
If you happen to be considering upgrading to a new 406 ELT, then take a close look at the benefits as compared to the old 121.5 ELT. The 121.5 ELTs are no longer monitored by satellites, the primary means of detection. The new 406 MHz emergency locator transmitters are digital and very accurate. If combined with GPS, they can provide essentially pinpoint accuracy. Even without GPS, the satellites that detect them can get a very localized position and use 121.5 (built into most new 406 ELTs) to home in on the location once rescue crew arrive.
There benefits of the new 406 ELT are really too numerous to list. The accuracy, dependability of activation in event of a crash, high transmit power, and registration to each specific user, make the units essential in any airplane.