Q. On my flight yesterday, the pilot came on the PA about halfway through the flight and announced that the plane was doing very well with little head winds so the speed flaps (or whatever they are called) on the wings would be up for the rest of the flight. He said they needed to burn off some excess fuel before we landed. Why is this? Why would they intentionally waste fuel?
A. Sounds pretty crazy with the high gas prices these days that airlines would simply dump fuel, but it is indeed true. It all has to do with weight. Airplanes have a maximum take-off weight and a maximum landing weight. If the plane lands too heavy, it could be unsafe and do damage to the plane. Dumping passengers or bags just wouldn't fly (no pun intended), so the aircraft dumps fuel. Not all aircraft are able to dump fuel, so they would simply burn it by circling around until they reach a safe landing weight. This is not a normal occurrence. It is usually done during unscheduled landings, such as emergencies, when the aircraft needs to land immediately, thus not burning the fuel it would have normally used en route. In your case, the little head wind resulted in the plane's "miles per gallon" being more efficient and it needed to burn more fuel once it was in range of your destination in order to reach a safe landing weight.