NW_Pilot's Trans-Atlantic Flight -- All the scary details...

"Larry Dighera" wrote in message
...
On Mon, 02 Oct 2006 19:32:15 GMT, "Allen"
wrote in :

Twin Cessna's
are the same way; if you switch to the aux tanks before burning a certain
amount out of the mains (90 minutes for the large aux tanks) the mains
will
overfill and vent overboard before the aux tanks are empty.

Are you saying that Cessna designed the fuel system that way, and the
FAA certified it? Or are you referring to a ferry tank?

It makes you wonder if the FAA would certify kinking the fuel line
instead of providing a valve to shut off fuel flow. :-)


I should have said the "tip tank" Twin Cessnas. Cessna designed it that
way. Fuel injected cars do the same thing but have only one tank to return
the fuel to so it is not a problem. If you wanted to return the excess fuel
to the same tank it was drawn from you would need two sets of directional
valves; one on the supply line and another on the return line that were
synched to each other. It is much easier just to tell the pilot to burn 90
minutes out of the mains before switching to the aux's.

Allen

On Tue, 03 Oct 2006 01:40:46 GMT, "Allen"
wrote in :

I should have said the "tip tank" Twin Cessnas. Cessna designed it that
way. If you wanted to return the excess fuel to the same tank it was drawn
from you would need two sets of directional valves; one on the supply line
and another on the return line that were synched to each other.

What would prevent plumbing the fuel return line into the top of all
fuel tanks above the fuel level, so that the returning fuel would be
able to fill whatever tank space was available at the time? There
would be the added cost of labor and materials, and the added weight,
but the hidden hazard would be eliminated.

It is much easier just to tell the pilot to burn 90
minutes out of the mains before switching to the aux's.

It would seem a placard would be more prudent.

Larry Dighera schrieb:

What would prevent plumbing the fuel return line into the top of all
fuel tanks above the fuel level, so that the returning fuel would be
able to fill whatever tank space was available at the time?

This would prevent an informed tank management.

It is much easier just to tell the pilot to burn 90
minutes out of the mains before switching to the aux's.

It would seem a placard would be more prudent.

If this simple instruction is already too complicated for a pilot...

Stefan

On Tue, 03 Oct 2006 12:47:45 +0200, Stefan
wrote in :


It would seem a placard would be more prudent.

If this simple instruction is already too complicated for a pilot...

It's more a matter of the possibility of someone failing to inform the
pilot of this hidden hazard. A placard is more foolproof than relying
on the spoken word or a phrase buried in the POH.

Larry Dighera schrieb:

It would seem a placard would be more prudent.

If this simple instruction is already too complicated for a pilot...

It's more a matter of the possibility of someone failing to inform the
pilot of this hidden hazard. A placard is more foolproof than relying
on the spoken word or a phrase buried in the POH.

Ok. So let's forget the POHs and replace them with a bunch of placards.
Reminds me of my monitor full of post-it stickers.

Stefan

Stefan wrote:
Larry Dighera schrieb:

It would seem a placard would be more prudent.

If this simple instruction is already too complicated for a pilot...

It's more a matter of the possibility of someone failing to inform the
pilot of this hidden hazard. A placard is more foolproof than relying
on the spoken word or a phrase buried in the POH.

Ok. So let's forget the POHs and replace them with a bunch of placards.
Reminds me of my monitor full of post-it stickers.

Stefan

Hey, as long as the cleaning people don't come through and remove them...