Aero Commander 690 N9175N accident near Scottsdale, Arizona

Probable cause

The pilot’s loss of directional control during the landing roll, which resulted in the runway excursion onto the rock-covered runway safety area.

NTSB analysis

The pilot reported that, during the landing roll, he commanded reverse thrust and lightly applied brake pressure. While he was reaching for the condition levers to bring the propellers back to low rpm, the airplane suddenly veered to the right. The pilot applied left braking action and adjusted the engines to low rpm, but the airplane continued to veer toward the right side of the runway and a runway sign. The pilot reported that he could have either gotten more aggressive with the corrective actions and hope to avoid striking the sign, or allow the airplane to exit the runway onto what he thought was a hard, smooth surface. The pilot chose to exit the runway surface, and the airplane entered the runway safety area, which had a rock layer that consisted of river rock. The landing gear sunk deep into the rocks, which quickly slowed the airplane to a stop. Several rocks penetrated the fuselage, which resulted in substantial damage.

A postaccident examination of the steering and brake system revealed no evidence of a mechanical failure or malfunction that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for WPR17LA030 for the full record.