GRT Avionics, Inc.
May 2019
Sport SX Install. Manual
27
Rev. A
determine your ground track. The GPS cannot determine your track unless you
are moving.
2. After the aircraft is positioned correctly, turn ON the GRT Sport. (If it was already
on, then turn it OFF, and then back ON again.)
3. Allow at least 1 minute for the AHRS to fully stabilize.
4. Press any button on the EFIS display to bring up the soft key labels. Press the SET
MENU soft key, and then scroll to and select AHRS Maintenance. Scroll to and
select the Magnetometer Calibration field on this screen.
5. Press Start soft key.
6.
The first question is “Are you sure?” Press YES if you are sure.
7. Verify that
the airplane is still pointed to magnetic north. Answer the question “Are
the aircraft, AHRS, and magnetometer pointing to magnetic nor
th?” with YES. A
message will appear at the bottom of the screen indicating that the system is
waiting for the gyros to stabilize.
8.
As soon as the message “Calibration in Progress” is displayed (within 15 seconds),
rotate the aircraft 360°, plus an additional 20°, in a counter-clockwise manner
(initially towards west). The airplane does not need to be rotated in place, but
simply pulled or taxied in a circle. The airplane must be rotated completely through
the 380° past magnetic north within 3 minutes of initiating the calibration. The
airplane should be rotated slowly, such that it takes approximately 60 seconds for
the complete rotation.
9. If calibration is successful, the AHRS will re-start itself automatically and begin
using the corrections. While re-starting, the AHRS will not provide any data. This
will result in the AHRS data disappearing from the display unit for about 10
seconds.
10. If calibration is unsuccessful, one of two things will happen. In either case, the
calibration procedure must be repeated.
a. If the airplane is rotated too rapidly, the calibration will not end after the airplane
has been rotated through the 380°.
b.
It will exit calibration mode and will show “Calibration INVALID - Maximum
correction exceeded” if a correction of greater than 127° is required (Invalid -
OVERLIMIT will be displayed on the AHRS maintenance page next to the
Magnetometer Calibration field). A correction of greater than 127° can be
caused by incorrect mounting of the magnetometer, the presence of ferrous
