JJB*
Captain
Flight distance : 12165479 ft
Netherlands
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Geebax Posted at 11-23 17:17
Thank you. Where I live in Australia there used to be a Royal Australian Air Force base, and on that base there was a concrete pad at the side of a taxiway. The pad was circular and had a marker showing magnetic north and true north. The idea was to line up the nose of the aircraft so it was pointing to magnetic north, then check if the aircraft's compass agreed with that alignment. If not, the compass could be unlocked and rotated in its gimbal to line up with the marker. This was called 'swinging the compass', and the purpose was to correct for any magnetic influence contained in the aircraft to 'calibrate' the compass.
This wa the only time I have every heard of the compass being actually adjusted this way. But note that it differs from the DJI approach in one important factor, the DJI approach does not require you to point the aircraft towards a 'marker' of any sort. Hence the reason I refuse to describe the DJI process as 'calibrating' the compass, unlike the procedure used by the RAAF to calibrate their compasses.
Great story!
Not only was the aicraft nose pointed to the N marking, but nose moved in sequence every 30 degrees.
On each point readouts on the aircraft magnetic compass system and of the "handheld" calibrated compass in front of the nose. After this 360 swing some calculations were made and the average off-set adjusted on the aicraft compass. Flying longer distances aircrew had to adjust manually a variation correction to the compass.
On post processing of the compass swing a 360 correction card was made and sticked next to a standby (mandatory) small magn compass in the craft.
Happily DJI uses a simple magnetometer as a compass, no need and impossible to do a compass swing like above, no one has a checked on true N compass swing spot in their garden
BTW My MA2 came out of the box, did many many flights without compass calibration. (and china is not next to my country)
I only had to do a compass cal bc the app told me so.
My MM1 needs every 31 days of after traveling some distance a compass calibration, days and last position of cal are saved somewhere, data shows up in the DAT file.
cheers
JJB
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