Overview
A pilot reported experiencing a propeller runaway while leveling off from a climb. During the event, the pilot observed oil streaming from the left engine. He was unable to feather the propeller. Unable to maintain altitude with a windmilling propeller, he executed a gear-up emergency landing in the desert.
Investigation Findings
After the landing, teardowns of the engine were performed. However, investigators discovered that the evidence had been tampered with. As a result, the origin of the malfunction could not be determined.
Regulatory Outcome
Following the incident, the operator voluntarily surrendered its Part 121 certificate.