This version of the Wessex was created for use on UK SAR duties in the mid 1970s, being used to start the replacement of the Whirlwind
HAR Mk10 on 22 Squadron
, initially at RAF Manston
. All the airframes were converted from RAF Wessex HC Mk.2
s, most of the early airframes having been previously used by Support Helicopter Squadrons as used overseas by 78 Squadron at Sharjah and 103 Squadron at Tengah, Singapore as these squadrons disbanded and were withdrawn. Although very similar to the SH variant, they received the familiar all yellow RAF SAR colour scheme and were permanently configured with role equipment for SAR missions, and such important items as a wet fit floor to minimise corrosive sea water incursion. They were also the first Wessex variant to be fitted with the 300 foot cable length rescue hoist.