|Object Type:||Signal/Data Processor|
|Object Name:||EAP Flight Control Computer|
|Year of Manufacture:||circa 1986|
|Location:||Archive Object Store|
GEC Avionics Limited
Flight Control Computer
Hardware Mod. State 1, 2, 3
Software Iss No. 355 , 377
FRIG card not fitted
GEC Avionics Limited
Power Supply Unit.
Part No. 7502-00030
Serial No. 006
Modification Record A
EAP stands for "Experimental Aircraft Programme and was a technology demonstrator for what was to become the Eurofighter Typhoon. The sole aircraft (serial ZF534) first flew on 8 August 1986. The EAP aircraft was retired from service on 1 May 1991 and was then sent to the Aeronautical and Automotive Engineering department of Loughborough University but as of April 2012 it has been moved to the Royal Air Force Museum Cosford.
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. These 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.
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. The flight control computers pass on air data to the avionics and engine controls via EAP's two main digital data highways and additionally process motion sensor output to provide standby attitude and heading reference.
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.