Bellanca 7KCAB N11858 accident near Corona, California

Probable cause

The total loss of engine power due to oil exhaustion as a result of a broken oil line.

NTSB analysis

During an instructional flight, the engine experienced a total loss of power. The flight instructor took over the controls and made a forced landing on a golf course. During the landing roll, the airplane nosed over into a sand trap, damaging the tail and fuselage. Postaccident examination of the airplane revealed a large amount of oil covering the underside of the fuselage. Examination of the engine revealed that the oil pressure line had failed just aft of the “B” nut that connected the line to the engine fitting resulting in the loss of all engine oil. Chaff marks were noted on the metal sleeve between the “B” nut and the flexible portion of the line. These chaff marks were the result of rubbing against the bottom side of the engine shock mount assembly. When the undamaged end of the oil line was installed on the engine fitting, it was noted that there was visible clearance between the line and the engine shock mount. It is likely that, with the engine operating, vibration resulted in contact between the line and the mount.

Text from the NTSB. Open the NTSB docket for WPR11LA070 for the full record.