Results 1 to 2 of 2

Thread: Heading hunt

  1. #1

    Heading hunt

    In the efis mode, lat heading, the heading continually hunts back and forth 5 degrees. In lat arm mode it's as steady as a rock. Any suggestions?

  2. #2
    Step 2a Adjusting Autopilot Lateral Gain Settings

    Whenyou adjust the heading bug to a new heading over 90 degrees away the planeshould capture the new heading with minimal overshoot.

    Thereare two Gain settings that control how the airplane responds in Lateralcontrol.

    EFISROLLGAIN ; This is set in the EFIS AP/FD -> SETTINGS -> LATERAL -> ROLLGAIN
    APLateral Activity ; This is set in theAutopilot

    TheEFIS ROLLGAIN controls how far the airplane should bank for a new heading. TheAP Lateral Activity controls how fast the autopilot roll servo responds to rollcommands.

    STEP1 ADJUSTING THE AP SETTINGS

    1. Verify that the AP LAT Torque is set to 12
    2. Engage the Autopilot using the AP button so that the aircraft is following the heading knob on the Autopilot.
    3. Adjust the LAT ACT on the autopilot so that the aircraft performs well when you turn to a new heading using the AP knob. You should make turns of over 90 degrees and continue to adjust until you are satisfied with the results.

    STEP2 ADJUSTING THE EFIS SETTINGS

    Youcan check the current commanded bank angle being sent from the EFIS to the AP fromthe check list page, it is displayed asAP ROLL. The EFIS uses the followingcalculation for AP Roll angle.

    APROLL = (Heading Bug – Magnetic Heading) * EFIS ROLLGAIN

    HeadingBug 090
    MagneticHeading 360
    EFISROLLGAIN .05

    APROLL = (90 – 360) x .05
    = -13.5 degrees of bank angle

    TheEFIS limits the maximum bank angle to what is required for a standard rateturn.


    1. Engage the Autopilot using the EFIS button so that the aircraft is following the heading bug on the EFIS.
    2. Adjust the ROLLGAIN on the EFIS so that the aircraft performs well when you turn to a new heading. You should make turns of over 90 degrees and continue to adjust until you are satisfied with the results.

    Ifthe EFIS ROLLGAIN is set too low the airplane will tend to be sluggish and slowto respond to new headings. If the EFISROLLGAIN is set too high the airplane will tend to overshoot the heading bugand be jittery.
    Rob Hickman
    Advanced Flight Systems Inc.

Similar Threads

  1. No heading bug 5800T
    By Acrophil in forum AF-5600 & AF-5500 General Discussion
    Replies: 2
    Last Post: 11-13-2015, 01:21 PM
  2. Two 5000 don't match heading
    By BSteeves in forum AF-5600 & AF-5500 General Discussion
    Replies: 1
    Last Post: 07-13-2015, 04:55 PM
  3. My Magnetic Heading is out by about 12 degrees
    By Surfboy in forum AF-3400s, AF-3500s, AF-4500s ... General Discussion
    Replies: 3
    Last Post: 02-21-2014, 02:32 AM
  4. Autopilot will not follow heading bug
    By TrueAirSpeed in forum AF-3400s, AF-3500s, AF-4500s ... General Discussion
    Replies: 3
    Last Post: 04-03-2012, 04:55 PM
  5. Magnetic Heading Errors
    By Rob Hickman in forum Technical Support Documents
    Replies: 2
    Last Post: 01-08-2012, 12:27 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •