When I've looked at other pilot's Spot tracking output, the majority are quite unreliable in the sense that a significant portion of the transmitted track points are not being received by the Globalstar satellite network. I think this largely stems from a failure to appreciate what a 'clear view of the sky' really means. It is not the overhead sky that matters. IT IS THE 360 DEGREE VIEW OF THE HORIZON THAT IS IMPORTANT.

Catching a Globalstar satellite is a statistical matter. There are only so many satellites whizzing around in low earth orbit. The satellite that you need at any given time will almost always be very near to the horizon; having a satellite anywheres near overhead is a very rare occurrence. The significant consideration is that a mounting strategy that gives only a partial view of the horizon, will result in a statistically similar proportion of tracking messages that don't get out. To have a view of the 360 degree horizon, the unit needs to be mounted flat and high.

Common practice these days is to mount Spot on ones parachute. There is a certain logic to doing that. But there is also a serious flaw in that parachute mounting is frequently not giving reliable tracking mode performance. The problem relates to signal lose through the human body and surrounding airplane parts and the difficulty in keeping the unit flat to the horizon.

Consider the searcher's paradox when a downed pilot uses a Spot which is not transmitting reliably. Searchers will sensibly examine ones past Spot unit performance. If they see that it is not uncommon that your Spot unit misses two or more 5 minute transmits in a row, then the search area becomes something like a 15 minute assumption; that would be like a 25 mile search radius which equals 1900 sq miles. You may never be found. Spot owners should consider this trade-off carefully. My own opinion is that it is much better to have reliable tracking operation than it is to have the unit attached to my parachute.

The other significant point to be made is that Spot is obsolete technology now. InReach is much superior. Tracking interval can be easily set down to whatever you'd like (and willing to pay for); available settings include 5 minute, 2 minute, 1 minute and 30 seconds. InReach communication is fundamentally more reliable because it is a two-way protocol. InReach reports altitude with GPS position which in a search situation is likely to be invaluable. InReach provides two-way text messaging so you can (hopefully) communicate with potential rescuers regarding your situation.

Of note is the fact that Globalstar has said that they will offer a two-way Spot unit pretty soon too. Hopefully that will result in pricing competition with DeLorme.

My condolences to Joe's friends and family. All of us feel great pain when a pilot is lost. It's a bit incongruous to discuss finer points of technology in the face of such a lose. Yet we do need to sort out the problems when we loose one of our own.