Czech Sportplanes Sro DYNAMIC WT9 N247DY accident near Glendale, Arizona

Probable cause

The pilot did not shut down the engine upon recognizing a brake malfunction. Contributing to the accident was the airplane's brake malfunction for undetermined reasons.

NTSB analysis

According to the pilot, he performed a brake check and used the brakes numerous times while taxiing to the run-up area; however, as he approached the run-up area, the brakes failed, and the airplane continued to roll forward. He decided to steer the airplane off the taxiway surface and not risk an excursion onto the active runway. The airplane veered off the paved surface onto unprepared desert terrain, and the airplane continued to accelerate. The pilot attempted to shut down the engine with the ignition switch, but was unable to. He said that normal engine shut down is accomplished using two magneto switches on the instrument panel and not the ignition switch. The airplane then struck a boundary fence.

Postaccident examination revealed that the left wheel brake assembly was damaged by impact forces consistent with the airplane’s collision with the fence. The examination of the brake system for fluid leaks and functionality did not disclose any evidence of a preexisting mechanical malfunction that would have precluded normal operation. It is likely that, if the pilot had shut down the engine before the airplane departed the taxiway surface, he would have been able to stop in time to avoid colliding with the airport boundary fence.

Text from the NTSB. Open the NTSB docket for WPR12LA074 for the full record.