5Z wrote:

Except for a few bits in the message itself, there is no difference
between 911, HELP, or OK. You can test it to your heart's content by
sending either of the latter messages to yourself or friends.

I don't know about the UK, but in the US, dialing 911 from my house
just to see if it works is not permitted. So I have to trust that if
I get a dial tone, I'll be able to reach 911.

Nor do you turn on your ELT and wait for search and rescue to show up,
to see if it "works".

It's possible that the connection between the SPOT message handling
center and their 911 center is down, but I assume the message handling
system will keep trying until a human acknowledges the request. It's
also possible the 911 button on your unit is broken, but then the LED
won't flash, and you'll know it. If the LED flashes, and if a recent
OK message went out, you can be fairly confident that the 911 will go
out as well.

If you don't trust their 911 service, make the "send help" button your
personal 911, with a friend/wife/employee with email or a cell phone
ready to call search and rescue. Not as elegant, but you can "test" it.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org