What happened
On January 23, 2012, an EMB-201A, registration PT-UDH, was performing agricultural spraying operations in the region of Tasso Fragoso, Maranhão. After completing two spraying missions early in the morning, the pilot prepared the aircraft for a flight to Fazenda Sapucaí, located approximately 30 km away. The aircraft took off at approximately 09:30 UTC with the pilot and one assistant on board.
During the flight, the aircraft experienced a critical mechanical failure. An engine cylinder (number 2) detached from the Lycoming engine and was found approximately 80 and meters upstream from the impact site. Following the loss of the component, the aircraft crashed into a soybean plantation at Fazenda Piraíba. The impact occurred at an angle of approximately 25 degrees with the aircraft in an inverted position. The aircraft was completely destroyed by the impact and subsequent fire, and both occupants sustained fatal injuries.
The investigation
CENIPA's investigation focused on the mechanical failure and the operational circumstances leading to the crash. Investigators located the missing cylinder along the flight path, confirming a loss of component in flight. The investigation examined the aircraft's maintenance history, noting that the engine had recently undergone a top overhaul and propeller dynamic balancing in December 2011.
The investigation also reviewed the pilot's workload and decision-making process. It was noted that the aircraft was being operated in a manner that deviated from its type specifications. Furthermore, investigators looked into the meteorological conditions, which included low-level clouds and potential fog in the area, which may have forced the pilot to fly at a lower altitude.
Findings
- The loss of an engine cylinder in flight was the primary mechanical event.
- The pilot made a critical error in the decision-making process by carrying an unauthorized passenger (an assistant) in a single-seat aircraft, which likely hindered the ability to maintain effective control during the engine failure.
- The presence of an extra person in the cockpit may have physically obstructed the pilot's ability to apply full control inputs.
- High workload and physical/mental demands associated with agricultural spraying operations may have negatively impacted the pilot's perception of risk.
- The pilot's decision to manage the engine's break-in period personally to expedite operations may have influenced the quality of the engine's condition.