On Fri, 10 Jul 2009 09:40:06 -0400, Mike Ash wrote:

In article ,
Gezellig wrote:

On Fri, 10 Jul 2009 09:01:43 -0400, Mike Ash wrote:

In article ,
Gezellig wrote:

On Thu, 09 Jul 2009 17:44:28 -0500, Jim Logajan wrote:

http://www.ntsb.gov/ntsb/brief.asp?e...07X17184&key=1

How long after first impact should it take for the ELT to kick out a
call on frequency?

I assume pretty quickly, but if you're referring to the Fossett crash,
note that the NTSB report says the ELT was destroyed on impact.

I didn't catch the "on impact" only that it was destroyed. I guess they
judged that no signal meant destroyed on strike, must have been a hell
of a crash reading through the report.

Oops, you're right, I must have subconsciously assumed the "on impact".
Seems probable that the impact is what destroyed it, but it doesn't say
that, and it certainly could have happened later (e.g. in the fire). My
apologies.

That's what led to my question. I've never had the "opportunity" to set
off an ELT but I thought they were required to have a gyro or gravity or
some kind of ability to detect crash instantaneously and play out to
406.

CAP was combing the area by the NTSB with no report of transmission so I
suppose we can extrapolate that a severe enough impact can render the
ELT useless. I am guessing where the AC took the initial hit would be
important too in relation ot the positioning of the ELT in the AC.