Re: Swissair MD-11 (SR 111, JFK-GVA) crash off Nova Scotia

Date:         10 Sep 98 03:04:25 
From:         "S.L." <look@the.sig>
Organization: Applied Research Laboratories - The University of Texas at Austin
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Pete Mellor wrote:
>
>(The CVR is still to be located, although signals from
>it have been detected by sonar.)

???
Do CVR's have acoustic beacons or pingers? I assume they have RF
beacons, but I didn't know they had pingers.

> Unfortunately, the DFDR was found to have stopped recording at
> the point at which the aircraft descended below 10,000 feet,
> i.e., it does not cover the last 6 minutes of the flight, during
> which the behaviour of the plane is the most mysterious!
> Investigators speculate that this is due to a total loss of
> power at that time.

Do DFDR's and CVR's not have internal backup batteries to continue
powering the recorders for a while after a power failure? Lithium cells
with service lives of 10 years or more are common as dirt (in personal
computers and other electronic systems) now, so this shouldn't pose a
huge maintenance problem

--
Stephen Lacker
Applied Research Laboratories, The University of Texas at Austin
slacker@arlut.utexxas.edu (Remove the extra 'x' to mail me)