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 :-) |
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.. :(
|
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. |
Thank you gentlemen. Couldn't have asked for (and got) more :-)
No doubt, PPRuNers are the greatest! Cheers. Q. |
So the autopilot could drive it to 24.8 degrees deflection.. How far could I drive it i.e. what is max deflection??
|
"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. |
Thanks.. You never know when that piece of information might prove useful.. :)
|
All times are GMT. The time now is 05:13. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.