Whenever new passenger planes are built, they must go through a number of tests designed to determine whether the plane performs well under extreme circumstances, and to allow designers and engineers to fine-tune aircraft designs before they go into production.
In this video, you can see a rejected takeoff (RTO) test for the Airbus A340. The test is designed to see how the brakes perform when they are forced to stop a plane at its maximum designed weight and highest runway speed possible before the crew is committed to taking off. At the end of the test, circumstances get a little out of hand, and the pilots start to get exasperated.
The second video is an excellent discussion about many other tests performed during aircraft testing.
This video explores what happens when the runway is really wet and the spray from the wheels is ingested by the engines.
Image Credit: Airbus Aircraft