This is a Notable Operational milestone.
Alan Marsh was the pilot.
This was the first post WWII British helicopter and the prototype for the Bristol 171/Sycamore type series of helicopters. The design was the responsibility of Raoul Hafner who was then the Chief Engineer for the Bristol Aircraft Company's Helicopter Division. The aircraft would become known as the Sycamore by UK operators in the armed services.
Source: "Helicopters and other Rotorcraft since 1907", Kenneth Munson, ISBN 0 7137 0610 4, Published by Blandford Press Ltd, 1973, Page 118