What happened
On May 11, 2022, a Cessna 208, registration PT-OQR, operated by Skydive4fun Serviço Aéreo Especializado Ltda., was performing a local parachute drop flight from the Boituva Aerodrome in São Paulo. During the initial climbout, the aircraft experienced a loss of engine power. The pilot attempted an emergency landing in a nearby rural area.
During the landing sequence, the aircraft struck an embankment and a fence before eventually overturning. The impact caused substantial damage to the airframe, including the detachment of the nose landing gear, damage to the wings and empennage, and the separation of the engine mount. The accident resulted in two fatalities among the passengers. Additionally, the pilot and four passengers sustained serious injuries, four passengers suffered minor injuries, and five passengers remained uninjured.
The investigation
CENIPA's investigation examined the mechanical state of the Pratt & Whitney PT6-42A engine and the structural integrity of the passenger restraints. Investigators noted that flames were visible from the left engine exhaust during the emergency descent and that the Interstage Turbine Temperature (ITT) was operating near its physical limit.
Regarding the cabin, the investigation found that the seat belt attachment points utilized a single-pin design and showed signs of corrosion. During the impact, the force caused many seat belts to detach as the floor attachment brackets sheared. It was also noted that the aircraft's passenger seating configuration had undergone modifications that were not fully documented in the aircraft records.
Findings
- The improper use of the Emergency Power Lever (EPL) during flight training and routine operations likely contributed to engine degradation.
- Ineffective maintenance of the seat belt attachment brackets, which were found to be corroded, contributed to the severity of the injuries sustained by the passengers.
- The use of single-pin seat belt anchors provided insufficient restraint during the high-dynamic loads of the impact.
- There was a lack of managerial oversight regarding the operational risks associated with using the EPL in violation of manufacturer specifications.