Control Unit

Technical Information

Catalogue No: C0210
Category: Flight Control
Object Type: Control/Data Entry
Object Name: Control Unit
Part No: 21-007-03
Serial No: 01164
Manufacturer: Bodenseewerk/GEC Avionics
Division: Unknown
Platform(s): Tornado 
Year of Manufacture:
Width (mm):
Height (mm):
Depth (mm):
Weight (g):
Location: Archive Object Store

Control Unit
Type No. 21-007-03
Serial No. 01164
Spec No. SP-P-41600
Ident No.
NATO Stock No.
Modification Record A
Manufactured by GEC Avionics Limited


The command stability augmentation system: (CSAS) is by its very nature one of the most complex systems on Tornado. Hardly detectable in the cockpit, the CSAS keeps the ride comfortable at all speeds and altitudes, and makes the aircraft controllable throughout the flight envelope.It is a “fly-by-wire” system with autostabilisation, the pilot’s control demands being signalled and augmented electrically to maintain good handling qualities over the wide flight envelope. In the pitch axis, the fly-by-wire system has mechanical reversion. The system is triplicated and includes triplex computing, triplex rate gyros, triplex position sensors and a triplex accelerometer, with quadruplex outputs driving quadruplex electrohydraulic actuators. These “fly-by-wire” actuators were originally designed by Marconi-Elliott Avionic Systems Limited and have now been integrated by Fairey Hydraulic into the aircraft’s main hydraulic power control units.
The CSAS electronics is packaged in two units, the pitch computing circuitry being housed in a single computer and the roll, yaw and spoiler circuitry in a similar computer.
The system uses very high-precision analogue circuitry to provide accurately- matched control lanes, and a unique voter monitor design which reduces transient effects, due to system failures, to a low level and is so designed also that nuisance warnings are rare.
Marconi-Elliott Avionic Systems Limited has design leadership on the CSAS programme, but shared the production with Bodenseewerk Geratetechnik.
The system was designed to Specification SP-P-41600.

This unit is the CSAS Control Unit which provides a number of indications of the state of the system by means of amber and red lamps behind legends such as ‘Air Data’, Roll MD, Pitch MD, Yaw Damp, P/R Lin, and Rudder’. The ‘Spoilers’ legends indicate with Red lamps the failure of Inboard or Outboard Spoilers. The ‘Engage’ indicators show slightly differently with a green lamp indicating CSAS Ready and a Red lamp indicating that CSAS engagement is not possible. An emergency trim system can be used by lifting the emergency trim guards on the CSAS control panel

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