Reply to post: Which way?

Which way?

I did work on the autopilot software for a British fighter jet once.

One of the stories we heard was on one of the early versions of the software the 2 digital compass reading were averaged to produce a more accurate heading, unless one was obviously wrong in which case it was dropped.

But the variable held the data as -1 for magnetic south (180 deg), 0 for magnetic north, and 1 bit less that +1 for 179.999 deg.

So if one compass was reading 180 deg, and the other 179.999 deg instead of averaging almost 180 deg it computed a 0.

Good job that one was spotted before the aircraft got airborne.