This October 2007 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: Bellanca 7GCBC. Location: Newton, Ga. Injuries: 1 Fatal. Aircraft damage: Substantial.
What reportedly happened: The new private pilot was on a short cross-country flight to build flight time. While in cruise flight, the airplane’s right outboard wing separated at the wing strut attachment point. The airplane descended out of control and hit the ground in a near-vertical nose-down attitude.
Review of the airplane’s maintenance logbook showed that an annual inspection was completed about 10 days and 4.2 flight hours before the accident. The airframe total time was recorded at 8,021.2 hours.
The write-up found in the logbook stated that on the day of the annual inspection, the A&P/IA complied with airworthiness directive (AD) 2000-25-02 R1, by inspecting the wood wing spars in accordance with American Champion Aircraft Corp. (ACAC) Service Letter 406. The mechanic stated that no cracks were detected.
The post-crash inspection of the right wing found several inspection holes, one of which was located at the wing strut attachment point on the underside of the wing. There were also several inspection holes on the upper surface of the wing. However, the location and number of inspection holes were inadequate to allow total compliance with the AD or Service Letter. It was determined that the wing failed because of preexisting compressive damage. Given the size of the area of preexisting damage, investigators determined that had the IA inspected the wing spars at the wing strut attach point he would have seen the preexisting damage.
Probable cause: The failure of the right wing wooden spar due while the airplane was in cruise flight, due to the mechanic’s inadequate annual inspection and his failure to comply with an airworthiness directive.