Compass for the Northern Hemisphere

[FlyingVizsla]

What is the difference between a compass for the Southern hemisphere and one for the Northern Hemisphere?

 

Looking at the Aircraft Spruce catalogue they are listed separately. If there is a difference then it could be an issue for people importing a/c from the States, or buying from the USA.

 

Sue

 

 

[djpacro]

... and easily fixed - the least of your worries if importing from the northern hemisphere.

 

Although it has caught some people out - the first F/A-18 out of Avalon had them stumped for a while until a "lowly" LAME pointed this out to the "experts".

 

 

[Guest Maj Millard]

There is usually a N or S stamped on the back of the case. If you try and 'swing' a North biased compass here, you'll be lucky if you get it within 10 deg of correct. Some you won't get within 20 deg no matter how hard you try.

 

The correct error by the way is not more than 1-2 deg at best.

 

many of the Euro imported aircraft will come equipped with N biased compasses.............................................................Maj...

 

 

[Old Koreelah]

Wow, thanks, Ignition! Perhaps that explains why I've had so much trouble with my damned compass! Even after I spent lots on a rebuild, it's still inaccurate. I'll have to check which hemisphere it was meant for. There are so many factors affecting a magnetic compass: local deviation, migrations of the magnetic poles and metal in the a/c, etc. that I rarely rely on it. To make matters worse, the earth's magnetic field is probably well overdue for a reversal. Any century now it's likely to flip, so I'm using my iPhone instead!

 

 

[fly_tornado]

I noticed when I was going over my tornados both the magnetic compasses where inaccurate, e-w wasn't too bad but n-s was all over the place but if I rotated the compass down toward the north it's less so.

 

 

[Guest Crezzi]

I did a fair bit of flying in S hemisphere in a trike from N hemisphere - even in straight flight at constant speed the compass dip is quite noticeable. Attached photo from near southern tip of Africa

 

[ATTACH]12838.vB[/ATTACH]

 

 

 

[eightyknots]

There are so many factors affecting a magnetic compass: local deviation, migrations of the magnetic poles and metal in the a/c, etc. that I rarely rely on it. To make matters worse, the earth's magnetic field is probably well overdue for a reversal. Any century now it's likely to flip, so I'm using my iPhone instead!

It's more likely that your iPhone goes out of date (due to the new G6 network, etc) well before next century's magnetic reversal.

 

 

[Old Koreelah]

You're right, eightyknots, I was speaking in jest. Even the might Apple is only a fleeting thing in human history, let alone geological time.

 

 

[Guest Andys@coffs]

Less of an issue now with LCD and Plasma displays, but CRT tubes were also made for N or S hemispheres. Like DJPACRO said on the F18's I saw military displays that came out of the Northern hemisphere appear to be out of adjustment here when first powered on....

 

Andy