What happened
During a ferry flight intended to transport the aircraft to another airport for an annual inspection, the aircraft's left wing separated in flight while maneuvering. The aircraft subsequently impacted terrain. According to a witness, a post-impact ground fire engulfed the airplane approximately 10 to 15 seconds after the impact occurred.
The pilot had been in the process of purchasing the aircraft, which had reportedly not flown for approximately four years and had not had its engine started for about six months. The pilot was aware that the aircraft lacked a current annual inspection. On the day of the accident, the pilot departed toward his home before the structural failure occurred. A witness observed a portion of the wing breaking away from the airplane during the flight.
The investigation
An examination of the wreckage at the scene revealed that the forward strut of the left wing had separated approximately eight inches above its fork bolt. Investigators found that the interior of this strut was corroded. No other anomalies were detected on the aircraft prior to the impact. Additionally, investigators noted that there was no entry in the airplane logbook for the special flight permit required to ferry the aircraft for its annual inspection.
Findings
- The left wing's forward strut failed due to internal corrosion.
- Airworthiness Directive 99-01-05, which required repetitive 12-calendar-month inspections of the wing lift struts to prevent in-flight separation caused by corrosion or cracked forks, had last been performed approximately four years prior.