On Fri, 16 Jan 2009 10:24:45 -0800 (PST), wrote:

On Jan 16, 12:33Â*pm, Kurt Ullman wrote:
In article ,
Â*Smitty Two wrote:





In article
,
Â*Kurt Ullman wrote:

In article ,
Â*Smitty Two wrote:

It is only "considered a crash" by the media. Pilots call that an
"off-field landing." A plane crashes when structural failure or pilot
error causes the plane to no longer be under the control of the pilot.
This was not the case, here.

Â*Wouldn't the engines flying apart be considered structural failure and
turning an airplane into a glider would seem to suggest the pilot isn;t
in control (serious question, honestly)

No. I believe structural failure involves the loss of an airfoil (wing,
horizontal stabilizer, or vertical stabilizer) or the loss of one of the
control surfaces attached to those airfoils (aileron, elevator, or
rudder) which are the movable surfaces used to control the roll, pitch,
and yaw axes.

Â* Interesting. Thanks for the reply.



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Yep, airplanes are still controlable without power. In the case of
the Boeing 757, for example, they have a built in turbine in the
bottom of the plane. In the event the plane loses all power, the
turbine drops down to use wind power to power the essential hydraulics
and electronics. That system was used early on in the life of the
757, when Air Canada managed to run one dry on a commercial flight.
The ex military pilot knew of a closed military air base and they
managed to glide many miles, maybe 50 or so and land successfully.
In case you're wondering, they ran it dry because one fuel gauge
wasnt' operating correctly. The pilots and ground crew concluded it
was legal to fly as long as they dipped the fuel tank. Which they
did, but in converting from metric to english or vice versa, they blew
it and grossly miscalculated the fuel on board.

In the case of this A320, not sure what powered the hydraulics, etc
after both engines failed. But I would guess it would have been an
aux power unit, which is essentially a small fuel powered turbine that
is used to provide starting power, etc.


Remember the plane that ran out of fuel over the Atlantic and landed
on an island off the coast of Africa a few years ago? The glide COULD
have been stretched to reach the African mainland with no trouble -
but the airport on the island was familiar to the pilot and well
equipped and located.