What happened
On January 8, 2016, an Embraer EMB-202A, registration PT-VVU, was performing agricultural spraying operations near Igarapava, São Paulo. The aircraft, operated by Agrosema Aero Agrícola Ltda, had completed three successful spraying missions before commencing its fourth flight of the day. During this final mission, the pilot reported hearing abnormal noises from the engine area on three separate occasions. Although the pilot checked the engine instruments and found them to be within normal operating ranges, the engine eventually lost power and ceased functioning entirely during a return maneuver.
Unable to return to the departure runway due to insufficient altitude, the pilot performed an emergency landing in a wooded, swampy area. The impact was severe enough that the engine separated from the airframe, coming to rest approximately eight meters from the fuselage. The pilot sustained minor injuries, while the aircraft suffered substantial damage.
The investigation
CENIPA investigators examined the engine and maintenance records to determine the cause of the power loss. Technical testing conducted by the Institute of Aeronautics and Space (IAE) revealed that the left magneto was inoperative, which prevented adequate electrical supply to the spark plugs. This failure likely led to an accumulation of unburned fuel in the combustion chamber, causing the engine to stall.
Furthermore, the investigation uncovered significant discrepancies in the aircraft's maintenance documentation. The serial number of the failed left magneto did not match the number recorded in the aircraft's logs. Additionally, investigators found that maintenance inspections for the engine were not being performed at the intervals required by the manufacturer's manual. The investigation also noted that the pilot had not performed a flight in 232 days, meaning they did not meet the recent experience requirements stipulated by Brazilian civil aviation regulations (RBAC 61).
Findings
- The inoperative left magneto caused irregular fuel combustion and subsequent engine failure.
- Inadequate pilot judgment contributed to the accident, as the pilot continued the operation despite hearing repeated abnormal noises without investigating the source.
- Management oversight by the operator resulted in improper maintenance tracking, including the use of undocumented components and failure to adhere to inspection intervals.
- The pilot failed to meet the regulatory requirements for recent flight experience.