Fuel dump

As a rule, aircraft are not allowed to jettison or dump fuel in flight. However, an exception is made for safety reasons.


It is the captain who takes the decision to jettison fuel. In some cases this is because the aircraft exceeds its maximum landing weight. That is often lower than its weight at take-off, with fuel accounting for the difference.


In many cases, aircraft making precautionary landings have only just taken off. Because of this, they may have too much fuel on board to be able to land safely. Some types are able to jettison fuel, others are not. The latter have to fly circuits over a designated area until they have burnt enough fuel to reach their maximum landing weight.


When a pilot reports that he or she needs to jettison fuel, the air traffic controller asks whether that has to be done immediately and how long it will take. The minimum altitude at which fuel can be discharged is 7000 feet, or just over two kilometres, unless safety reasons dictate otherwise. If the fuel has to be jettisoned immediately, the air traffic controller makes sure that neither the aircraft dumping it nor any other planes with a planned route in the area come into contact with it. The discharge zone remains closed to all traffic for at least fifteen minutes.


If the situation is less urgent, but fuel still has to be jettisoned in order to be able to land safely, the air traffic controller instructs the pilot to dump it over the North Sea.