Originally Posted by Frankster13
I will be needed to calibrate AHRS, Compass and other items on my RV-14A (SF/Bay Area LVK). Does anyone have any tips and trips to make this easier? My plan is to go with the manual steps but wondering if there are any tricks from the RV community for the aircraft side of things.
When you level the plane (to wings level cruise attitude) for the ADAHRS pitch/roll offset calibration, make sure you calibrate the GSU 25 and the G5 together (or one after the other) before moving the plane.
Having a field with a compass rose is great because you don't have to worry about finding a magnetically "clean" location. Be aware that it may be very difficult to find a clean location where your magnetometer calibration will pass. For example, anywhere on the ramp where there is concrete with embedded metal (rebar) will probably fail.
At my local airport I tried all over the taxi-ways and ramp areas before finally finding a spot on the edge of a paved run-up pad at the far end of the field that I can reliably pass the magnetometer calibration (every time).
We agree with Brian that it is ok to perform the initial magnetometer calibration with the engine off if that is easier. If you later have heading problems you can repeat the magnetometer calibration at any time without having to re-calibrate the pitch/roll offsets on the GSU 25 and G5 units.
It is not actually necessary to mark off a compass rose, since all you need is to align the aircraft with magnetic north using a handheld compass to start the process. The GDU will tell you where to pause as you turn right 30 degs at each point in the calibration. You don't need markings on the ground or to use the handheld compass after you get started.
It is also not necessary to lock a brake and spin around in a circle. Just taxi or push the plane around as shown in the manual and stop each time the display tells you to and it will be fine.