On Thursday, October 29, 2015 at 5:32:57 PM UTC-7, wrote:
When you guys get finished counting up your electronics with triple redundant power supplies, keep in mind that you still have a single point of failu the GPS satellite system. I realize I'm ignoring phones that use the cell towers to triangulate your position but none of the whizzy soaring-specific gadgets have that capability, to my knowledge.

I've used a magnetic compass a LOT in nearly 3,000 hours of glider flying.. Before GPS it was indispensable. I still refer to it occasionally for quick reciprocals (it's a vertical card). And it's nice to know that with it and my paper chart (yeah, how quaint), I could still get home. Of course, forget getting credit for the flight since the logger is worthless if the GPS system is taken down. Oh, well. It sits way forward on the glare shield and doesn't get in the way so that's where it will stay.

Chip Bearden
ASW 24 "JB"
U.S.A.

A compass might be useful for navigation in the trackless flatlands, but out west the 12 - 13K mountains actually make better reference points even if you can't see the sun. And are pretty immune from GPS interference. Now if the Big Earthquake comes, sinking the mountains into the sea, on a cloudy day, during a GPS jamming session, maybe I'll be looking at the compass. But even then it'll be the electronic one. If the poles happen to pick that day to reverse, then we'll all be in trouble.