Skeleton Helmet Mounted Sight

Marconi-Elliott Avionics
Skeleton HMD
Part 79-053-07
Ser
NSN
Code K0656

During 1978 and 1979 a flight trial was carried out in a Lynx Helicopter in conjunction with Westland Helicopters under an MoD contract to evaluate the practicality of a helmet display. The equipment comprised an Interface Unit, a special purpose Symbol Generator and the ‘Skeleton Helmet designed by the Flight Automation Research Laboratory. The helmet actually dates back to about 1969 and incorporates a red LED matrix array of 20 x 23 elements manufactured at the GEC Hirst Research Centre. An optical relay using a prism collimates the image and transfers it to the pilot’s right eye via a dichroic patch on the visor. The field of view was only about 5degrees. The presentation was very simple and was designed to ‘close the loop’ for using an HMD as a flight director showing radio altitude deviation from a chosen datum and heading error on a non-linear cross pointer display.
The helmet was sewn together by a number of women; Mrs Campbell, Mrs Morgan and Mrs Paternoster.
This early design has an optical combiner inset into the visor but the later systems (as in C0386) had the dichroic patch deposited on the Visor allowing it to be flight cleared.
From this early system the line can be traced to the equipment that was eventually fitted to the Jaguar. This Sight was made around 1977 or a little earlier.