The newest variation of the well know 747 airliner underwent some worst case scenario testing to ensure that they are safe for their size. weighing almost 1,000,000 pounds with a full load, or about 500 tons, this super flyer underwent a crash course in emergency takeoff abortion. The test planes brakes were replaced with ones that were 100% worn out, the plane was loaded to its maximum flying weight capacity, and the test pilot was not allowed to use the planes thrust reverses. the test began as a normal takeoff and when the plane reached between 200 and 300 miles per hour, the pilot slammed on the breaks. The massive machine slowed down and reached a full stop much sooner than Boeing had hoped but the test was not over because stopping the plane is only half of the test. The tremendous heat produced in the breaks during the emergency stop can damage a plane even after it appears to be safe. The fire department was on the scene within a few seconds but since it was a worst case scenario, they were not allowed to intervene for 5 minutes which was the maximum estimated response time. The tires automatically de-pressurized to prevent an explosion. At the five minute mark the firefighters cooled down the landing gear. The wheels landing gear will have to be replaced on the massive plane but everything else on the plane is unscratched and in perfect working order.