I checked CARs, as well as google searches, youtube vids, etc. on fuel dumping systems and I cannot find it anywhere, does anybody know or have a source for this question?

Fuel dumping systems usually incorporate:

A) a flowmeter in the dump line to allow calculation of the quantity of fuel dumping in a particular period of time
B) an electric pump in each tank to accelerate the rate of dumping
C) float operated shutoff valves in all tanks to accelerate the rate of dumping
D) provisions in the main tanks to prevent dumping all the fuel

 

You don't even need to know the system to find the right answer. Which is the one thing on that list that you really, really don't want to do?

A 727 or 747 flight manual (the two places I've seen the answer) would be the official source.

 

Do we have another reporter wannabe trolling for info?

 

In reality, it is E: None of the above. It typically comes out of the center tank (if installed) and also the fuel dumping system (if installed) is just to assist to help get down to max landing weight if time permits. If no fuel dump and time permits (like on most airplanes... all narrowbodies and a handful of widebodies), then we'll loiter around or go ahead and land if it's not that bad of a situation, otherwise we'll burn off gas flying around. If we are among the handful of widebody planes equipped with fuel dump and can justify the time hanging around to dump fuel, then we will.

 

727 dumps out of 1, 2 and 3. Cruel check airmen would fail a pump in a wing tank to make the F/E work harder, simple solution was to turn off a pump in the opposite tank.

744 dumps out of 2 and 3, 1 and 4 transfer into 2 and 3 during the process.

The 767 just dumps out of the center.

It used to be if here was more than a 5 percent difference between max T/O and max landing, you needed a fuel dump system. Now the Feds say as long as the plane can meet landing climb and approach climb limits after a 15 minute fuel burn from max T/O you don't need a dump system.

 

Thanks for the replies. The thing that confuses me about the question is that I'm seeing people say more than one of these answers can occur, but there is only one correct answer, however, the aeroplane type is not specified in the question.

 

Twin Wasp,

IIRC, couldn't the FE dump all of the fuel on the B727?

GF

 

D

Page 14-6 and 14-7 in this linked document, I didn't check the bibliography, for chapter and verse, but the reference will be CFR 14 Part 25

https://www.faa.gov/regulations_poli...a/ama_ch14.pdf

 

Apparently not. Either that, or the B-727 is not a narrowbody.

All those hours in the B-727 sims running the dump panel while I was cranking the gear down and protecting essential must have been a figment of my imagination.

I often wonder how many aircraft types one must be familiar with before he can authoritatively proclaim how most, or all, or even typical aircraft systems behave. . . . .

Title 14 CFR §25.1001 Fuel jettisoning system outlines the FAA standards for the system. In that regulation, there is no specific requirement for a flowmeter, an electric pump, or a float operated shutoff valve -- scratch A, B, & C. Subparagraph (g) states, "The fuel jettisoning valve must be designed to allow flight personnel to close the valve during any part of the jettisoning operation." I'd put my money on D.






.

 

Galaxy,

Everyone called it a standpipe but that would have been too simple. There is a float assembly in each tank which "should" stop the dump at 3500 pounds in each tank which Boeing figured would give you 45 minutes in the pattern. There were notes in all the training materials at AA for F/Es to expect this system to fail in the sim if the Captain said to "Dump to the standpipes."

RMP,

If you're dumping, you're having a bad day. Do you really want to add running out of fuel on top of that?

Some planes do have override pumps that work during dump but some planes just use the regular pumps.

What good is a flow meter in the dump line going to do, you're looking for a number on the fuel panel if if you don't have a "fuel remaining" setting on the dump control.

How a shutoff valve would accelerate the dump is, ah, a CNN talking head answer.