This April 2009 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Cessna 152. Injuries: 2 Minor. Location: Glendale, Ariz. Aircraft damage: Substantial.
What reportedly happened: The CFI and student were returning to the airport when the airplane’s engine began running rough. The roughness became increasingly worse, and finally the engine lost power. The CFI was unable to restart the engine, and he initiated a forced landing onto a nearby grassy field. During the landing roll, the airplane hit a chain link fence, resulting in structural damage to the right wing.
During the post-accident examination, several unsuccessful attempts were made to start and run the engine but it would not start. The magnetos were removed and tested, and neither produced spark. Disassembly of the left magneto revealed the failure of the secondary coil. Disassembly of the right magneto revealed that the point gap was set incorrectly and that the lead connector from the magneto’s coil to the points was loose. Review of maintenance records revealed that the magnetos were removed three tachometer hours prior to the accident and new points, capacitors, and gaskets were installed and the magnetos were reinstalled on the engine.
Probable cause: A loss of engine power due to the failure of both magnetos resulting from an improper maintenance repair by maintenance personnel.
For more information: NTSB.gov