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?
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.