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EAP Actuator Drive Unit (ADU)

Technical Information

Catalogue No: C0261
Category: Flight Control
Object Type: Signal/Data Processor
Object Name: EAP Actuator Drive Unit (ADU)
Part No: 2-846.10-00-00-00-000
Serial No: 007
Manufacturer: Bodenseewerk/GEC Avionics
Division: Unknown
Platform(s): EAP
Year of Manufacture: 1987
Dimensions: Width (mm): 240
Height (mm): 89
Depth (mm): 300
Weight (g): 7,360
Location: Rack RAA01 [Main Store]

Vers. Nr. Actuator Drive Unit
Bodenseewerk Gerätetechnik GmbH
Code: D0078
TKz. 2-846.10-00-00-00-000
Spec. Nr. SP-B-27-B-203
Werk Nr. 007
Datum 01.87
Mod. A
GEC Avionics Ltd
Part 7501-00028
Ser 008
Code K0656


This item is an ADU Actuator Drive Unit which has a removable Power Supply hence the combined name. It was made for the Experimental Aircraft Programme (a development aircraft in the Typhoon programme) in around 1982. It was designed by Nick Belcher and manufactured for EAP by Bodenseewerk Geratetechnik GmbH. This unit was a remote actuator drive for the rear surfaces of EAP Serial data input outputs to L/R Inboard flaperons, L/R Outboard flaperon and rudder.

There were four units on the aircraft and they had to operate in a very extreme environment in an ambient of 95°C mounted under the airbrake and over the jet pipe.

The Actuator Drive Unit contains a Power Supply Unit manufactured by GEC Avionics Ltd.

EAP's quadruplex-redundant digital flight control system is a development of that in the active control technology (ACT) Jaguar FBW test bed, the first digital fly-by-wire aircraft to fly without mechanical backup controls. The system has to withstand two critical failures. EAP has four identical flight control computers with no fewer than 13 control surfaces, the flight control computers will operate at more than three times the speed of Jaguar's. The Flight Control Computers house the flight resident software which stabilises the aircraft artificially then enables the pilot to fly it. In addition they house software for failure management, reversion logic, and built-in test.The Flight Control Computers are linked to EAP's two dual-redundant 1553B multiplex digital databuses.  The avionics databus links the cockpit with the Ferranti FIN1070 inertial navigation system, Racal RA800 audio management system, GEC Avionics AD2780 Tacan, the flight control system, and the utility services management system (USMS). In addition, the Flight Control Computers process motion sensor information to provide data for the standby attitude and heading reversionary instruments.

Also included in the flight control system are two digital air data computers, four aircraft motion sensor units (AMSUs), and four actuator drive units (ADUs). While the foreplane, intake varicowl, and wing leading-edge flaps are driven directly from the flight control computers, the flaperons and rudder are driven from the aft-mounted ADUs which are connected to the computers by serial digital databus.
The air data and motion sensors are also connected to the computers along two dual redundant 1553B multiplex digital databuses. The AMSUs consolidate roll, pitch, and yaw rate sensors in single boxes.

GEC Avionics is responsible for EAP's flight control system, supplying the four flight control and two air data computers, while Bodenseewerk supplies the four actuator drive units, and Litef the four aircraft motion sensor units.
The Company, in common with other suppliers, made equipment for the EAP at their own cost in anticipation of orders for the Typhoon. Around 6 to 8 sets of equipment were made and all were put through the full evaluation/qualification tests.


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