Autopilot Rudder Authority on 767
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Autopilot Rudder Authority on 767
Looked in the Boeing 767 Maintenance Manual, but I can't seem to find any value for autopilot rudder authority when Autoland is engaged (and airplane below 1500').
The autopilots control the rudder during autoland with 3 "Directional Autopilot Servos" (DAS's).... which are connected to the rudder Power Control Actuators.
Although the BMM mentions servo synchronization with rudder position up to +/- 25 degrees, it doesn't appear to specify the DAS's authority after engagement.
The Yaw Damper Authority is only 6 degrees left or right, but I would expect the autopilot to have more than this.
Thanks.
Rgds.
Q.
P.S. Failing that, do you have any values for the 747-400 :-)
The autopilots control the rudder during autoland with 3 "Directional Autopilot Servos" (DAS's).... which are connected to the rudder Power Control Actuators.
Although the BMM mentions servo synchronization with rudder position up to +/- 25 degrees, it doesn't appear to specify the DAS's authority after engagement.
The Yaw Damper Authority is only 6 degrees left or right, but I would expect the autopilot to have more than this.
Thanks.
Rgds.
Q.
P.S. Failing that, do you have any values for the 747-400 :-)
Join Date: Oct 2000
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Appears to be a very good question since Iīve now read through the relevant sections of my manuals and canīt find an actual value.. From what I have done in the sim as far as go arounds on one engine from triple-channel appoaches I would assume the autopilot has full authority over the rudder beause of the abrubt yaw when the G/A roll mode is terminated.. It has atleast authority to counter any yaw when full G/A thrust is applied to the "live" engine.. Hope it might have helped.. 
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Taken from engineer training notes:
Autoplilot inputs drive the three directional autopliot servo's that, in turn,drive the aft quadrant assembly.Autopilot inputs are provided for autoland mode only and drives the rudder a maximum of 24.8 degrees. Autopliot inputs backdrive the cable system to provide input to rudder pedal steering.
Autoplilot inputs drive the three directional autopliot servo's that, in turn,drive the aft quadrant assembly.Autopilot inputs are provided for autoland mode only and drives the rudder a maximum of 24.8 degrees. Autopliot inputs backdrive the cable system to provide input to rudder pedal steering.
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"So the autopilot could drive it to 24.8 degrees deflection.. How far could I drive it i.e. what is max deflection??"
The 767 has a limit of about +/-26 degrees at low speed and a limit of +/- 4 degrees at 360 kts due to Rudder Ratio.
Rudder trim is also affected, having a limit of +/-17 degrees at low speed and +/- 2.6 degrees at 360kts.
Regards.
Q.
The 767 has a limit of about +/-26 degrees at low speed and a limit of +/- 4 degrees at 360 kts due to Rudder Ratio.
Rudder trim is also affected, having a limit of +/-17 degrees at low speed and +/- 2.6 degrees at 360kts.
Regards.
Q.
