Incident Overview
On April 20, 2013, at approximately 1027 Pacific daylight time, a Boeing A75N1 airplane, registration N985SS, sustained substantial damage during a forced landing near Santa Rosa, California. The aircraft was registered to and operated by the pilot under Title 14 Code of Federal Regulations Part 91. The commercial pilot, who was the sole occupant, was not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the local personal flight, which originated from Petaluma, California, about 1000.
Sequence of Events
The pilot reported that while joining up in formation flight with a second airplane, he reduced power to slow down. When he subsequently increased the throttle, he noticed no response from the engine. The engine was still running, but movement of the throttle and application of the electric fuel boost pump did not alter the engine's power setting. The pilot initiated a forced landing to a vineyard. During the landing roll, the airplane nosed over.
Damage and Examination
Examination by a Federal Aviation Administration (FAA) inspector revealed structural damage to the upper left wing. The recovered engine was examined; the throttle linkage remained attached and could be moved from stop to stop by hand. The main fuel system screen contained a fuzzy, spongy material along with other debris. The throttle body fuel screen contained many small particles. Fuel was removed from both the main and lower fuel tanks, and debris was found in the lower fuel tank fuel sample. The source of the debris was undetermined.
Findings
The exact cause of the engine power loss could not be determined from the examination. The debris found in the fuel system may have contributed to the issue, but its origin remained unknown.