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Old June 22nd 10, 04:43 PM posted to rec.aviation.soaring
Darryl Ramm
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Posts: 2,403
Default 121.5 ELTs banned

On Jun 22, 7:32*am, jb92563 wrote:
On Jun 21, 4:01*pm, brian whatcott wrote:

Since satellite cover has been withdrawn for 121.5
(High false alert rate, poor localization)
406.0 and 406.1 ELTs will be needed, following a recent FCC determination.


Brian W


Since the bereaucrats love so many rules, why not make another and let
Gliders and ballons use PLB's like SPOT since in our sport we often
have support crews that will monitor our progress in any case, making
SPOT a very convenient tool for us and our crews.

Ray.


First a SPOT is *not* a PLB. A PLB is a specific device regulated by
the FCC that transmits on 406 MHz to COAPAS-SARSAT (and also a 121.5
homing becon). It is essentially a lower power, smaller, manually
activated 406 MHz ELT.

SPOT is a private service run by Globalstar. The (multi-)government
service is COSPAS-SARSAT and that provides pretty impressive emergency
notification service for marine (EPIRB), Aviation (ELT) and private
(PLB) use. It makes no sense for he government to promote SPOT over
SARSAT-COSPAS.

There is no federal requirement for a glider to carry an ELT. There is
an apparently well intended but badly outdated SSA contest rule that
allows a CD to require gliders to carry an ELT. The issue I have with
that is a 406 MHz PLB is likely a much better SAR alerting device than
an old 121.5 MHz ELT even if you could properly mount one in the
glider. ELTs in light aircraft have an abysmal activation failure
record, and I suspect that will be much worse in gliders with many of
them improperly mounted and the lower impact energy of many glider
crashes. SPOT tracking is great, a 10 minute position report gives you
a simple area of uncertainty roughly about the same as an old SARSAT
121.5 MHz Doppler fix, but because you can usually use the glider path
to predict the flight direction it's actually better than that. At
least it's a good start for a search operation. If the pilot can
activate "911" on their SPOT and it gets a view of the Globalstar
satellites and a GPS fix then their final position is know as well. I
prefer the redundancy of havign both SPOT and a PLB and the technical
advantages of a PLB for that ultimate distress situation, but if I am
in distress can I'll be activating 911 on my SPOT and activating my
PLB. At a minimum the old SSA contest rule for ELTs could be modified
to allow a CD if they choose to require SPOT and/or "406 MHZ PLB or
ELT carriage".

Darryl