Aircraft Braking System Test: High-Speed Aborted Takeoff

Boeing has successfully completed a critical rejected takeoff (RTO) test for the 777-9, marking a significant milestone in the certification process for the largest variant of the 777X family.

The test, conducted in early 2026 at a dedicated high-speed runway facility at Edwards Air Force Base, demonstrated the aircraft’s ability to stop under extreme conditions. The procedure simulated a high-speed abort scenario at maximum takeoff weight.

During the evaluation, the 777-9 reached a maximum takeoff weight of 775,000 lbs (351,550 kg) with full fuel loads. The aircraft accelerated to just below rotation speed before pilots initiated maximum braking and deployed spoilers.

According to reports, the aircraft’s brakes reached temperatures of approximately 2,500°F (around 1,370°C) during the stop. The test was specifically designed to dissipate kinetic energy equivalent to several hundred megajoules entirely through the braking system, without the use of thrust reversers.

Certification and Regulatory Compliance

The RTO test is a mandatory certification requirement to ensure the aircraft can safely stop at decision speed, known as V1. V1 is the critical point at which a takeoff must either continue or be safely rejected to avoid overshooting the runway.

This milestone demonstrates compliance with strict certification standards established by regulators, including the Federal Aviation Administration (FAA). The test provides verified data on how the aircraft performs during rare but critical emergency scenarios.

Technical Specifications and Braking Systems

The Boeing 777-9 is designed to carry up to 426 passengers in a typical two-class configuration. To handle the immense energy generated during a maximum-weight abort, the aircraft utilizes advanced carbon brake discs.

These carbon components are engineered to be more heat-resistant and lighter than traditional steel brakes, allowing them to endure extreme temperatures without structural failure or loss of stopping performance.

The test also evaluated the limits of the aircraft’s tires. The 777-9 is equipped with fuse plugs designed to release pressure safely when exposed to extreme heat, a process that often results in tire deflation during such rigorous testing.