fans90d4f438
lvl.3
Flight distance : 451335 ft
United States
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Griffith Posted at 2017-1-23 06:43
Regardless of what any manuals say or don't say, I always re-calibrate the compass when traveling more than 100-200 miles from my last flying location. Near my home, the magnetic deviation is about 1 degree per 60 miles. It gets greater at latitudes closer to the poles. Always re-calibrate a fair distance away from metal structures and you won't experience any problems.
except excess calibration probably is doing more harm..than good.
From another forum..
"There are typically only two reasons why a compass would need calibration: Magnetic deviation and changes in magnetic declination.
Magnetic deviation is compass error caused by magnetic fields which can be hardware related (near-field), caused by large metal structures or sources of strong magnetic interference like power lines, etc. (local), or by geological influences like iron deposits in the earth (regional).
Near-field magnetic deviation is usually the result of changes in the device's hardware like adding or moving a battery pack, camera, etc or replacing motors with ones with different magnetic characteristics. If you haven't done anything like that then it shouldn't be necessary to re-calibrate your compass.
It's also not wise to re-calibrate your compass to correct for local magnetic influence like large buildings and power lines because what you'll actually be doing is introducing error once you fly away from those things.
It may be necessary to re-calibrate the compass to correct for regional compass error, but that will depend on how widespread the magnetic influence is throughout the area you will be flying in. Local pilots and/or the local airport will know whether there is regional magnetic deviation in the area.
The other reason it might be necessary to re-calibrate a compass is to correct for changes in the magnetic declination between true north and magnetic north as you change locations. But devices which are GPS enabled know where they are and all but the most rudimentary systems will automatically correct the magnetic declination values for changes in location. Consequently, it's not necessary to re-calibrate the compass on most GPS enabled devices for differences in location.
The bottom line is those of you who insist on re-calibrating your compass frequently are most likely being counterproductive. If the compass is calibrated correctly to begin with and you haven't made any changes to the hardware (which, BTW, includes any abrupt changes in velocity [crashes]), then there's probably no valid reason to perform a compass re-calibration)."
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