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Tornado HDD Waveform Generator (space model)

Technical Information

Catalogue No: C0408
Category: Head-Down Display [HDD]
Object Type: Model
Object Name: Tornado HDD Waveform Generator (space model)
Part No: None
Serial No: None
Manufacturer: Model Construction
Division: Unknown
Platform(s): Tornado
Year of Manufacture: circa 1982
Dimensions: Width (mm): 195
Height (mm): 125
Depth (mm): 390
Weight (g): 1,770
Location: Rack RAA05 [Main Store]
Inscription(s):

Model Construction Ltd
Whitehall House, Hoo
Rochester, Kent.
Medway 250804
STD. 0634

Notes:

This is a model of the Waveform Generator for the TV Tab or EHDD system. This item bears the makers label and a Dymo label marked "229/09".

In the Tornado, the large amount of data available from the central computer and the need to provide a computing system control unit, which is useable in the demanding low level high speed flight regime led to the adoption of a multi-function electronic display system (TV Tabular Display) as the principal means of communication between the main computer and the rear seat Navigator. Two identical display units are mounted to the left and right of the Navigator’s combined radar map display in both the Tornado IDS (Interdictor Strike) and ADV (Air Defence) variants.

 The main computer controls the generation of synthetic data for these CRT displays according to the mode selected. The display units also accept video information (for example from sensors such as infra-red systems, radar or TV missiles) and can display pictorial information overlaid by the synthetically generated data. These are in effect computer terminals allowing the Navigator to program or reprogram the main computer and to display all information available in either tabular or graphic form. The navigator selects the display mode (format) and inserts or amends data by means of the keyboard provided beneath each screen. Additionally the TV mode enables the display of raster type pictures from other sensors such as infra-red systems, radar or TV missiles.

The equipment uses television raster techniques throughout because of the reduced complexity, power and cost of the display unit. The waveform generator circuits are packaged on multilayer printed circuit cards and interconnected by a multilayer motherboard. Great care has been taken to ensure efficient conduction of the heat generated to a ‘cold wall’ heat exchanger forming one side of the unit. Well-established computer thermal modeling has been used to optimise the component layout and heat sink design and to predict each individual part temperature.

The display units incorporate a number of unusual features. The first and most obvious of these concerns is the CRT which has to be both rugged and of exceptionally high brightness for viewing in a cockpit in strong sunlight conditions. AEG have developed a bi-potential lens, which, coupled with a high beam current and a high-voltage anode provides the necessary line brightness at the screen. The use of narrow band phosphor coupled with a compound chromatic filter enables a minimum specified contrast ratio to be maintained even under extreme cockpit illumination conditions equivalent to bright sunlight. Photo-sensors automatically maintain the display brightness at an acceptable level as the cockpit illumination conditions vary. To maintain a precisely rectangular picture, circuits compensate the scan waveforms for the geometric errors inherent when using a flat CRT screen.

The top row of the three tiers of push buttons on the keyboard are unusual in that they are multifunction. Depending on the mode selected, they are labelled on CRT itself by the main computer.

Marconi-Elliott Avionic Systems Limited subcontracted the design of the display units to AEG-Telefunken, but retained the waveform generator design and overall equipment control responsibilities itself.

The Tornado TVTab system underwent trials in a Buccaneer XT272 in 1980 at Warton

The Tornado TVTab display and the EHDD are both driven by a similar waveform Generator WFG; that for the TVTab is WFG1 and for the EHDD is WFG2.
The WFG uses TTL chips throughout and generates two independent video channels for raster scanned displays with the possibility to lock onto an external source. The symbology generation technique does not use a frame buffer as modern graphics cards and was patented as it was quite novel at the time. Data storage was difficult when the WFG was designed and for airborne application still used core store. So the WFG stores objects  such as circles, characters and lines, which can be scaled, and their locations are also defined. The picture is drawn by its x-y coordinates very fast and continuously and a ‘Bright-up’ signal is employed when the CRT beam is in the right place to draw the symbol.

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.

The Tornado originally came in two variants; the Interdictor Strike Version (IDS) for the German, Air Force and Navy, Italian Air Force, and the Royal Air Force, and the Air Defence Variant (ADV) for the Royal Air Force only. Marconi-Elliott Avionic Systems provided a wide range of equipment for both variants.

• Digital Autopilot Flight Director System (AFDS)in conjunction with Aeritalia, Italy
• Command Stability Augmentation System (CSAS)  in conjunction with Bodenseewerk, Germany
• Quadruplex Actuator Integrated into Fairey Hydraulics power control unit
• Stores Management System (SMS) in conjunction with Selenia, Italy
• Fuel Flowmeter System in conjunction with Teldix, Germany and OMI, Italy
• TV Tabular Display System in conjunction with AEG Telefunken, Germany
• Combined Radar and Projected Map Display (CRPMD) from Ferranti
• E-Scope Display System
• TACAN
• Triplex Transducer Unit
• Central Suppression Unit
• Engine Control Unit

By 1980 the Enhanced E-Scope Display (EESD) was under development. This was was a digital design with a frame store, rather than the analogue design and long persistence phosphor CRT of the original E-Scope Display (ESD). The EESD part number was 79-061-xx and this version was probably fitted to the majority of Tornado IDS aircraft.

RAF IDS variants were initially designated the Tornado GR1 with two variants called the Tornado GR1A and Tornado GR1B; the Tornado F3 was yet another version.

The contract covering the development and production investment for the Royal Air Force's mid-life update (MLU) for their 229 Tornado GRl and F3 aircraft was signed in April 1989. The upgrade included the following:

• Introduction of a new avionics architecture built around a 1553 databus.
• New sensors & Displays consisting of a Forward Looking Infra-red sensor, a Pilot's Multi-Function Display with digital map, wide angle HUD, Computer Symbol Generator, Video recording System and a Computer loading System.
• New Armament Control System consisting of a Stores Management System, a Weapon Interface Unit linked to a 1553 databus within a 1760 interface.
• A Night Vision Goggle compatible cockpit and the aircraft is also equipped with Forward Looking InfraRed (FLIR)
• Terrain Reference Navigation /Terrain Following Display/Terrain Following Switching & Logic Unit /Covert RadAlt.

Ferranti won the contract for the new HUD, Active Matrix Liquid Crystal Displays (AMLCD) to replace the TV Tabs, EHDD and E-scope. To support the new avionics a new Computer Signal Generator (CSG), with several times the computing capacity of the original Tornado main computer, and using the new high level ADA progamming language was procured

The Ferranti Nite-Op jettisonable NVGs were also procured under a separate contract.

In the event the MLU project stalled. In March 1993 a new Mid-Life Upgrade (MLU) project was launched and in1994 the UK signed a contract for MLU of GR1/GR1A/GR1Bs to GR4/GR4A standard.

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