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HUD Overhead Unit (space model)

Technical Information

Catalogue No: C0805
Category: Head-Up Display [HUD]
Object Type: Model
Object Name: HUD Overhead Unit (space model)
Part No: 229-048255
Serial No: 001
Manufacturer: GEC Avionics
Division: Airborne Display [ADD]
Platform(s): Gulfstream II
Year of Manufacture: circa 1992
Dimensions:
Width (mm):
285 
Height (mm):
325 
Depth (mm):
640 
Weight (g):
5,680 
Location: Main Store
Inscription(s):

GEC Avionics Limited
HUD (plastic) Space Model
Part 229-048255
Ser 001
NSN
Code K0656

Notes:

This is a plastic space model of an Overhead HUD with an integral Combiner very similar to the Maryland HUD.

Development of a hub-and-spoke network increases the importance of keeping an airline's home runways open. Rather than wait for the US Federal Aviation Administration to upgrade the landing aids at airports, airlines in the USA in the early 90’s began to look at what could be done to their aircraft to enable them to land in low visibility.

In the early 90’s the US Federal Aviation Administration (FAA) began a flight test programme of  a synthetic vision system (SVS) to gather data for that certification. The SVS was a joint programme with the US Defence Department to develop technology enabling low visibility landings on what they called "cooperative" and "non-co-operative" runways. A Gulfstream II testbed was equipped with a HUD and both IR and MMW, to balance the advantages and disadvantages of the two sensors. The pilot was able to switch between the two sensors initially, but there were plans to blend the images later.

The most promising solution appeared to be a system to enhance the pilot's ability to see the runway in fog. An enhanced vision system (EVS) comprises a head-up display (HUD) onto which is projected an image of the runway from an infra-red (IR) sensor or millimetre-wave (MMW) radar. The enhanced image allows the pilot to recognise the runway from a greater distance and to continue the approach, rather than divert.

In a cockpit of a transport aircraft there are two general areas in which a projection unit can be installed: the glareshield or the overhead area. The overhead area is generally preferred (the C-17 was a notable exception) but installation is bounded by the structure and pilot’s head clearance. In general, the space available reduces sharply going outboard and increases going inboard. Overhead switch panels and eyebrow windows often reduce the space available. Installation of a HUD in the cockpit overhead area was generally preferred. Overhead Projection Units were developed by the Company and in 1992 a HUD was test flown at the Maryland Advanced Development Laboratory on their Gulfstream II testbed aircraft  under the "Synthetic Vision Experimental Program".A separate Electronics Unit was located in the avionics bay. Kodak supplied the mid-wave IR and Honeywell and Lear two different MMW radars.

The RAA contains a number of models of equipment and aircraft. The equipment models were used as a marketing aid and often to ensure that the production unit will fit in the space; this was particularly true for Head Up Displays. Such equipment models will have minimal or no functionality. Models might  just be used as weighted units or as cockpit lighting evaluation units. The HUD used on the YF-16 was of the correct weight and envelope but only mounted the Spin 'chute button (a feature only required for the early test flights). Many of these models were made by professional model makers from the original drawings and could be quite expensive; alternatively the real hardware would be used.

The aircraft models range from the simple small scale kits to quite large display items. The large model aircraft were often a marketing tool from places like Airbus or Boeing but may be found in Boardrooms or Reception areas wheras the small models may be given as a visitor handout. Those models made from kits have largely been brought in from home but are useful to illustrate the platform alongside the equipment. The large models will be hugely expensive.

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