01/31/2012. Remarks by Ray Watkins: "This was an 'Anglicised' version of the Sikorsky S-58 which had entered service with the USN as the HSS-1 Seabat in August 1955. The major difference between the Wessex and its US-manufactured progenitor was that it was powered by an 1,450 shp Napier Gazelle 161 free-shaft turbine instead of the 1,525 hp Wright R-1820-84 piston engine.

The Wessex was the first Royal Navy helicopter designed primarily for anti-submarine warfare and the world's first series-production helicopter powered by a turboshaft engine. The factory fresh pictured aircraft was one of the eleven pre-production aircraft which were used for flight development and evaluation trials. Eventually XM326 served with SAR units, it was scrapped at Portland, Dorset, in 1988."