Fuel Dumping” is the term generally given to when an aircraft disposes fuel mid-air prior to landing. This often occurs when a plane is forced to make a landing short of its intended destination to lighten the aircraft’s weight.
However, there is another more secretive meaning to the term “Fuel Dumping”. It involves intentionally pairing two separate flights on the same airfare ticket in the hope that the fuel surcharge component of the main, more-expensive flight is either partially or fully dumped/eliminated. Have a read of this previous blog post to gain a better understanding of the fuel surcharge component and why it exists.
http://www.secretflying.com/