Do passenger planes dump fuel before landing?

While fuel dumps don't happen every day, they're also not uncommon. Nor do they usually represent a major emergency. In fact if an aircraft is taking the time to dump fuel before landing, that's likely an indication that the issue forcing the plane to land is serious but not critical.



Passenger planes do not dump fuel during a routine flight. Fuel jettisoning is an emergency procedure used when an aircraft must land shortly after takeoff—due to a medical emergency or technical issue—while still carrying a heavy load of fuel. Planes have a "Maximum Takeoff Weight" (MTOW) and a "Maximum Landing Weight" (MLW). If a plane lands while too heavy, it risks structural damage to the landing gear. Large wide-body aircraft like the Boeing 747 or Airbus A380 are equipped with jettison systems to spray fuel from wing nozzles at high altitudes (>6,000 feet), where it evaporates before reaching the ground. However, most narrow-body planes, like the Boeing 737 or Airbus A320, lack these systems and must instead circle to burn off fuel or perform a "heavy landing" inspection if the situation is critical.

People Also Ask

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

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

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

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

If fuel dumping is ever required (a very rare thing) - it's usually dumped over the sea or in unpopulated areas, and above 5000' so it completely evaporated and does not hit the ground.

MORE DETAILS

In these cases, the airplane may arrive at the landing airport at a weight considerably above the maximum design landing weight. The pilot must then decide whether to reduce the weight prior to landing or land overweight. The weight can be reduced either by holding to burn off fuel or by jettisoning fuel.

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

For example, with a glide ratio of 15:1, a Boeing 747-200 can glide for 150 kilometres (93 mi; 81 nmi) from a cruising altitude of 10,000 metres (33,000 ft).

MORE DETAILS

In commercial aviation fuel is dumped rarely. Only if the aircraft is taking off above max landing weight and an emergency takes place shortly after takeoff would a commercial aircraft be required to dump fuel.

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