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Concorde Warning & Landing Display

Technical Information

Catalogue No: C0572
Category: Flight Control
Object Type: Indicator/Instrument
Object Name: Concorde Warning & Landing Display
Part No: 79-010-03
Serial No: 014
Manufacturer: Elliott/SFENA Consortium
Division: Flight Controls [FCD]
Platform(s): Concorde
Year of Manufacture: 1965
Dimensions: Width (mm): 184
Height (mm): 38
Depth (mm): 112
Weight (g): 508
Location: Triple Shelf Unit, Mid (control panels) [Main Store]

Elliott SFENA Consortium Design
Unit: Warning & Landing Display
Type 79-010-03
Ser. No. 014
Code 66 266 774 00 Elliott
Modifications 0


The Warning and Landing Display is located at the top of the left-hand side of the pilot’s instrument panel just above the Air Speed Indicator and Attitude Display Indicator. The pilot’s instruments for the most part were duplicated on the Co-pilots side however to add redundancy some of the instruments were supplied information by separate systems.
The left-hand illuminated push-button ‘AP’ will flash red if the Autopilot system is no longer functioning correctly. Pushing the button resets the system. The adjacent ‘AT’ illuminated push-button will flash red if the Autothrottle system is no longer functioning correctly. Pushing the button resets the system.
The central panel has the Aircraft Deviation Lights which are associated with the autopilot and/or flight director in the approach modes. The lighted strips around the aircraft symbol indicate the deviation from Localiser or Glide Slope. It would be expected that the AFCS would automatically correct for this deviation and these would go out.
LAND 2 and LAND 3 light will be green if the AFCS is working, and available to support an automatic landing in CAT2 or CAT3 conditions.
The DH – Decision height warning will light when the aircraft is flying under the height set into the associated radio altimeter. There is also a Test button to test all the warning lamps in this panel.

Early in 1963 joint proposals were made, together with Bendix, for a flight control system for a proposed supersonic civil transport. This was the forerunner of what became the 'Concorde'. When Anglo-French agreement was reached for joint development of the 'Concorde', a formal agreement was made and Elliotts led a consortium with SFENA and Bendix.  The Automatic Flight Control System included five systems, Automatic Pilot, Flight Director and Take-Off Director Computers, Automatic Throttle, Pitch axis Trim and Three Axis Autostabilisation.

Concorde was controlled in pitch and roll by Elevons and in yaw by Rudders. Each control surface is operated by a Power Flying Control Unit (PFCU).

The three Elevons, on each side of the aircraft, were in two groups; the outer and middle Elevons because their deflection angles were always synchronised, and the inner Elevons because their deflection angles in the roll axis are less than that of the outer and middle Elevons.

Conventional flight deck controls actuated three signal channels; two electrical and one mechanical.

Each electrical flying control channel was supplied from its own inverter which operated at a different frequency from the main aircraft system. On both electrical channels the pilot control movements generated, by means of synchro transmitters called resolvers, electrical signals that directly controlled the PFC servos. Each flight control group, (middle and outer elevons, inner elevons, and rudders), operated independently through its own resolvers, which also provided the pitch and roll mixing for the elevons.

The Mechanical channel also transmitted pilot control movements to the PFC servos but was unclutched at the servos when either of the electrical channels was operating.

Three control signals; two electrical and one Mechanical, were therefore available at the PFC servos, but only one was activated at any one time by the monitoring system that monitored the operation of the control surfaces by groups.

On the Mechanical channel of each flight control axis, pilot control movements were transmitted to the PFC servos by linkages and cables through a Relay Jack that compensated for linkage inertia.

Pitch and roll inputs were mixed by a mechanical mixing unit downstream of the pitch and roll relay jacks.

The monitoring system monitored:

Flight control inverters
Hydraulic systems pressure to the flight controls
Operation of the servo controls
Operation of the electrical control channels
The monitoring system automatically rejected a flight control channel suffering a failure in these systems and changed to the next available channel.

Concorde also had an Auto-Stabilisation system which improved the natural stability of the aircraft. It minimises the effect of turbulence and reduced the resulting flight path disturbance following an engine failure. The system comprised two separate channels for each of the control axis: Pitch, Roll, and Yaw. The Auto-Stabilisation system generated signals in Pitch Roll and Yaw as a function of aircraft rate of movement and Mach number from the Air Data Computer.

The Artificial Feel system comprised two separate channels for each control axis, Pitch, Roll and Yaw. Artificial feel is provided on each control axis. Pitch, Roll and Yaw, by a spring rod that increased the control stiffness with increasing control deflection, supplemented by dual control jacks that change the stiffness as a function of speed at speeds above approach speed.

Conventional trim was provided in Roll, Yaw and Pitch. The trim cancelled the load of the Artificial Feel by changing the feel datum, and consequently the neutral position of the flight controls.

An electric trim system was provided only in Pitch, and comprised two separate but identical channels. The electric trim could be controlled either directly by the pilot using the Pitch Trim selector on each control column or independently of the pilot in auto trim when either autopilot was engaged or for automatic pitch stability correction. As part of the Trim system Concorde had Automatic Pitch Stability Correction.

Concorde had an Anti-Stall system which operated (when engaged) at speeds below 270 knots from about 10 seconds after lift-off. At high angle of attack conditions the anti-stall system augmented the basic pitch Auto-Stabilisation with a Super Stabilisation function, and created an unmistakable warning at the approach to very high angles of attack through the Artificial Feel and a Stick Shaker.

Finally there was an Emergency Flight Control System which provided an additional flight control capability in Pitch and Roll axes in the event of a control jam between the control column and the Relay Jacks.

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