On Wednesday, December 5, 2012 4:19:23 PM UTC+1, son_of_flubber wrote:
1.Why do many gliders have two variometers?
2.Assuming for a moment that you are not flying in the flatlands, how often and under what scenarios do you use your compass? What are some good exercises for developing airborne compass skills?
3.If you needed panel space for a PowerFlarm display, which existing instrument would you delete (if any)? (Assume a PDA is present.)

1. Backup "get home" vario. Unlike the other posters so far, I don't bother with a mechanical, instead have two electrics with audio, with two completely independent battery systems. Has worked as designed so far for the past 12 years. Oddly, it was the pitot static system that killed my main vario once, when a bug clogged the pitot tube and resulted in incorrect readings of the primary flight computer/vario. Backup worked fine - and I really like having two varios to crosscheck and strongly dislike not having audio.

2. I have never used my compass in anger, either in the mountains or flatlands. It's only in the panel because it's required. Note that I'm a retired AF navigator, so know a little about compasses and navigation. I think a whiskey compass in a glider is basically useless unless you do the preflight planning to use compass headings and a marked up chart. Yeah right...get a backup GPS if you don't have a redundant system.

3. I would pitch the compass without hesitation. As it is, my Flarm display is going to hide my backup vario, and my Oudie will hide my compass, but both are on RAM mounts and can be moved if needed (but with audio, I don't really need to see my backup vario).

Kirk
66