Nugget of Knowledge: Fuel Dumping by Airplanes

I always found the following act by an air-plane very very peculiar… They, at times,  just spill their fuel in mid air :-/ I wondered why would someone just waste aircraft fuel which is rather costly?


Source :


Being brought up in military environment I had also seen the same at air-shows wherein the fighter planes would drop off their fuel tanks just before pulling dangerous manoeuvres… A little thought made me believe that it must be due to the fact that dropping off fuel tanks must be making the air-craft lighter and easier to manoeuvre. But further reading on the web gave me a lot more reasons 🙂

The most important reason is not so obvious. I found out that fighter-pilots shed off fuel before performing dangerous stunts is to avoid a blasts or a violent fire in case they loose control and crash land.


However, in case of commercial flights (like in the gif above) the case is a little different. They have two different types of weight limits: Maximum take-off weight and Maximum landing weight. The latter is always considerably less than the former for a reason that during landing the plane hits the deck and if this hit is not smooth then plane may keep bouncing and even bounce off the runway! :-/

Usually this doesn’t pose a big problem because airlines implement a good fuel management. They calculate how much fuel would a plane burn in journey and put in fuel accordingly. So generally the plane is well within the Minimum landing weight limit at the time of landing. But in case of emergency landings just after take-off or mid-way the journey this assumption doesn’t hold good. So even they dump fuel in mid air to make it safe to land the plane…

Interesting right? 🙂