three operational aircraft for an initial five-year period, with one aircraft in sustainment and one as a front-line spare.
The design work for the Mk.6CR conversion programme was initially undertaken by the Royal Navy’s Mobile Aircraft Support Unit (MASU) which provided a trial installation. Once this was approved, the conversion work was undertaken by the Ministry of Defence’s Defence Aviation Repair Agency (DARA). The first aircraft, XV922/’ZA’ was the trials aircraft and was sent to QinetiQ at Boscombe Down to obtain its operational release before returning to RNAS Yeovilton.
The Mk.6CR conversion entailed stripping out all the anti-submarine warfare (ASW) equipment including the sonar, radar and the fitting of troop seats. The sponson undercarriage remained, but with the landing gear welded in the down position. New avionics included a tactical air navigation system (TANS) and three radios: - two AD3400 V/UHF and VTAC radios plus a ‘TALON’ Have-Quick secure speech radio with digitally tuned aerial.
The cockpit has also been equipped with full night vision goggle (NVG) lighting along with external NVG formation lights and twin ‘Bright Star’ infra-red lights. Aircraft survivability equipment includes armoured crew seats, ALQ 157 infra-red jammer and a GPMG machine gun mount in the cabin door. The nose-mounted battery has been upgraded and combined with a battery-pack installed in the rear cabin to enable engine starts in field conditions. A rear console has been fitted in the cabin to provide the crewman with a TANS and HF and V/UHF/VTAC radios. The aircraft has also received the standard Commando Sea King HC Mk.4 paint scheme and a troop step for the cargo door.
With a basic weight of 13,500lbs, the Sea King Mk.6CR is 1,000lbs lighter than the standard Commando Sea King HC Mk.4, and is equipped with 12 troop seats, rescue-hoist and a semi-automatic cargo release unit, a wire and cable system bolted onto the helicopter to fit a load-hook for under-slung load lifting. The all-up weight is the same as the Mk.4 variant at 21,000lbs, which can be increased to 21,400lbs when operationally necessary.
In October 2004 a pair of Commando Sea King HAS Mk.6CR variants of the Westland Sea King, were deployed to Bosnia operating with the CHF No 846 Naval Air Squadron, who are home based at RNAS Yeovilton, Somerset in support of Operation Oculus.
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