Hacker News new | ask | show | jobs
by bencoder 1704 days ago
The direction indicator is gyro based rather than magnetic so for most GA it would probably be enough to just learn the offset for the area you are flying and add that when you set/check the DI.

For VFR flying it hardly matters anyway
2 comments
GekkePrutser 1703 days ago
Also, the compass used for calibrating the gyro is pretty small and wobbly. I really doubt you'd be even be able to read that minor difference off it.

Edit: Just read here that in the pacific Northwest of the US there is a 20 degree deviation! I had no idea. Where I flew it was a degree at most.

link
lxgr 1704 days ago
The direction indicator is not a gyrocompass, though – it will eventually drift unless it's periodically adjusted.
link
bencoder 1703 days ago
Sure but in small GA planes you're not likely to be travelling so far that the magnetic declination is significantly different so just keep it in mind each time you reset the DI. Or if you are travelling long distance you could make a note of it along your planned route, or your GPS app could let you know.

My point was that this shouldn't require any instrument upgrades to the GA fleet

link