Developments over recent years owe much to the efforts of companies and individuals involved in construction and flight testing of prototypes. Clockwise from top left...

Sixth-scale model assembled from DJI quadcopters and operated  by Phil Martin in Lancashire, UK.

Half-scale prototype flown by Martin Andrews in Somerset, UK and latterly by Ben Sena in California, USA.

Full-size model flown in Lancashire by Alan of Drone Images UK and latterly by Austin Laws at Snowdonia Aerospace.

66% scale-model flown by Angus Benson-Blair in Somerset, UK.

12th December 2022