What happened
On February 24, 1990, an EMB 711-C aircraft, registration PT-NJH, operated by Aeroclube de São Paulo, crashed in the Bairro do Chá region of Salesópolis, São Paulo. The flight originated from Campo de Marte with two occupants, traveling toward Ubatuba. After dropping off a passenger at the destination, the pilot began the return leg.
Witnesses reported seeing the aircraft flying at a low altitude and deviating from its intended route, traveling East-to-West instead of the planned West-to-East. During the flight, the engine began to fail and emitted smoke. The aircraft was last seen over a valley between hills with the engine apparently shut down, shortly before impacting the top of a hill. The pilot sustained fatal injuries following the impact. The aircraft suffered severe damage, including the loss of the engine, left aileron, and right flap.
The investigation
CENIPA investigators examined the wreckage and the engine components. Technical analysis by the CTA (Centro Técnico Aeroespacial) confirmed that the number two piston had fractured due to a fatigue crack. This fracture subsequently caused the failure of the number two cylinder. The investigation also noted that the aircraft's landing gear was retracted, the flaps were set to 20 degrees, and the fuel and engine controls were closed, suggesting the pilot attempted an emergency landing.
Investigators also looked into the possibility of pilot disorientation, noting that the aircraft was off-course and the windshield was obscured by oil spray from the engine failure, which may have hindered navigation. While the engine had been well-maintained, the investigation explored whether improper mixture settings or maintenance errors contributed to the overheating that facilitated the fatigue crack.
Findings
- The primary cause of the engine failure was the rupture of the number two piston caused by a fatigue crack.
- The fatigue process was accelerated by engine overheating and potential pressure spikes from detonation.
- The pilot attempted an emergency landing procedure prior to impact.
- The aircraft was operating outside of its planned flight path.
- The pilot's vision may have been compromised by oil leaking onto the windshield during the engine failure.