What happened
On April 8, 2009, a Cessna 310Q, registration PT-IOH, operated by W&J Táxi Aéreo, was performing a navigation circuit involving a touch-and-go at Alenquer Airport before returning to Santarém (SBSN). During the landing roll at SBSN, after the aircraft had decelerated to taxi speed, the right wing began to descend slowly. This movement continued until the right propeller blades struck the ground. Following the impact, the aircraft veered off the runway into the adjacent grass area. The two crew members on board were uninjured, though the aircraft sustained light damage.
The investigation
CENIPA investigators examined the aircraft's landing gear assembly and identified a fracture in the right main gear lock adjustment end fitting (End Fitting Assy, PN 0841111-1). Laboratory analysis by the Institute of Aeronautics and Space (IAE) determined that the fracture was caused by an overload, likely resulting from an impact. While there were no previous records of hard landings, the investigators noted that the damage to the component was consistent with excessive loading.
Furthermore, the investigation revealed significant discrepancies in the aircraft's maintenance program. The operator's continuous airworthiness program had established a maintenance interval of 10,000 flight hours for specific landing gear inspections. However, the manufacturer's Supplemental Inspection Document (SID) required these inspections to be performed based on 10,000 landings or 20 years from the date of manufacture, with subsequent repetitions every 5,000 landings or 10 years. The investigation found that the required supplemental inspections had not been performed since the aircraft's manufacture in 1974.
Findings
- The fracture of the right main gear end fitting was caused by an overload/impact.
- The aircraft's maintenance management lacked effective oversight, as the technical maintenance control was managed by a single employee serving both the operator and the maintenance provider.
- The maintenance program for PT-IOH was in disagreement with the manufacturer's instructions, specifically regarding the frequency of supplemental landing gear inspections.
- The failure to perform the required supplemental inspections prevented the timely detection of potential fatigue or wear in the landing gear structure.