This August 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: RV-6. Injuries: 1 Fatal. Location: Caldwell, Idaho. Aircraft damage: Destroyed.
What reportedly happened: According to a family member, the airplane had sat on the ramp for about a year without having been flown. About a week before the accident, the pilot flew the plane once around the traffic pattern. On the day of the accident, the pilot removed and sandblasted the spark plugs, checked the cylinders for compression, and removed and cleaned the air filter. Some sort of foreign matter was found in the filter.
A witness reported observing the airplane take off. As the airplane went by him at 100 to 200 feet above ground level, it was making a popping noise. The airplane made a quick left turn to a left downwind leg, and as the airplane continued on the downwind, the nose pitched up, but the airplane did not appear to be climbing. As the airplane came abeam the numbers, it made a steep left turn, followed by the nose dropping before it dove into the ground and erupted in flames. The airplane was destroyed by fire.
A post-accident examination of the engine revealed no anomalies with the cylinders and valve train. All spark plugs were found to have excessive gaps, and all but one failed a bench check when exposed to pressure greater than 80 PSI. No aircraft or engine logbooks were located during the investigation.
Probable cause: The pilot’s failure to maintain adequate airspeed that led to a stall/spin while maneuvering in the traffic pattern.
For more information: NTSB.gov NTSB Identification: WPR09LA378.