ELT antenna in composite planes.

Dave,

It was about a couple thousand feet above ground - about what I
locally fly. And it was probably more than 60 miles range. Up at 12K
msl above Washington state mountains had one digi got me about 100
miles. My rough comparison is with normal radio aircraft reception at
say 8000 msl - aircraft to aircraft communication fizzles out about
60? miles. So the ducky isn't bad "transmission" range in direct line
of sight situations. But it seems bad in reception.

Yeah the current APRS catch is the HAM license. Wish somehow it was
easier to get a tracker for GA use. APRS tracking can be a great
safety factor.

On Oct 31, 10:32 pm, Dave S wrote:
wrote:


60 miles coverage on the ground? to what elevation of a receiving
antenna? Details.. details..

As for APRS.. while I applaud it, the "catch" is that you have to have a
HAM radio licence and ham radio equipment to utilize the existing VHF
packet network.

Dave

Yeah the current APRS catch is the HAM license. Wish somehow it was
easier to get a tracker for GA use. APRS tracking can be a great
safety factor.


Its not really that difficult, conceptually. Especially when they revise
the bandplan to the next narrowing of the bandwidth. Dedicate an
aviation channel or two nationwide (I'm sure the band planners can spare
ONE or TWO when the next doubling of available frequencies occurs)
packet reception. Digipeaters wouldn't really be needed, provided enough
igates exist on enough tall towers.

If enough aircraft in an area had this, it would also allow tracker
equipped aircraft to see OTHER tracker equipped aircraft as a sort of
poor man's TIS/TCAS, but the beaconing rate would need to be much faster
to support that in real time.

There is no monopoly on using APRS on HAM only, and you can put a TNC on
theoretically any radio, only infrastructure concerns.

Use smart beaconing, so that when traveling straight line, beaconing is
minimized, and use corner-pegging logic so that a beaconed datapoint
defines when a course change occurs. By setting up a system with smart
beaconing you could handle hundreds of beaconing aircraft in an area,
with minimal collisions.

One doesn't crash 1000 feet in the air and line of sight is what really
works. That's why they use a satellite which helps immensely when down in
the trees and valleys


--
Cy Galley
EAA Safety Programs Editor
Always looking for ideas and articles for EAA Sport Pilot
New address -

wrote in message
ups.com...
Dave,

It was about a couple thousand feet above ground - about what I
locally fly. And it was probably more than 60 miles range. Up at 12K
msl above Washington state mountains had one digi got me about 100
miles. My rough comparison is with normal radio aircraft reception at
say 8000 msl - aircraft to aircraft communication fizzles out about
60? miles. So the ducky isn't bad "transmission" range in direct line
of sight situations. But it seems bad in reception.

Yeah the current APRS catch is the HAM license. Wish somehow it was
easier to get a tracker for GA use. APRS tracking can be a great
safety factor.

On Oct 31, 10:32 pm, Dave S wrote:
wrote:


60 miles coverage on the ground? to what elevation of a receiving
antenna? Details.. details..

As for APRS.. while I applaud it, the "catch" is that you have to have a
HAM radio licence and ham radio equipment to utilize the existing VHF
packet network.

Dave

Cy,

That is assuming the ELT will always work. During a crash the ELT may
be destroyed and/or your personal satellite PLB may not go off if you
are injured. According to APOA, ELT failure rate is about 27% - not
too good, not good for Foster, the man with the satellite signal
watch. The 406's failure rate is about 19% - still not too good ( see
http://www.montanapilots.org/ ). At 1000 AGL with a 12/1 glide ratio
the plane is no more than about two miles from the last point - and
you roughly know the direction. But seldom APRS will not get detected
at 500 AGL. The standard ($1000+) 406 ELT accuracy is about two
miles. A $3000+ 406 will transmit your position to the satellite from
your aircraft gps navigation - assuming that your avionics will work
after the crash. Hmmm... $1000, $3000??? An APRS tracker is only
couple hundred bucks - NO subscription fees.

On Nov 5, 9:59 pm, "Cy Galley" wrote:
One doesn't crash 1000 feet in the air and line of sight is what really
works. That's why they use a satellite which helps immensely when down in
the trees and valleys

--
Cy Galley
EAA Safety Programs Editor
Always looking for ideas and articles for EAA Sport Pilot
New address -