What happened
On March 16, 2022, an Embraer EMB 202A Ipanema, registered as PT-UTF, was performing agricultural spraying operations at Fazenda Vitória in Feliz Natal, Mato Grosso. The aircraft, operated by Agrifor Aviação Agrícola, was conducting a series of spray passes over a corn plantation.
During the sixth pass, the pilot reported feeling abnormal vibrations and noises during reversal turns. Although the pilot continued the mission, during the fifth pass of the seventh sortie, a loud bang was heard while performing a left-hand repositioning turn. This was immediately followed by a loss of engine power and altitude. The pilot executed emergency procedures, including jettisoning the load, and performed a forced landing in the cornfield. The aircraft sustained substantial damage, though the pilot escaped with minor injuries.
The investigation
CENIPA investigators examined the engine, the aircraft's maintenance records, and the flight planning data. The investigation focused on the engine's performance and the mechanical state of the Lycoming IO-540-K1J5 powerplant.
Technical analysis of the fuel injection system revealed that the fuel injection servo was delivering flow rates exceeding the maximum permitted limits when operating with a rich mixture. Furthermore, upon removing the cylinders, investigators found significant carbon buildup on the piston heads, sediment accumulation, and evidence of wear and corrosion on the tappets and camshaft.
Additionally, the investigation noted that the aircraft had departed with a weight exceeding its maximum takeoff weight (MTOW) for the restricted category. It was also observed that the pilot did not strictly follow the emergency landing checklist, specifically failing to shut off the mixture control, the fuel selector valve, and the alternator. Investigators also noted that evidence was compromised because the ignition cables for cylinders 4 and 6 showed signs of being forcibly removed after the accident, and the stall warning circuit breaker was found disarmed.
Findings
- Engine malfunction due to excessive fuel flow from the injection servo.
- Internal engine wear, including carbonization and camshaft corrosion, which likely led to a loss of compression.
- The aircraft departed above its maximum takeoff weight.
- Incomplete execution of emergency shutdown procedures following the engine failure.
- Alteration of engine components (ignition cables) after the occurrence, preventing full analysis of the ignition system.