Fuel Jettison – Fuel Dumping

On March 23, 2018, a 60-year-old woman who was traveling by plane from Shanghai to New York suddenly gasped. She started having trouble breating. Interventing the passenger who started to lose consciousness was far beyond the responsibilities of the cabin crew. The captain knew there was only one thing to do to save him. And that is – “Pumping $20,000 worth of fuel into the sky” and then making an emergency landing. What do we mean? Let’s go further…

In this story, the plane later made an emergency landing in Alaska. The passenger was cured by being placed in a local hospital. So how did dumping $20,000 worth of jet fuel save his life? Let’s learn together.

What is Fuel Jettison ?

For some reasons, airplanes have to dump their fuel in the air during the flight. This process basically reduces the weight of the aircraft. Airplanes are designed to land under certain weights according to their types. If the plane lands heavily with fuel, it is possible that the plane will hit the ground hard and be damaged.

That day, this plane had an extra 5,000 gallons of fuel, which is roughly the weight of three elephants on landing. Therefore, landing with a full tank is quite risky.

Fuel Planning of a Flight

Before the planes take off, flight dispatchers, calculate the amount of fuel needed. Thus, information about how much fuel the pilot will burn at cruising altitude and how much the plane should weigh for a safe landing is in the hands of the captain. As you can see, the captain is equipped and prepared even in possible emergencies. However, a pilot does not prefer to dump fuel unless it is really necessary.

Fuel Jettison
Fuel Planning of a Flight

If the condition is critical, like the woman in this story in 2018, it would be the right choice to dump fuel. Otherwise, if the pilot has a little more time; Fuel, which is one of the highest cost item of airline companies, will not be thrown out of the air like this. Fuel jettison systems can dump thousands of dollars worth of fuel per second. An aircraft can be defueled in a short time, bringing it back to the desired maximum landing weight. It’s as easy as turning a switch in the cockpit. However, not every aircraft may have a fuel dumping system. Aircraft without a fuel dumping system burn fuel by holding at the safe route and altitude recommended by the air traffic controller.

Let’s go back to our planes that can dump fuel… With a simple command from the pilot in the cockpit, fuel flows from a system at the rear of the wing of the plane.

Fuel Dumping – Seperations

There are certain conditions/separations that airplanes must meet in case of a possible fuel dumping.

Fuel Jettison/ Fuel Dumping Separation Minima
Fuel Jettison/ Fuel Dumping Separation Minima

Air traffic controllers also advise pilots to the nearest suitable area. And pilots climb to a higher altitude, which allows the fuel to evaporate before it reaches the ground.

Fuel jettison/dumping into the atmosphere seems to be extremely rare as it is a ‘waste of money’ as we mentioned above. In addition, the negative impact of this process on the environment is also a situation that should be considered.

According to research by British airlines, it is estimated that 0.01% of the fuel used by the aviation industry is wasted each year. If that number is still valid today, it means that about 2 million gallons of fuel have been thrown away by airlines in America alone. The same studies also argue that the dumped jet fuel must evaporate before hitting the ground, but Boeing has claimed in recent years that even if the fuel evaporates, it still hangs in the atmosphere. Boeing also made claims in the same study that the fuel would eventually reach the ground, or even be carried by the wind and become a smoke component. Different theses are still being produced and discussed on this subject.