What happened
On March 18, 2005, a Piper PA-25-260, registration PT-DPF, was performing agricultural spraying operations over sugarcane fields for Usina Bonfim in Santa Ernestina, São Paulo. During the return leg of the sixth spraying mission of the day, the aircraft suffered a sudden engine failure.
The pilot attempted an emergency landing in a plowed field approximately two nautical miles from the base of operations. The aircraft struck the ground five times before eventually flipping onto its back after traveling 93 meters. The pilot sustained severe injuries, including a suspected cervical fracture. Although rescued by a highway emergency team, the pilot passed away four days later due to spinal cord injury.
The investigation
CENIPA investigators conducted a thorough examination of the engine and the aircraft's maintenance history. Upon disassembly of the engine, investigators discovered that the camshaft had fractured, effectively severing the component and causing the immediate loss of power. The investigation also revealed that the aircraft's maintenance records, including the engine and propeller logs and the aircraft logbook, were outdated.
Furthermore, investigators found evidence of unauthorized maintenance performed at unapproved locations, such as the installation of an automotive voltage regulator and the deactivation of the fuel cutoff valve. There was also a lack of traceability for the failed camshaft, as no valid documentation could be produced to verify its origin or history. Additionally, the investigation noted that the pilot was not wearing a helmet and likely was not wearing safety harnesses, which may have contributed to the severity of the spinal injuries.
Findings
- The primary cause of the engine failure was the fracture of the camshaft.
- Inadequate maintenance supervision led to the use of untraceable components and unrecorded maintenance services.
- Operational deficiencies were noted, including the pilot's failure to use proper safety equipment (helmet and harnesses) and the failure to use flaps during the emergency approach, which resulted in excessive landing energy.
- The operator failed to maintain reliable documentation regarding aircraft components and maintenance history.