LARK 95 N86657 accident near West Carrollton, Ohio

Probable cause

The improper installation of spark plugs during the annual inspection which resulted in a loss of engine power shortly after takeoff. Contributing to the accident was the lack of suitable terrain during the forced landing.

NTSB analysis

Shortly after takeoff, the airplane entered a descending left turn. The airplane contacted a utility pole, a light pole, and a tree prior to coming to rest. A witness stated the airplane sounded fine on takeoff, but the engine began to lose power shortly thereafter. Post accident inspection of the airplane and engine revealed the number four cylinder sustained impact damage in the area of the top spark plug. The top spark plug on this cylinder was found separated from the engine. The top spark plugs on the remaining cylinders were loose. The accident occurred on the first flight following an annual inspection. The mechanic who signed off the inspection stated he checked the torque on the spark plugs after they were installed. The airplane was topped off with fuel prior to the flight. The pilot's logbook did not show any entries indicating that he had ever flown a Lark 95 prior to the accident flight and the passenger stated this was the pilot's first flight in the airplane.

Text from the NTSB. Open the NTSB docket for CHI08LA166 for the full record.