Accident Description
A commercial pilot was repositioning a float-equipped airplane to its mooring site after the aircraft had undergone a 100-hour inspection. Approximately two minutes after departure, the pilot reported a loss of engine power. The pilot selected a small pond as a forced landing site. After touchdown on the pond, the airplane collided with the shoreline and nosed over. The airplane sustained substantial damage to the left wing, right wing lift strut, empennage, and fuselage.
Postaccident Investigation
A postaccident inspection of the airplane revealed that the fuel selector handle had been inadvertently reinstalled incorrectly during the recent 100-hour inspection. When the fuel tank selector handle was placed in the "Both" position, it actually turned the fuel supply off. Further investigation revealed slight wear to the keyed cog of the fuel selector valve handle (female receptacle), as well as slight wear to the fuel selector valve connection point (male receptacle). The combined wear patterns of both the fuel selector valve handle and the fuel selector valve connection point allowed the installation of the fuel selector handle 180 degrees from its correct position.
Findings
When a new fuel selector valve handle was fitted onto the valve connection point, it could only be installed in the correct position and not 180 degrees from the correct installation. The accident was attributed to the incorrect reinstallation of the fuel selector handle during maintenance, which was facilitated by wear on the selector valve components.