What happens to fuel when a plane dumps it?

If the dumping occurs at least 5,000 feet above the ground in freezing temperatures, 98 percent of the fuel will evaporate before reaching the ground, according to the FAA. The fuel remaining in droplet form could cause local rain, but it would be spread over a wide area, minimizing the effects at the ground level.



People Also Ask

Fuel is usually discharged to reduce the aircraft's weight to facilitate making a safe landing. The following situations illustrate some conditions when fuel discharging is necessary.

MORE DETAILS

Airlines find that fuel dumping can actually be cheaper than not dumping in certain circumstances. But it's not something pilots do on a routine basis. We spoke with Alison Duquette, spokesperson for the Federal Aviation Administration (FAA), who assured us that it doesn't happen very often.

MORE DETAILS

Airplanes frequently depart the airport heavier than the maximum landing weight allowed – the threshold at which a given aircraft can sustain a very hard landing without damage. During a normal flight, the plan is to burn fuel so the plane's weight will below that number by the time it lands.

MORE DETAILS

In most cases, airlines only dump air in midair immediately before landing. They don't do it before or during takeoff, nor do they do it halfway through their flight. Rather, airlines may dump some of their airplane's excess fuel immediately before landing so that it lowers the weight of their aircraft.

MORE DETAILS

The maximum landing weight (MLW) is the maximum aircraft gross weight due to design or operational limitations at which an aircraft is permitted to land. The MLW is set in order to ensure safe landings; if an aircraft weighs too heavy during touchdown, it may suffer structural damage or even break apart upon landing.

MORE DETAILS

Q: Why do planes speed up before landing? The airplanes do not increase speed before landing. But when landing gear and flaps are set to landing position, they create a lot of aerodynamic drag. Therefore, engine power is increased to maintain the approach speed.

MORE DETAILS

When an airplane experiences less drag, it consumes less fuel. This relationship between speed and fuel consumption means that flying at a slightly slower speed can result in significant fuel savings for airlines, which in turn can lower operating costs and potentially reduce ticket prices for passengers.

MORE DETAILS

Yes. Some planes ? gliders ? don't have engines in the first place. When all engines fail in a powered plane fail, the pilots are often able to glide the plane to a safe landing, preferably at an airport, or if not that, a safe landing place, such as the Hudson River.

MORE DETAILS

Can a wide body airliner land with a full fuel tank? Yes! But it is safer to land an aircraft below its published MLW.

MORE DETAILS

Fuel dumps are instructed under FAA guidance to be done over remote or oceanic areas, or at an altitude at which the dumped fuel can atomize before reaching the ground, although such guidance may be bypassed in dire emergencies, according to the FAA.

MORE DETAILS

Since most twin jet airliners can meet these requirements, most aircraft of this type such as the Boeing 737 (all models), the DC-9/MD80/Boeing 717, the A320 family and various regional jet (RJ) aircraft do not have fuel dump systems installed.

MORE DETAILS

In this case, the aircraft will try to do it overland (not water) or away from populated areas, as it is the equivalent of dumping thousands of liters of petrol onto an urban area. The FAA mentions explicitly that any dumping can't occur under 2,000 feet.

MORE DETAILS