On Thursday, April 5, 2018 at 2:12:57 PM UTC-4, Tango Eight wrote:
On Thursday, April 5, 2018 at 1:33:35 PM UTC-4, wrote:
On Thursday, April 5, 2018 at 1:10:39 PM UTC-4, Tango Eight wrote:
At 7pm (or any other time), you'll see one of three things from a cell phone track, a) a track still being laid down, b) a track that stopped for some reason at near ground level, c) a track that stopped for some reason at some much higher altitude. There is useful information here in all three cases.


-Evan / T8

Case "C" ("a track that stopped for some reason at some much higher altitude") may mean: glider entered an area with no cellphone coverage even at higher altitudes. Or, maybe the glider descended too low for cellphone coverage in that area, and is currently on the ground - or working on a low save. Or, it may mean that the battery in the cellphone died. Or the app crashed (not the glider). Or the cellphone slipped under the pilot and lost GPS signal. In short, not a lot more info than having no tracking at all.

True. So what? Case C turns out to be rare in practice. But the additional point is that case C clearly indicates a system failure, not cause for immediate concern. That's preferable to the Spot failure I had over the boonies at the Canadian border.

Not all the possible meanings of "case C" are a system failure.

Also, Case A ("a track still being laid down") doesn't tell you whether the pilot WILL land out later - which may or may not be reported later as a "Case B" - or a phone call. And Case B ("a track that stopped for some reason at near ground level") doesn't tell you whether the pilot is safe, and where exactly he is, and how to get there. Lacking post-landing communications you're always left in the semi-dark as to the real situation. I agree that in the bad case of an unsafe landing a "case B" truncated track might help search and rescue to some extent.