Yaw damper
A yaw damper ( Y / D) is an automatic system used in aircraft that suppresses unwanted yaw , i.e. H. Turning around the vertical axis, prevented by counter-steering with the rudder .
The system was introduced in the 1960s with the first passenger jets that flew in the limit sound range and tended to oscillate around the vertical axis, so-called Dutch rolls . These were uncomfortable for the passengers and difficult to compensate for by both the pilot and the autopilot . Yaw damper They also serve the compensation of the - of passengers also perceived as unpleasant - greed roll when cornering flights autopilot.
Working method
A sensor - today usually based on a gyroscope - determines the yaw rate , i.e. H. the angular velocity at which the machine is yawing. The values determined in this way are used to calculate how the rudder must be moved in order to compensate for the yaw movement. In aircraft without fly-by-wire , the resulting control commands must be converted into mechanical rudder movements by separate elements (e.g. servo motors ).
In order to avoid impairment of flight safety due to malfunctions in the yaw damper, the maximum achievable rudder deflection can be limited, as for example with the Boeing 727, where a maximum of 5 ° deflection is possible.
The operating status of yaw dampers in the cockpit is optically signaled by a warning light that lights up when yaw dampening is activated.
On some aircraft, a warning light also lights up when the yaw damper is switched off (e.g. Boeing 737 NG).
Web links
- Yaw Dampers (English)