Feature Story

787-9 brakes withstand extremes

Getting a chance to run tests on a brand new airplane is one of the highlights of working in Boeing Test & Evaluation. Case in point, the new Boeing 787-9 Dreamliner. As with all new airplanes, the BT&E team must demonstrate that, even when fully loaded, the plane can stop a takeoff on short notice. “To certify the airplane we make sure that airplane can stop on the runway at its highest take off weight and its maximum speed,” said Boeing Test & Evaluation flight test director, Miguel Marmol.

In addition to the speed and weight factors, test personnel install the airplane with brakes that are 99% worn. “We grind the brakes down to the thinnest they could ever be… we go to extreme lengths to make sure the test is the absolute possible worst-case scenario,” said Marmol.

“We grind the brakes down to the thinnest they could ever be… we go to extreme lengths to make sure the test is the absolute possible worst-case scenario.”

After months of preparation from test engineers, pilots, emergency crews, and airport personnel, to name just a few, the test begins. The airplane is accelerated to approximately 188 knots groundspeed, and then pilots slam on the brakes. After a complete and safe stop, the BT&E test team monitors the heat generated from the force placed on the brakes. It’s a force so great, a dull orange glow of heat can be seen coming from the brakes and wheels. “The tires themselves deflate per design. They have devices called fuse plugs within the wheels themselves that melt under high temperature and then, in a very controlled fashion, release the pressure of the air of the nitrogen in the tire so they don't blow treads,” said Boeing Test & Evaluation project pilot, Heather Ross.

The 787-9 made it through every phase of this testing exactly as expected. Bringing the 787-9 one step closer the flying public.

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