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Hydraulic Actuator Demonstrator

Technical Information

Catalogue No: C0310
Category: Flight Control
Object Type: Actuator
Object Name: Hydraulic Actuator Demonstrator
Part No: 48419H1 Iss 24
Serial No: FYH111538
Manufacturer: Unknown
Division: Unknown
Platform(s): Tornado 
Year of Manufacture: Unknown
Width (mm):
Height (mm):
Depth (mm):
Weight (g):
Location: Main Object Store

Part No. 48419H1 Iss 24
Serial No. FYH111538


This later unit is probably another prototype unit. and is fitted with a 700mm cable

It was in 1950 that Elliott Bros. set up a small team to try to break into aircraft automation, In 1958 work was started at Borehamwood on a new automatic flight control system for the English Electric TSR 2, a high performance aircraft for use both for strike and reconnaissance purposes. The complete system of automatic control equipment, hydraulic power controls, simulated control surface forces, and simulated characteristics was assembled at Rochester.

The Quadruplex Actuator comprises four separately controlled electrohydraulic actuators which are individually coupled to a common output member by clutch plates rotating around the common output shaft. The Actuator is normally utilised as a position servo, separate and isolated servo-amplifiers being used for each of the four lanes to sum the position demand input and the position feedback and provide a drive for the electrohydraulic valve of each lane. The operating pressure is 3000lbf/in2

A working demonstrator built in perspex and opearted from a pneumatic air supply to illustrate the basic concept was shown at the SBAC Exhibition at Farnborough in 1963. A Quadruplex Actuator was first supplied in linear form in 1964 for the FIAT G95 VTOL rig followed by a similar set for the Dornier DO31 simulator rig. The lightweight rotary form was developed under a Ministry of Technology contract for a Failure Survival Autostabilization System.

In 1970 the company won the prime contract for development of the Command Stability Augmentation System (CSAS) and Autopilot/Flight Direction System (AFDS) for Tornado. The design of the Tornado Quadruplex Actuator was that of Stafford Ellis the most prolific inventor in this company’s history. Tornado has an advanced “fly-by-wire” control system. This entails electrically signaling the commands from the pilot’s control column to the aircraft’s flying controls and solves the problems which are associated with mechanical control systems on aircraft with advanced performance and variable wing-sweep angles. Electrical signaling also enables the control response to be supplemented electronically, so compensating for the wide variations in aircraft characteristics over its wide flight envelope.

The flying controls for Tornado comprise tailerons, rudder and spoilers and the control surface movements required in manoeuvring and stabilising the aircraft are electronically computed and electrically signalled to the power control servo units which position the taileron, rudder and spoiler control surfaces.

The taileron and rudder power control servos each embody a quadruplex electrohydraulic actuator which converts the electrically-signaled control surface demands into mechanical movements and enables the system to survive failures to an extent compatible with the electronic computing and main hydraulic power control elements in the system. Fairey Hydraulics developed the Tornado actuator under licence from Marconi Elliott Avionics and adapted the hydraulic design to suit the specific requirements of the Tornado. The quadruplex actuator was developed as an integral part of the taileron and rudder power control units which Fairey Hydraulics supplies. The Quadruplex Actuator was fitted to all variants of the Tornado.       

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 Version (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
• Triplex Transducer Unit
• Central Suppression Unit
• Engine Control Unit

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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