Yaw damper

A yaw damper (English yaw damper, Y / D) is used in aircraft automatic system that unwanted yaw, ie rotation around the vertical axis is prevented by counter-steering with the rudder.

The system was introduced in the 1960s with the first passenger jets that flew in the border area of sound and vibrations around the vertical axis, the so-called Dutch Rolls, tended. These were uncomfortable for the passengers and both pilots to be difficult to compensate for the autopilot. Yaw damper are obvious, but the compensation of the - of passengers also perceived as unpleasant - Greed roll when cornering flights autopilot.

Operation

A sensor - today usually based on a gyroscope - determines the yaw rate, that is, the angular velocity at the giert the machine. From the values ​​thus determined is calculated electronically, such as the rudder needs to be moved, to offset the yaw motion. For airplanes without Fly -by-wire, the resulting control commands must be implemented (eg servo motors) into mechanical rowing motions by separate elements.

To avoid adverse effects on flight safety due to malfunctions in yaw damper, the maximum achievable rudder deflection can be limited, such as in the Boeing 727, where a maximum of 5 ° deflection are possible.

The optical signaling of the operating state of greed dampers in the cockpit is done by a warning light that comes on when the yaw damping is active.

In some aircraft, a warning light when the yaw damper is off (eg Boeing 737 NG).