Mechanical & Engine Failure · NTSB CHI08LA166
HELTON LARK 95 — West Carrollton, OH
| Date | June 17, 2008 |
| Location | West Carrollton, OH |
| Aircraft | HELTON LARK 95 |
| Purpose of flight | Ferry |
| Conditions | Day · Visual Meteorological Cond |
| Phase / occurrence | Emergency descent Collision with terr/obj (non-CFIT) |
| Pilot age | 37 |
| Pilot total time | 10,328 hrs · High time |
| Time in type | Unknown |
| Fatalities | 1, 1 serious |
Probable cause
NTSB findings
- Aircraft-Aircraft power plant-Ignition system-Spark plugs/igniters-Incorrect service/maintenance - C
- Environmental issues-Physical environment-Object/animal/substance-Pole-Contributed to outcome - F
- Environmental issues-Physical environment-Object/animal/substance-Tree(s)-Contributed to outcome - F
What happened
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.