On 6/22/04 9:58 AM, in article ,
"Todd Pattist" wrote:

"Ed Byars" wrote:

Specifically, I have for several years, used the $185 Ameri-King ELT
available at any glider or aircraft supply house. I like it because it is
compact, easy to mount, and uses only 6 of the inexpensive D cell flashlight
batteries available at Walmart or any hardware store. You can take the unit
out, plug in the furnished portable antenna and a microphone and transmit
while you are awaiting rescue or walking back to civilization.
This unit was in use for my two successful activations.
Ed Byars

I'm glad to hear the Ameri-King worked, as that's what I'm
using now in my glider. OTOH, the article cited by Chris
says 121.5 ELT's can only be located within 12 nm radius or
450 square nautical miles. The 406 units allegedly get
within 2 nm, and it takes a 406 plus GPS to get right to
you. Given those numbers, I'd really like to confirm what
Peter Masak was using before I make a decision on what to
buy for my airplane (and possibly swap into the glider). If
anyone reads this, knows what he had installed, and does
not want to post here, I'd greatly appreciate an email at:



Thanks.
Todd Pattist - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)
The 121.5 ELT signal is "heard" by satellites passing overhead. They record
both the Doppler shift and relative signal strength. After several passes by
one (or more) the search area is localized to the approximate area that
Chris mentioned. As soon as the search is dispatched, they use direction
finding equipment to rapidly narrow the search and home in on the target.

The big difference between 121.5 and 406 ELTs is (not counting the 2009
issue) is the time it takes to get the search established. For 121.5, it
takes several satellite passes (at about 90 minutes each) to raise a
warning. With the 406, it's almost instantaneous, and the dispatch center
can call to verify that a search is needed and dispatch it right away.

I do not know what ELT peter was using. But, remember that the 406 ELT also
transmits a homing signal on both 121.5 and 243 MHz. If I remember
correctly, a tow plane was sent looking for Peter (and a 121.5 signal) at
the end of the day. The local search began as soon as possible using the
121.5 signal.

However, on the 2 occasions where I had inadvertently put my glider in the
trailer with the ELT (121.5) transmitting, the search party was at my
doorstep (the glider trailer was in the driveway) within 8 hours.

I have had an ELT in my glider since 1988 when I started flying Cross
country seriously.

--
Bob
bobgreenblattATmsnDOTcom --fix this before responding