Interstingly enough, they do seem to work pretty well after a crash. I
investigated a mid-air in 2004 (I'm a Fed, but normally assigned only
to air carrier ops) where one aircraft was cut in half ( a Cessna 210)
and the ELT was in the aft part of the fuselage - pretty well rolled up
in the tin - and the antenna rolled up in another part of the fuselage,
but the coax was still connected. The Thurston County Sherriff's Huey
had no trouble locating the aft fuselage pieces, the ELT was
transmitting clearly. The other Cessna was not so lucky, the antenna
was not connected - because the ELT had been removed. That aircraft
wasn't hard to find - it was in an open field.

All those specific requirements that we have to comply with are
required by the manufacturer to insure that the installation complies
with the TSO. Maybe not real world in the end, but they do seem to
work. From what I've seen and read, most ELT failures are due to dead
batteries or improper installation, or even missing! Note the rule
allows a required ELT to be removed for repair for I think 90 days,
with a log entry, etc.

I made the decision to install an ELT in my glider after reading all
the discussion, seems like a good idea and for $200 what the heck, why
not? This will be harder to do for others because they have to get
somebody to install it and/or sign it off, or they cannot find a good
place to locate one. My glider was easy with a large unused open space
to mount it, many gliders do not have this kind of open real estate
available.

Jim