Me and my brother are at a loss, we understand the basics of how the upside down thing works, but how does the engine get fuel when the tank is turned around, is it a vacoom and how would that work or is the intake from the tank in the back of the it, so the fuel is forced into the engine? Thanks.
In: Engineering
Lots of partially correct answers here along with lots of wrong answers.
Most fighter jets don’t have a floating fuel pickup tube. Their max fuel consumption is way too fast for a floating fuel pickup tube to work, it would just collapse. They have feed tanks that are always filled from other fuel tanks throughout the aircraft. When the only fuel remaining in your tanks is just your feed tank, you better have the runway in sight unless you want to run your emergency checklist for fuel starvation.
Some fighters like the A-10 and F-15 have fuel foam lining their tanks; it’s open cell foam that looks like a sponge with very large holes in it that keeps the fuel from sloshing around too much while others have baffles in them to do the same thing.
Every aircraft, (fighter, aerobatic, passenger) doesn’t like pulling negative Gs, a full [aileron roll is a 1-g maneuver](https://www.youtube.com/watch?v=K7PPfm3-e9o), even while the aircraft is upside down, the fuel, the pilot and the aircraft are experiencing 1-g. The fuel is still at the “bottom” of the fuel tank. Only if the pilot stops at the top of the roll will gravity pull the fuel toward earth. This will lead to fuel starvation in most non-aerobatic aircraft.
Finally, every aircraft I’ve worked on will have an extensive checklist which includes replacing the engine if 0gs or less was experienced for over 1 minute.
Source: 20 year aircraft maintenance tech.
Latest Answers