Cessna 150F N8637S accident near Midland, Texas

Probable cause

The improper installation of the generator by unknown personnel, which resulted in a loss of oil and subsequent engine failure.

NTSB analysis

The student pilot stated that the preflight, engine run-up, and takeoff were normal with no anomalies noted. About 15 minutes into the solo cross-country flight, the engine lost total power, and he performed a forced landing to a tree-covered area. During the forced landing, the airplane impacted a power line and trees. Examination of the airplane revealed oil residue on the back of the engine, lower engine cowling, and the right main landing gear strut. The top mounting nut on the generator was missing, and the two lower mounting nuts were loose. Evidence of oil leakage past the generator mounting gasket was identified after removal of the generator from the engine. A hole in the engine crankcase was noted above the No. 1 cylinder. In addition, examination of the engine run-up and taxiway area, consistent with where the student pilot completed his engine run before the flight, showed a large oil stain and residual oil. The aircraft records did not reveal any recent maintenance to the generator or engine accessories; however, it is likely that when the generator was installed, the nuts were not properly tightened, leading them to back off over time, which led to the loss of oil.

Text from the NTSB. Open the NTSB docket for CEN18LA040 for the full record.