What happened
The pilot reported experiencing an unexpected loss of engine power while the aircraft was in cruise flight. Unable to maintain altitude or reach a suitable airport, the pilot initiated an off-airport emergency landing. During the approach and touchdown, the aircraft struck a soft spot on the ground. The impact caused the nose gear to collapse, resulting in the aircraft nosing over.
The investigation
Post-accident examination of the aircraft revealed significant issues with the fuel system integrity. Investigators found contaminants within the fuel tanks, which were traced back to tank caps that did not seal properly. A visual inspection of the fuel cell bladders disclosed permanent ridges measuring one-half to three-quarters of an inch throughout the bottom surface of both the left and right bladders.
Findings
The primary factors contributing to this accident included fuel exhaustion caused by contamination entering the system due to improperly sealed tank caps. The resulting power loss necessitated an emergency landing, where the aircraft encountered a soft spot on the ground, leading to structural damage including the nose-over.
Safety message
Proper maintenance of fuel system components, particularly tank seals and caps, is critical to preventing contamination. Pilots should ensure that all fuel access points are securely sealed to protect against external contaminants that can impair engine performance.