airman13, how are you going to make your mayday call on 406MHz?
Be careful of generalisations. I think you'll find that Emergency Locator Transmitters will have to operate on 406MHz from Feb 2009. The change is being made, in part at least, so that 121.5MHz remains clear for voice transmissions rather than suffering interference from ELT broadcasts, many of which (the vast majority, I believe) are 'set off' inadvertantly or in error.