Like all pilots, I don't have a crash landing scheduled for the foreseeable future. But should the unexpected happen, here's what I would have to look forward to with both types of ELTs. First, the 406 has 50 times the transmitting power compared with my old 121.5 unit. According to Collins' article, 121.5 MHz ELTs only logged one save per 1,000 alerts -- that's a lot of false alarms. Even if it works as advertised, my old ELT would require search parties to scour 483 square miles, compared with 30 square miles for a 406 MHz unit. Add a GPS receiver and that area is reduced to .012 square miles. I'm lousy at geometry, but it sounds like they could find me in my back yard.