Can commercial airplanes 'dump fuel'?

Discussion in 'Highly Technical' started by tommywishbone, Sep 21, 2005.

  1. tommywishbone

    tommywishbone Platinum Member

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    I think the fuel tanks are in the wings and the engines are close by, sounds dangerous to pour fuel so close to jet engines. How does a 'fuel dump' work and can all commercial airlines do it? Thanks.
     
  2. ZeroNine8

    ZeroNine8 Member

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    it's quite easy to run a pipe from the fuel tanks to wherever a safe release location might be, whether at the wingtips or at the rear of the plane, etc. The only thing you've got to make sure of is that you don't release it in front of some ignition source, which is pretty easy to do at 300+ mph.
     
  3. Markbnj

    Markbnj Elite Member <br>Moderator Emeritus
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    Yes, there is a Jet Blue A320 dumping fuel out off the California coast right now.
     
  4. Gibsons

    Gibsons Lifer

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    burning it off by circling, not dumping. Apparently the A320s don't have the ability to dump, unlike most other airliners (what I've heard, I'm no expert).
     
  5. The Boston Dangler

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    I thought all commercial planes can dump fuel, in case of emergency "landings".
     
  6. ScottMac

    ScottMac Moderator<br>Networking<br>Elite member

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    Many airplanes over gross weight of 12, 500 poinds have restrictions relating to "Take Off Weight" and "Landing Weight."

    Most commercial aircraft (and military aircraft) have some facility for dumping fuel ... generally to cover emergency situations where they would otherwise have to land heavier than the designed Max landing weight.

    Most commercial aircraft have many fuel tanks located all over the aircraft: one or more tanks in the wings, and in two or three locations in the belly. The fuel is pumped from tank to tank throughout the flight to help keep the plane in trim.

    Dumping fuel is discouraged, but it's not really that big of a deal. At those speeds, it's pretty much atomized and diluted in the clear air (same thing if they dumped the bathroom tanks).

    There was a trick the F111 drivers used to do .... they dump some fuel in the clouds, then hit the afterburner to ignite it .... it was alledged to be something to behold ... an amazing sight ..... scares the hell out of a pursuer too.

    FWIW

    Scott
     
  7. JustAnAverageGuy

    JustAnAverageGuy Diamond Member

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    Video? :camera: :D
     
  8. BespinReactorShaft

    BespinReactorShaft Diamond Member

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    Not sure if this is related to what he meant:

    http://images.google.com/images?svnum=1...safe=off&q=F-111+fuel+dump&btnG=Search

    But HOLY FLAMING SKYFARTS! :Q
     
  9. Markbnj

    Markbnj Elite Member <br>Moderator Emeritus
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    [burning it off by circling, not dumping. ]

    Yeah, apparently CNN had it wrong.
     
  10. mooglekit

    mooglekit Senior member

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    Yeah, I watched a bunch of that yesterday on a live feed, and they thought there was dumping, but the 320 isn't capable of dumping. They brought on an aviation expert and apparently only the larger commerical airliners (think 747) have the ability to dump fuel, smaller ones simply depend on burning it off in-flight like in the incident yesterday...crazy stuff.

    BTW, props to the pilots of that plane, PERFECT landing with the front gear twisted around 90 degrees...nice work!
     
  11. imported_Dimicron

    imported_Dimicron Senior member

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    Agreed! Those pilots did a great job on that landing. Was cool to see it on CNN. Not something I'd want to try.

    :beer:

     
  12. The Boston Dangler

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    Even if they could have dumped the gas, I think they would have tried to burn it off for a couple hours while trying to get the gear fixed. What's really freaky is the people on the plane watching TV. When the "experts" were predicting the worst, that's when the crew shut off the TVs.
     
  13. George Powell

    George Powell Golden Member

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    Here is a picture of an Airbus A340 while dumping fuel.

    A340-600 dumping fuel

    The reason for fuel dumping is to reduce the weight of an aircraft to that of its maximum landing weight. This can sometimes mean dumping over 100 tonnes on the 747.

    The jettison nozzles, usually one on each wing (although) this depends on the type of aircraft are set away from the engines and the exhaust from the engines.
     
  14. f95toli

    f95toli Golden Member

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    747 and other large airplanes dump fuel quite often. As George Powell writes it is done to reduce the weight of the plane.
    Every time a transatlantic flight with a 747 is aborted because of technical problems they have to dump fuel before they can land again, this happens quite often.

    A few years ago I was on a flight from Amsterdam to Houston, about 10 minutes after take-off the pilot told us that they had a problem with one of the flight intruments (a problem with the "symbol generator", I still don't know what that is).
    They dumped some fuel, landed (just an ordinary, normal, landing), reparied the instrument, refueled and then we took off again (we spent about two hours on the ground while they were looking for a new symbol generator). Nothing dramatic.

     
  15. George Powell

    George Powell Golden Member

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    You say quite often but in actual fact is very rare these days compared with years gone by. Aircraft are much more reliable and have huge amounts of system redundancy that allows them to continue safely to their destination. Even an engine failure is not enough to always warrant a diversion. It seems most diversions are the result of medical emergencies or severly disruptive passengers who threaten the safety of the aircraft and/or fellow passengers.