But that assumes the beacon isn't lost, and that it works at all. Since the beacons aren't ever tested ever leaving the factory - at least my ResQFix isn't testable without needing factory service afterwards to replace the batteries - I'm not sure it's reasonable to assume the beacon works.

(I vaguely seem to recall that there was one set of tests run on small planes - by the FAA? SARSAT? - in Alaska? - where many beacons - 30%-50% - actually didn't work when tested. This is hazy memory but it did leave an impression not to assume too much of equipment that is never tested)


The SARSAT protocol that the beacons use to broadcast to the satellites has seven spare bits if I recall correctly. It would be possible to add encodings for activation reason - "OK", "test", "need rescue, not time critical", etc.

The main problem is that you don't know how long the beacon must be left active before the satellite pass and you hate to consume a non-replaceable battery on an OK in case an actual emergency arises later.

The other problem is that satellite resources aren't unlimited. From the documents I've read discussing doppler shift measurement in the satellites there is going to be a definite limit to the number of active beacons the system casn handle at any one time. And since this is an international system piggybacking on other people's satellites increasing capacity might not be easy, and definitely won't be cheap.