The yawdampener will not move the rudder pedals in normal operations. However in the event of an engine failure, autopilot engaged and slats not up, yaw dampener will provide an extra 5 degrees of travel ontop of the authority of the autopilot rudder channel for a total of 15 degrees of movement.
Normally the yawdampener does what it wants when it wants without moving the pedals. Furthermore it is not subject to limitation by the rudder load limiter. The load limiter strictly blocks rudder pedal travel (though apparently according to airbus at the NTSB hearing it can be overridden by stepping firmly on it, though that is no where in the manual.)
Cwatter
The crew was flying the JFK departure, Bridge climb. They took off on ruway 13L and immediately make a sharp turn to a heading of about 230 degrees to fly to the bridge NDB (about 2 miles from the airport) After crossing over the NDB they are to fly a heading (not track) of 220 degrees, expect radar vectors.... Usually by the time you reach Bridge NDB ATC orders you to pick up a heading of 130 or so...
It looks like they were in the turn when they hit the first wake which served to level the aircraft. They were rolling back into the turn when they hit the second wake further rolling the aircraft in the direction of the turn.
One of those unmarked design "Features" of the A300-605r is that if you roll past 65 degrees of bank all the flight displays go into reset (note it did not happen that we are aware of this time, but has in previous upsets) and go blank for 5 secs. This was found out by a crew that had an upset in the carribean. Needless to say that made recovery much more difficult combined with the unexpected suprise at the time. I would do anything to keep the aircraft from rolling away from me, because without instruments its just that much harder to recover.
Furthermore, before anyone considers Sten heavy footed, look at the reconstruction video I put up in the last post. Now look at the rudder inputs that sten used rolling down the runway. Take a grease pencil and mark your monitor where the limits of the inputs are rolling down the runway. You will see that Sten used no more than 1/3rd or so of the available rudder travel to keep the plane rolling down the runway. When the wake encounter happened, those same inputs are now FULL TRAVEL inputs. There is no way in 40 seconds or so he could adjust to the increased sensitivity, nor could Captain States have known that he was banging off the stops. It would have looked like a moderate input. Also, with the rudder pedal movement stopped at 1.3 inches or so 15 minutes after you just did the control check with 4 inches of travel, and the aircraft not behaving as you expect it to, you might feel you have a jammed control, causing you to step harder. Well unknown to EVERYONE except the airbus engineer, if you step harder you will overpower the rudder load limiter and full travel will now be available to you at high speed. How is that a safe or smart design?
The excuse that things get lost in the manuals in translation is simply inexcusable. The language of aviation is English. If you can't produce a manual in English, you certainly shouldn't be building commercial jets for sale outside of France. The same goes for the airbus engineers at the hearing that everytime a difficult question came up simply said, I don't understand the question. IF they are unable to locate a translator that can translate the question, than how can we be sure they actually met certification standards? That excuse alone ought to cost em all of their certifications.
Cheers
Wino
Last edited by Wino; 12th Nov 2002 at 21:52.