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HUD Control Unit

Technical Information

Catalogue No: C1549
Category: Head-Up Display [HUD]
Object Type: Control/Data Entry
Object Name: HUD Control Unit
Part No: GAD H301-A-2
Serial No: 3?6
Manufacturer: Elliott
Division: Airborne Display [ADD]
Platform(s): Shorts Belfast
Year of Manufacture: 1968
Dimensions: Width (mm): 145
Height (mm): 85
Depth (mm): 130
Weight (g): 972
Location: Triple Shelf Unit, LH (control panels) [Main Store]

Pilots Control Unit
Type No. GAD H301-A-2
Ref No. 6TJ 326
Ser No. 326 ?


This is the Control Panel for the Belfast Pilot’s HUD system; it was not part of the Pilot’s Display Unit but remotely situated. The panel has controls as follows:
• HUD ‘On/Off’
• Rotary control for display ‘Brilliance’.
• A mode selector for ‘Take Off’, ‘Cruise’ and ‘Approach’.
• ‘Set Pressure’, QNH or QFE
• ‘Vertical Shift’ Presumably moved the display on the Combiner.
The function of the two small potentiometers is not known.

Cintel designed a HUD for the RAF’s strategic freighter, the Belfast. Design of this long-range, strategic transport aircraft began in February 1959, with the first flight in January 1964. Only ten of the originally ordered thirty Belfasts were built, all for the RAF. The Belfast HUD was integrated with the Smiths Autopilot. Although about 24 HUD units were made not many were used because of the dilemma of how the co-pilot could verify the pilot’s display. Essentially this was a variant of the Buccaneer HUD but installed across the cockpit such that the Combiner was at right-angles to the PDU body. The Combiner had an adjustable angle however to allow, for instance, for a high nose-up incidence when landing. This design probably also had an ‘Auto brilliance’ sensor which was a forward-looking photocell which operated to keep the display luminance constant despite changes in the ambient illumination. Such a system is better described as an Auto contrast function.


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