Tony Peden writes: > > I understand that some new autopilots for small planes are > > tolerant of turbulence, but that most are not -- you risk > > creating excessive stresses. > > Absolutely amazing.
Not so much -- consider the problem: every time the AP sees a deviation, it will try to correct it. Once you're in moderate-to-severe turbulence, it's going to see a lot of deviations in rapid succession and will be deflecting the control surfaces back and forth very quickly, where a human pilot would know to relax tolerances and ride the waves. I remember a theory that the rudder oscillations that brought down AA 587 in November 2001 were AP-induced, in response to the wake turbulence from the preceeding JAL 747 -- I don't know if that theory is still credible, though. The initial investigation team reported that the rudder-trim jack screw was set for a 10-degree deflection (suggesting AP control), but later investigators said it was in the neutral position (suggesting pilot control with the rudder pedals). >From what I understand, one of the other joys of a multi-axis autopilot is the risk of runway elevator trim. On any size of plane with electric trim (required for vertical AP control), you have to know where that circuit breaker is and be ready to grab it fast. Also, when the AP sounds an alarm and disengages, it can leave you in some pretty bizarre trim situations that require a lot of control pressure to correct. All the best, David -- David Megginson, [EMAIL PROTECTED], http://www.megginson.com/ _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
