On Jun 22, 3:51*am, Scott wrote:
Darryl Ramm wrote:
I'd much rather have a manually activated PLB instead of an ELT -- and
personally I use a SPOT tacker in tracking mode to provide a rough
last-known position that does not rely in impact activation or being
physically able to active a PLB.

Darryl

Are these 406 units ONLY activated manually? *If so, what if a guy is
too busy flying the plane and forgets to activate the 406 unit? *If
that's the only way to set one off, the rescue rate may be less than the
121.5 units...

A 406 MHz ELT is impact activated. This requires the unit to be
properly mounted, the crash to have sufficient energy to trigger the
ELT and you also need apparently a lot of luck since correct
activation rates are pretty low (~20%?) in GA aircraft. And false
alarms (especially on older 121.5 Mhz ELTs) are high. But stats are
hard to get, and we need to be careful about comparing different
generation ELTs. I expect worse in many glider installs.

With a PLB post crash and/or landing you need to manually activate a
PLB. Trying to activate on in the air with their fold out antennas is
going to be difficult. If you can move then putting the unit flat on
the ground away form obstructions will likely produce a better signal
than many of the very bad ELT antenna installs I've seen in gliders.
Modern 406 MHz ELTs are required to be activated from a panel switch.
Older ELTs (without that switch) if they did not automatically
activate on impact may require more effort to get to and activate than
manually activating a PLB. If you cannot manually activate the PLB you
may be dead. While finding a fatal crash victim, especially with least
danger exposure to SAR personal, is important. A SPOT messenger with
tracking is a great start for that case.

There are SAR experts like Doug Ritter who keep trying to emphasize
that since ELT activation is so unreliable that a PLB is actually
better than an ELT. Carry a PLB first and maybe have an ELT as backup
for that, not the other way around.

Darryl