I never claimed to have personal experience of parallel yaw dampers - just quoting what I have read in 1960s era books by authoritative test pilots (eg DP Davies) to answer Genghis Khan's question which has remained unanswered until now.
What has it got to do with an outboard engine failure? My understanding of parallel yaw dampers is that they faithfully transmitted to the pedals the actual rudder deflection required to dampen dutch roll - which was fine during the cruise where the period of dutch roll was typically resonant with pilot reaction time leading to pilot induced oscillation, but was somewhat disconcerting during other flight regimes because it would be out of phase with what the pilot sensed. However, in the case of an outboard engine failure at take off, both pilot and yaw damper would typically have the same pedal input - so there would be no conflict. The yaw damper was thus turned off during take off and landing in case it lead to unneccesary feeback to the pilot.
And why would the pedal input on outboard engine failure be any higher with yaw damper in operation than without yaw damper? I don't understand your point at all.
But as I say, I am only quoting from memory from books I have read and I have never flown a plane with parallel yaw dampers so I am sure you may like to explain in detail your point.
Last edited by richatom; 13th March 2008 at 20:22.