This is a Notable Operational milestone.
The first flight of the prototype (00-01, registration XW835) took place at the Westland facility in Yeovil, UK. The crew were Westland Chief Test Pilot Ron Gellatly, co-pilot Roy Moxam and Flight Test Engineer David Gibbings.
This was a Franco-British project, with the design led by Westland.
Source: "WG.13 Helicopter Civil Market Predicted", Aviation Week & Space Technology, May 31, 1971, pages 116-118