"Only a beacon will get help reliably overhead. We've spent days searching for aircraft that were seen to disappear in the circuit."
About a year back the Police turned up to the Flying Club asking if a beacon may have been set off here. We all said no and he said it seems to be from this area but the GPS point was 20+ miles away out in the water in a bay.
I suggested to go to work and put the base station radio on 121.5 (he said it was 406 but that is another story most us know). Anyway they agreed and nothing was picked up, I said I know that on the ground this due to aerial has a x range in these directions.
Basically we only knew all information they had and they showed me 406 map location, was not where the registered owner was (a WA politician in a hire car on holiday).
Forget reliable and no never did find the location of the device.