"Aircraft without fuel dumping capability are certified for overweight landing if necessary. Should an event occur requiring an immediate return for landing, the crew executes the landing and notes in the maintenance log that an overweight landing was made. The maintenance department conducts an inspection, and if there was no damage the airplane is released back into service."
"It all comes down to the fact that certain planes are designed to be significantly lighter when landing than when taking off -- in some cases more than 200,000 pounds (90,909.1 kilograms) lighter [source: Boeing]. This may sound backwards; one might think that taking off at a heavy weight would necessarily be harder than landing with that same weight. But landing can put more stress on a plane. When a plane lands heavy, it's very easy to hit the ground too hard and cause damage to the aircraft."