If an aircraft crashed in a deep ravine with steep walls would the signal emitted by the emergency beacon reach a satellite?If the signal usually can reach several satellites but can't reach any of them from the ravine could we deduce anything about the nature of the ravine or the position of the aircraft in terms of latitude and longitude,from the paths the satellites take in the sky? Can emergency beacons be rendered useless by an airplane on fire or by a strong impact? How low do the batteries need to be to cause the beacons to fail to work properly? Can the atmosphere - particularly the charged ionosphere - stop beacon signals (120 -450 Mhz) under certain circumstances? Would an emergency beacon in an airplane covered by sand or snow be incapable of signaling to a satellite? And what about a beacon that gets wrapped in metal from a crash?