6
$\begingroup$

Can anyone tell me how aircraft such as jet fighters and stunt planes design the fuel tank vent system to prevent fuel leaking through the vents when performing aerobatics, 360 flips and complex maneuvers? Surely jet fighters don't just let it leak out?

$\endgroup$
  • 1
    $\begingroup$ Why are fuel tanks vented? Is my car tank vented too? $\endgroup$ – user7241 Dec 26 '17 at 20:03
  • 1
    $\begingroup$ @jjack -- the tank vents allow air to come into the tank to replace the fuel that's pulled out by the fuel pump. $\endgroup$ – Pete Becker Dec 26 '17 at 20:10
  • 1
    $\begingroup$ @PeteBecker Why is this done? $\endgroup$ – user7241 Dec 26 '17 at 20:11
  • 1
    $\begingroup$ Vents are also used to remove fuel vapours and prevent the fuel tank from pressurising in cars the vent typically runs to a charcoal canister to reclaim fuel. $\endgroup$ – Chris James Dec 26 '17 at 20:14
  • 1
    $\begingroup$ @jjack because otherwise the vacuum that developed in the tank would suck the fuel back into the tank with more force than the fuel pump sucked it out, the pump would stop pumping, and the engine would stop engineing. And yes, your car has a venting system too. $\endgroup$ – hobbs Dec 27 '17 at 6:48
5
$\begingroup$

There are 3 common solutions,

1) do nothing, unless the airplane is flown for an extended period of time inverted, there will be no appreciable vacuum created from fuel use and the vent is so small that there will not be appreciable fuel loss.

2) point the vent into the slipstream giving a ram air effect.

3) use two vent tubes (can be mounted either top & bottom or same side), at least one extends to opposite side of the tank.

enter image description here This picture is for RC or drone aircraft but the same principle is used for full scale aircraft.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.