Heat is on: 777-9 performs critical test as brakes reach 2,500 degrees

The 777-9 team simulated one of the most challenging situations that the airplane could face during maximum brake energy testing at Edwards Air Force Base in California.

• Following certification protocol, the team loaded the airplane to its highest takeoff weight, and pilots accelerated to approximately 190 knots before aborting the takeoff and applying full braking.
• “Maximum brake energy is one of the most highly choreographed tests that we do,” said Madison Strauss, 777-9 test director.

Intense conditions: “We don’t use thrust reversers, so the brakes provide 100% of the stopping power of the airplane,” said Matt England, 777-9 flight test engineer. “We do the condition on brakes that are intentionally machined down to 100% worn so it’s a worst-case simulation.”

• “It's just conditions that you'll never see in service,” added Brianna Hitchcock, 777-9 flight test engineer. “But regulations require it, and we test it.”

Withstanding the heat: The brakes being tested generated over a billion foot-pounds of torque to stop the airplane, causing them to glow with extreme heat — exceeding 2,500 degrees Fahrenheit (1,371 degrees Celsius).

• “We’re optimizing the conditions to make sure we put the most energy we possibly can into those brakes,” said Capt. Heather Ross, 777-9 project pilot.

The wheels were so hot that the fuse plugs melted – as designed, safely releasing air from the tires.

Prioritizing safety: As part of the test, emergency crews were on standby but waited five minutes before engaging with the airplane to simulate a realistic emergency response.

After the waiting period passed and the demonstration was complete, crews sprayed water on the wheels and brakes to cool them.

• “The conditions were executed flawlessly,” said Ross. “I’m incredibly proud of the airplane and the team.”

Why it matters: The 777-9 is completing rigorous Boeing and U.S. Federal Aviation Administration certification testing to demonstrate the airplane’s safety, reliability and performance.

• “We’ve had a lot of experience with this airplane – there really isn’t a system that we haven’t tested,” Ross said. “Everybody is working together to show we meet the requirements.”

The bottom line: “The team demonstrated impressive dedication and resolve to complete these critical tests,” said Terry Beezhold, 777-9 vice president and general manager. “A big thanks to them and everyone who is working hard get this airplane certified and delivered to our customers.”

By Jen Cram