Why 2 Yaw Dampers?

[Lookin for Better]

For all of you studying for the Cathay Interview, anyone got a good answer for this question? Seems to be a common question on the interview. Besides Redundency

[Macgyver]

In the book Handling the Big Jets, it mentions a/c with bad oscillatory stability characteristics will have 2 YDs, where 1 is a backup in case the other fails.

[Lookin for Better]

besides redundancy?

[Kenny]

Next time you're sitting on Sierra waiting in the conga line to depart 27L, have a look in your MEL book at the dispatchability of the aircraft with one YD out of action as opposed to both.

Therin lies your answer...........