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Yaw Damper Computer

Technical Information

Catalogue No: C1315
Category: Flight Control
Object Type: Signal/Data Processor
Object Name: Yaw Damper Computer
Part No: 6310-A-2
Serial No: 169/68
Manufacturer: Elliott Automation
Division: Unknown
Platform(s): VC10
Year of Manufacture: 1968
Dimensions: Width (mm): 91
Height (mm): 205
Depth (mm): 449
Weight (g): 4,980
Location: Rack RAA01 [Main Store]

Yaw Damper Computer
Type No 6310-A-2
Ref No
Ser. No 169/68
[mods] 0
[luggage tag]
Date assessed 30 Oct 2013
Owner VVC10 Defence IPT


In order to enhance the basic stability of the aircraft against dutch roll each autopilot system incorporates a yaw damper which is operative when the autopilot is engaged. In the event of failure of both dampers a third completely independent (Standby) yaw damper is available which may be engaged at any time. The Standby Damper drives the upper rudder surface under conditions where the Emergency Ram-Air Turbo-alternator (ELRAT) is operating. (The VC10 had two Ram Air Turbines RATs, one for electrical power (ELRAT) and one for hydraulics (HYRAT)) .
The Yaw Damper Computer was an Elliott design (not a Bendix licenced design) and was delivered for the very first flight of the VC-10 from Weybridge as yaw damping was deemed critical.
The Component Location label shows that this unit contained the module types: SA-541; SA-532; SA-514; 6307-A-1 & 6859.

A yaw damper is a device used on many aircraft (usually jets and turboprops) to damp (reduce) the rolling and yawing oscillations known as the Dutch roll mode. It consists of yaw-rate sensors and a processor that provides a signal to an actuator connected to the rudder. The use of a yaw damper helps provide a better ride by preventing the uncomfortable yawing and rolling oscillation. On some aircraft it is mandatory for the yaw damper to be operational at all times during flight above a specified altitude.

Modern digital yaw dampers are part of an integrated digital autopilot system. They use accelerometers and rate sensors to determine the aircraft's motion. It then runs the numbers through special algorithms to determine what rudder inputs need to be made in order to damp any Dutch roll and to coordinate a turn. It then provides those rudder commands to a servo or hydraulic system which operates the rudder. The yaw damper is also known as a Stability Augmentation System.

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