Accident Overview
On May 12, 2016, about 1413 Pacific daylight time, a Cessna 208B, registration N1114A, was substantially damaged during a forced landing near Acampo, California. The aircraft was registered to Flanagan Enterprises (Nevada) INC. and operated by the Parachute Center under 14 Code of Federal Regulations Part 91. The commercial pilot sustained minor injuries, and the 17 passengers were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local skydiving flight, which originated about one minute prior to the accident.
Engine Power Loss
The pilot reported that after takeoff from runway 26, a right turn was made and the climb continued for the skydive drop. As the airplane passed 1,000 ft above ground level (agl), the engine lost power. The pilot initiated a turn toward the airport but realized the airport could not be reached and landed in an open field. During the landing roll, the airplane exited the field, crossed a road, impacted a truck, continued into a vineyard, and nosed over.
Examination Findings
Examination by a Federal Aviation Administration inspector revealed substantial damage to the fuselage and left wing. The wreckage was recovered for further examination. On May 17 and 18, 2016, the engine was found partially attached to the fuselage. The fuel pressure line connecting the fuel control unit to the airframe fuel pressure transducer (Pratt & Whitney Canada part number 3033981) was fractured below the fuel control unit fitting swaged seat. The supporting clamp (PWC part number 3006614) was fractured and separated from its mating fuel pressure fuel line (PWC part number 3032010). Additionally, the airframe P3 air line that provides air to the vacuum system exhibited a hole within the tube.
Both the new and old fuel lines and the separated clamp were sent to the National Transportation Safety Board Materials Laboratory. A Senior Materials Engineer examined the components and reported that the fuel line fracture surfaces showed features consistent with crack initiation due to reverse bending fatigue. The metal band of the clamp was fractured near the intersection of the tab and the loop portion, with fracture surfaces consistent with crack initiation at the inward-facing side of the tab due to bending fatigue. The fracture surface exhibited a comparatively flat appearance with curved crack progression marks.
Maintenance History
The operator reported that the fuel line (PWC part number 3033981) was replaced the night before the accident because the original fuel line had fractured. The new fuel line had about 4 hours of operational time since installation. Review of maintenance logbooks showed an entry dated April 11, 2016, for replacement of the fuel line, but no airframe, engine, or HOBBS meter times were listed. The operator stated they used the manufacturer's manual for engine maintenance and that the supporting clamp was attached at the time of the fuel line replacement.