[WWI] Roland D.VI wing mounted compass

ernest thomas reason108 at hotmail.com
Mon Jan 10 17:57:38 EST 2005

>From: Steve Cox

>And where exactly in an aircraft is level for more than a few seconds at a

The floating needle/ball/wheel/whatever of a compass will be level, for the 
most part, when an aircraft is in a state of sustained straight and level 
Magnetic compasses are subject to variation and deviation errors. Variation 
is the angle between true north and magnetic north and varies with the 
compass' position on the earth.
Deviation is caused by magnetic fields in the vicinity of the 
compass,(electromagnetic fields generated by running engines, radios, etc.)
Magnetic compasses in aircraft are also subject turn and bank errors, and 
iirc, acceleration/deceleration errors.
True, a fighter plane in a skirmish is rarely in a state of sustained 
stright and level flight. BUt in a skirmish, a pilot isn't too concerned 
about compass headings anyway. At least I wouldn't think he his. Never 
having been there myself, I'm only guessing at that.
My point is this: a compass with it's axis aligned parallel to the horizon 
won't work properly.

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