"Ron" wrote in message
...
Arfa Daily wrote:
"Ron" wrote in message
...
Arfa Daily wrote:
Seems that today, an Air France Airbus A330 en route from Rio to
Paris with
238 people on board, has gone down without warning over the Atlantic.
Hard
to see what the pilot might have done wrong with the thing at 38000
ft in
the cruise ...

Apparently, it disappeared off African trans-atlantic ATC radar, at
around
3am, our time.

This is not instilling a lot of confidence in me, regarding flying on
one of
these things in October, instead of my usual Boeing ... :-|

Electrical and turbulence problems reported. Aircraft was sending
distress signals so it may have made a decent ditch. Air France's last
air disaster was the Concorde in 2000.

I've flown the 320-100 several times and the Mulhouse crash never
entered my mind. We actually had a 5 hour delay one time after a
hydraulic pump failed on the ground and had to be replaced.

I wouldn't worry about the 330 considering the number of those things
in the air at any given time and it's wonderful track record.
Yeah, I know what you're saying. It just bothers me a little that on
say a 747, the driver has got a triple redundancy control system which
hydraulically links his yoke and pedals directly to the control
surfaces, and a robot driver that can be thoroughly switched off, such
that in an unusual set of circumstances, a quick-thinking and
experienced guy sitting behind those controls, might be able to recover
a potentially catastrophic situation by thinking outside the box, and
doing something which maybe puts the airframe outside of the 'safe'
envelope. From what I can understand of the FBW systems, they are never
going to allow you to do this, and in the event of a total electrical
systems collapse, your little joystick, and the computer(s) that it's
connected to, are not going to be of any use to control the aircraft,
anyway.

My pilot friend rang me yesterday when all this was going down
(honestly, no pun intended). He felt that there had to be more to it
than just flying into a storm. He says that in general, if lightning
hits an aluminium-bodied plane, it tends to pass around the outside,
and re-discharge and carry on its way from the opposite side or
wherever. He questioned whether the same would happen on a carbon
composite bodied plane, as the A330 apparently is, or whether the
higher electrical resistance of such a material, would cause the
lightning to 'stick around' as it were, and just fry the internal
systems, or even heat the material to the point where it just exploded.
He reckons that unless there was an absolutely catastrophic failure of
the airframe, a distress signal should have been able to be broadcast
almost all the way down, as the last voice transmitter is battery
powered to ensure that it can still operate, even in the event of a
catastrophic electrical or systems failure. Sobering thoughts ...
From reading the boards, it appears that, rather than flowing arond the
outside of the aircraft, lightning is more inclined to punch holes right
through composite skins, thereby getting into the metalwork and wiring.

Ron(UK)

So, perhaps not the best choice of material to make a long haul aircraft
from, given that it is going to fly to areas of the world where
thunderstorms are prevalent, and at cruising altitudes where it is well
up amongst the crap, as it were.

I have actually flown in and out of both Orlando and Las Vegas, with
thunderstorms in the area, without giving them a second thought. But then
that was in a nice 747 aluminium cigar tube ...

If it is true that CC skins are not good in areas of electrical storm
activity, I'm sure pilots regularly flying such planes, must be aware of
this, so if the weather radar on this flight showed that he was heading
into bad air and storms, I wonder why he didn't go around it, or see if
it was possible to climb above the worst of it ? I understand that
thunderheads can extend above the maximum ceiling of airliners, but I
would have thought that there might have been a 'way through' between
cells ? Fuel constraints maybe ? Looking on a map, the path from Rio to
Paris looks awfully long for a plane of this size.

There`s a lot of stuff, some useful some 'not so' on the PPrune boards
about this accident. Many of the posts are from people who fly these birds
everyday for a living, it`s a good read.


BTW, is that Ron ex LVA ? If so, you haven't by any chance got a
schematic set for a Warwick Sweet 25.1, have you ? Or anyone else reading
this ? Warwick have refused to even acknowledge requests for assistance,
let alone supply info.


Well LVA is still alive and well, I just don't do many repairs any more,
I`m concentrating more on live sound production. Sorry Arfa I don`t have a
diag for that amp.

Ron(UK)

No sweat. I've found the problem now. Some moron had pinched a wire to the
fans under a board mounting pillar when reassembling after some previous
repair. It had nicked the insulation, resulting in an intermittent short to
the metal pillar. Very odd symptoms this caused. Sometimes, when you flicked
the "ground lift" switch on the back panel, the fans would start up at full
chat, and a sound that can best be described as a drone pipe on a set of
bagpipes, ramped up as the fans ran up. Very odd indeed.

So, where do I find this PPrune board ?

Arfa