This is an old thread but I don't think it'll hurt to leave my comments.
I'm an old pilot and I have some thoughts on civilians transmitting on aviation frequencies. I'm getting back into the airline business after a decade away, and a new phenomenon I've noted is people on the ground transmitting things that make them laugh (burps, animal sounds, music) on the aviation emergency frequency (in my experience this occurs almost exclusively in the southern US - draw your own conclusions).
I initially wondered how civilians got hold of radios that transmit on the AM air band but I think I figured it out. Anyone can buy a Yaesu VX-7 and, following instructions on YouTube, in less than five minutes modify it to transmit on the air band. I assume some other HTs can be just as easily reconfigured.
I could write pages about why it's stupid to distract pilots maneuvering aircraft in crowded airspace at 80% of the speed of sound, but that can wait for another day.
What interests me more, at the moment, is the idea that having the ability to transmit on aircraft freqs adds a reasonable margin of safety in the wilderness. It really does not.
There are simply too many variables that must cut in your favor to initiate a rescue response by contacting an aircraft a minimum of 6 miles away (if it flies directly over head) moving at 8 miles per minute and flown by two very busy pilots with their attention focused on the air traffic control frequency rather than the emergency frequency.
I've been flying for 25 years and I have a good idea of what goes on in most cockpits. Don't bet your life on a passing aircraft. Take a satellite phone or an EPIRB with you into the wilderness. Sure, it'll be more expensive than unsoldering a couple of jumpers in your HT. But, what's your life worth? How much would your kids say your life is worth?