This December 2008 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: Ercoupe 415-D. Injuries: 2 Fatal. Location: Sebring, Fla. Aircraft damage: Destroyed.
What reportedly happened: The 70-year-old pilot, who held commercial, instructor, multiengine and instrument ratings, had logged 7,126 hours, including 12 in Ercoupes. The airplane was manufactured in 1946. According to maintenance records, its most recent annual inspection was completed on May 9, 2008. At the time of the inspection, the airplane had accumulated 2,588 total hours of operation.
According to a friend of the pilot, who was also a certificated aircraft mechanic, he and the pilot flew together on a local sightseeing flight immediately prior to the accident flight. The mechanic did not note any abnormalities with the performance of either the airplane or the pilot during their flight. Upon returning to the airport, the mechanic disembarked the airplane and another passenger boarded.
Witnesses on the ground told investigators that the Ercoupe was flying low over the passenger’s home. The airplane entered a high-speed dive, pulled up sharply, then rolled steeply to the left. One of the witnesses told investigators that both ailerons were fluttering and it appeared something metallic came off the plane just before both wings separated from the fuselage and the airplane broke up.
Examination of the wreckage revealed that the wing spar failed in an overload at its center. Investigators found a hole not specified in the design of the airplane at the point where the separation of the spar began. The effect of the hole on the pre-accident structural strength of the spar could not be determined. No corrosion or evidence of a fatigue failure was observed in the vicinity of the initial separation.
Probable cause: The pilot’s decision to exceed the design stress limitations of the airplane.
For more information: NTSB.gov