Piper PA-28-235 N49DS accident near Rock Springs, Wyoming

Probable cause

The pilot's inadvertent movement of the fuel selector valve beyond its tank detent, which resulted in a total loss of engine power due to fuel starvation. Contributing to the accident was the failure of the fuel selector interlock mechanism.

NTSB analysis

After an uneventful cross-country flight, the pilot initiated the landing descent by reducing engine power. As the airplane approached the airport's base leg, he performed the landing checklist, which included switching the fuel selector valve to the left tip tank. As the airplane turned from the base to final leg, it descended too low, and he applied full engine power. The engine did not respond, and a few seconds later lost all power. With limited altitude to complete a thorough emergency check, he performed a forced landing into rough terrain. During the landing sequence, the airplane struck a fence and berm, sustaining substantial damage to both wings.

Following the accident, the pilot expressed concern that he may have inadvertently starved the engine of fuel during the approach, by turning the fuel selector valve beyond its left tip tank travel limit, and to the OFF position. The airplane's fuel selector lever was fitted with an interlock mechanism, which was designed to prevent the pilot from inadvertently shutting off the fuel in this manner. Examination revealed that the mechanism had shifted, such that the fuel selector lever could be moved to a position in-between the left tip tank, and OFF detent without engaging the interlock, therefore possibly resulting in an interruption of fuel flow to the engine.

Data extracted from the engine monitor, as well as the minimal quantities of fuel recovered from the fuel system components within the engine compartment, were consistent with a fuel starvation event.

A postaccident examination of the engine and successful engine run revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for WPR13LA094 for the full record.