Piper PA-23-250 N318CA accident near Hillsboro, Oregon

Probable cause

A runway overrun due to an insufficient stopping distance due to the downsloping runway during a rejected takeoff. Contributing to the accident was a cabin door that inadvertently opened during the takeoff roll.

NTSB analysis

The flight was to be the private pilot's first multiengine lesson. Both he and the instructor performed an uneventful preflight check and run-up, which included a check of the brakes and the security of the cabin door. During the takeoff roll, the cabin door opened, and the flight instructor called for the pilot to abort the takeoff. The pilot reduced engine power to idle and applied pressure to the brake pedals. The airplane began to decelerate; however, as it approached the end of the runway, brake effectiveness began to dissipate, and the airplane travelled beyond the threshold, coming to rest in a ditch.

The airplane was equipped with foot-operated brakes on the left side only, which was occupied by the pilot undergoing instruction. The remaining runway distance, had it been flat, should have provided for an adequate distance to stop; however, the runway sloped downhill, with its gradient rapidly increasing beyond the threshold. It is likely that this increased downsloping gradient resulted in an increased distance needed to stop the airplane.

Postaccident examination of the braking system revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for WPR13LA154 for the full record.