[SystemSafety] MH370

Tue Mar 11 22:19:52 CET 2014

Just to add that large passenger aircraft do have onboard emergency locator
transponders, a mix of fixed (airframe mounted and possibly g switched) and
portable (cabin and raft located). Over water a portable (buoy style)
maritime ELT is carried onboard but its down to the crew to deploy it.
Unfortunately if the maritime ELT goes to the bottom with the aircraft
while it may activate, the radio signal is unlikely to get through.

Sonar pingers are fitted to FDR and CVR, but with underwater acoustics you
need to get within range, on the order of a couple of km, and just because
you can hear them doesn't necessarily mean you can locate them easily;
currents, ambient noise, thermoclines, turbidity, terrain shadowing or
wreckage can make the job very difficult.

Matthew Squair

MIEAust, CPEng
Mob: +61 488770655
Email; Mattsquair at gmail.com
Web: http://criticaluncertainties.com

On 11 Mar 2014, at 11:41 pm, David Crocker <dcrocker at eschertech.com> wrote:

 Large commercial aircraft already transmit their position and other
parameters to other aircraft, via mode S extended squitter, and in some
areas (some USA airspace AFAIR) by ADSB over VHF data link. If aircraft
recorded some of the data they received from other aircraft, then there
would be the possibility of determining the last position of an aircraft
before catastrophic failure from the recordings stored by other aircraft in
the vicinity, even in areas where there is no radar cover. This could speed
up the recovery of the FDR and CVR.

Whether this would be viable depends on the range at which data can be
received from other aircraft, and the density of aircraft in the airspace.

David Crocker, Escher Technologies Ltd.http://www.eschertech.com
Tel. +44 (0)20 8144 3265 or +44 (0)7977 211486

On 11/03/2014 10:07, Chris Hills wrote:

  Memory may be cheap but an EPIRB is self-contained.  It needs no external
connections or wiring.  No point in adding any complexity (weight, power
requirements, connectors, wiring and systems in the aircraft etc).    With
no connections to the aircraft wiring or power supply the reto fitting is
far easier, cheaper and the system is more cost effective.

As it is only going to be needed for locating aircraft that have sunk it
only needs to be on a mount at activates  at  a depth of say  10 metres and
a life of 24 or 48 hours.  24 might be a bit short if it is in the middle
of nowhere and  the weather is bad.

Once you have found the EPIRB the aircraft will not be far away compared to
the current search area and that for AF447. Then you can recover the data
from the FDR and CVR.

*From:* Matthew Squair [mailto:mattsquair at gmail.com <mattsquair at gmail.com>]

Yep, like an EPIRB. But if you're going to do that, well memory is cheap.

Matthew Squair

MIEAust, CPEng

Mob: +61 488770655

Email; Mattsquair at gmail.com

Web: http://criticaluncertainties.com

On 11 Mar 2014, at 8:13 pm, Chris Hills <safetyyork at phaedsys.com> wrote:

 Actually you don't need a detachable FDR or CVR.  All you need is a
detachable simple distress beacon with a life of 48 hours. If you can find
that it would narrow the search field to say, a 10 mile radius,   rather
than thousands of square miles.  Then you can find the wreckage and the
black boxes far faster.

A small distress beacon would be smaller in size, mass and complexity, very
cheap (comparatively) and easier to mount.

Regards

   Chris

*From:* systemsafety-bounces at lists.techfak.uni-bielefeld.de [
mailto:systemsafety-bounces at lists.techfak.uni-bielefeld.de<systemsafety-bounces at lists.techfak.uni-bielefeld.de>]
*On Behalf Of *Matthew Squair
*Sent:* 10 March 2014 23:28
*To:* Peter Bernard Ladkin
*Cc:* systemsafety at lists.techfak.uni-bielefeld.de
*Subject:* Re: [SystemSafety] MH370

Sure, but over the years there have also been a number of lost at sea
accidents where either the FDR or CVR were not recovered or were recovered
damaged. Dave Warren's original proposal was aimed squarely at that problem
and was for a foam cored blister pack with a simple wire spool recorder and
die pack, the concept being that it would be mounted on the external
fuselage (around the tail) and popped off in an explosion or impact induced
hull over-pressure.

On Tue, Mar 11, 2014 at 9:07 AM, Peter Bernard Ladkin <
ladkin at rvs.uni-bielefeld.de> wrote:

> On 10 Mar 2014, at 22:17, Matthew Squair <mattsquair at gmail.com> wrote:
>
> Absolutely, nothing is perfect. But would I prefer an alternate to months
of trawling the abyssal plain with a side scanning sonar? You betcha.
Especially if it's a very, very cheap alternative.

In the last twenty years, there are just two cases of lost-at-sea I can
think of in which evidence from the hull was *not* required in addition to
FDR data to determine cause. There are five cases in which in-air
disintegration or burning, which are not identifiable from FDR data,
initiated the hull loss, and there is one further case in which physical
evidence was required to show there was no anomaly (that it was, in effect,
murder/suicide). Two against six isn't a persuasive ratio.

I can go through the records to make this definitive rather than "I can
think of", if necessary.

The result of a cost-benefit analysis, even for the past, let alone for
conceivable future cases, is not at all evident to me.

PBL

Prof. Peter Bernard Ladkin, University of Bielefeld and Causalis Limited

-- 

*Matthew Squair*

MIEAust CPEng

Mob: +61 488770655

Email: MattSquair at gmail.com

Website: www.criticaluncertainties.com <http://criticaluncertainties.com/>

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