Have you ever looked up into the sky and seen an aircraft passing overhead with two lines of smoke tailing its path? If you have, then you are going to get to know what it is. Yes, the fog is—in aviation industry—called as fuel dumping.
Anthony Brickhouse, an Associate Professor at Embry-Riddle Aeronautical University, said to put it simply, fuel dumping is a process an aircraft takes to lose some weight before it lands. For a longer explanation, fuel dumping is when aircraft drops thousand gallons of their fuel, or kerosene, into the atmosphere some time before it lands to the ground.
The need to dump some oil relies on the fact that planes are designed to land at certain weights. Thus, a heavier plane carrying a full tank fuel is likely to hit the ground hard and get damaged. According to Brickhouse, most flights do not land with a full tank nor fly with a full thank either. He explained that before taking off, every aircraft will get through a procedure of fuel calculation by a flight planner or engineer. This is intended to avoid the need for fuel dumping.
So, why would an aircraft even dump its fuel?
The first and sole reason an aircraft to dump some fuel is for emergency only. Yeah, the consideration, from the carrier’s side, is it is a wasting money. Should you have to know, fuel dumping system in an aircraft can dump thousand gallons of fuel in one second. And that is likely worth ten of thousand dollars. Other reason comes from Environmental Protection Agency, stating that fuel dumping may affect the atmosphere.
The Federal Aviation Administration (FAA) has noted some regulations that a plane has to take if it wants to dump its fuel. They have to be
- at least 2,000 feet;
- at least five miles from other aircraft; and
- away from populated areas and bodies of water.
Fuel dumping, though, is not the safest choice to take for emergency needed—as it has its own pros and cons. However, it is pilot’s decision to do it or not before the landing. And maybe the plane dumping some fuel you were seeing the other day was in emergency state.
