What happened
On May 26, 1994, an EMB 711C (registration PT-NIM) departed from Bacacheri Airport (SBBI) bound for Três Barras (SSTB). Although the pilot filed a visual flight plan (VFR) requesting flight level 085, the aircraft encountered cloud cover shortly after takeoff. Witnesses observed the aircraft emerging from a cloud layer in an uncontrolled state before impacting the ground in the Cidade Industrial area of Curittiba, Paraná. The impact occurred in an inverted attitude, followed by a post-crash fire. The pilot sustained fatal injuries, and the aircraft was a total loss.
The investigation
The investigation focused on the aircraft's structural integrity and the pilot's decision-making. Technical analysis by the CTA of the engine and propeller group confirmed the powerplant was fully operational at the time of impact. However, examination of the stabilizer support components—specifically the threaded pin and fittings—revealed that fractures had occurred due to overload. A piece of the left wing was found 1,200 meters from the wreckage, with evidence of rivet failure and structural tearing.
Investigators also examined recent maintenance records, noting that a recent repair to address lateral play in the stabilizer involved replacing washers with thicker ones without a formal service order. Furthermore, the investigation noted that the pilot, while holding an IFR rating, had very limited experience in instrument conditions and was operating an aircraft that was not certified for IFR operations.
Findings
- Spatial Disorientation and Improper Command: The pilot likely experienced spatial disorientation after entering clouds, leading to violent control inputs that exceeded the aircraft's structural limits.
- Structural Failure: The extreme aerodynamic loads during recovery maneuvers caused the failure of the stabilizer support and the separation of part of the left wing.
- Human Factors: The pilot's personality traits, characterized by impulsivity and overconfidence, contributed to the decision to proceed into IMC (Instrument Meteorological Conditions) despite being in a non-IFR certified aircraft.
- Operational Deviations: The pilot failed to adhere to the filed VFR flight plan and did not return to the departure airport when faced with deteriorating weather.
- Maintenance Discrepancies: While the exact cause of the structural failure could not be definitively linked to the recent washer replacement, the investigation noted irregularities in maintenance logging and unrecorded minor repairs.