A working GPS receiver with a view of the sky to acquire GPS data must be connected
to the SkyView system in order to perform a compass calibration. SkyView uses GPS-
derived position information to calculate magnetic intensity, declination, and
variation.
During the on-ground compass calibration it is important to perform the compass
calibration in an area that has been verified to be magnetically neutral. The presence
of steel reinforcement (rebar), electrical power lines under the tarmac, or other
natural deposits of ferrous metals can result in an inaccurate compass calibration.
Airport compass roses are usually verified to be magnetically neutral and thus are
often a good location for performing a compass calibration.
For more information on this issue see FAA Notice Number: NOTC4031:
https://www.faasafety.gov/files/notices/2012/Aug/CAUTION_TLP_031612_Rev10.pdf
On-ground Compass Calibration Procedure:
1. Turn on the SkyView system and allow it to warm up for a minimum of 5 minutes.
2. Move the aircraft into position so that it is convenient to orient it in the four cardinal
directions.
3. Enter the Setup Menu on the SkyView display and go to the Compass Calibration Wizard
(SETUP MENU > HARDWARE CALIBRATION > ADAHRS CALIBRATION > COMPASS
CALIBRATION). Note - GPS data on the Compass Calibration Page must be green. If it is
red, GPS data is not valid.
4. Orient the aircraft to North, South, East, or West.
5. When the aircraft is stable at the chosen orientation, push the button indicating the
direction the aircraft is oriented in. Example – when the aircraft is pointed North, push
the NORTH button.
6. Wait for data collection to reach 100%.
7. Rotate to the next cardinal direction and repeat steps 4, 5, and 6 for any remaining
headings.
8. If there is a SV-ADAHRS-200 and SV-ADAHRS-201 installed, the Compass Calibration is
performed simultaneously. If the Compass Calibration fails on only one of the units, a
message will appear:
CALIBRATION FAILED – S/N xxxx
9. CALIBRATION COMPLETE appears when calibration is complete. Press FINISH to return
to menu navigation mode.