Ext Tank Dump

[tinyclark]

I have a question, and what I got for a response from two F.E.s here at Moody, I'm not sure they understood. Or maybe I don't understand.

When the external tank dump switches are placed to DUMP, the voltage which operates the TANK EMPTY lights is removed from the circuit.

How do you know when to shut the pumps(s) off? Do you just use the pressure reading? Seems kind of dumb to me, but I'm just a pointy head.

[Dan Wilson]

Basically you just use the fuel quantity indicator and when it gets to zero or close enough and stops moving you shut it off. If the indicator is bad you just make sure you start dumping that tank first so you can verify the fuel coming out the dump mast prior to dumping any other tanks.

You really wont see diddly on the pressure indicator when your dumping, pipes too big and no real chance to build up pressure.

Dan

[agarrett]

How do you know when to shut the pumps(s) off?

Just before the crash or short final.

If the indicator is bad you just make sure you start dumping that tank first so you can verify the fuel coming out the dump mast prior to dumping any other tanks.Dan

Alternate method is the turn on the pump for the tank with the INOP gage, watch the pressure start to build, open the "X" valves, watch the pressure drop, then hit the other dump pumps. This would come in handy if for some reason you couldn’t verify it visually in a timely manor. This, of course, won't work if your "X" valves are already open.

You really wont see diddly on the pressure indicator when your dumping, pipes too big and no real chance to build up pressure.Dan

This is why the lights wouldn’t do you any good anyway. They would be staring you in the face the whole time the pumps were on.

I wish I had the money it cost for all the fuel that Iv'e dumped over the years.