What happened
On March 30, 2009, at approximately 18:20 UTC, a Cessna 182P, registration PT-INZ, departed from Fazenda Rosa de Maio in Itaituba, Pará, for a flight to Garimpo Bom Jardim. The aircraft was performing a private cargo and personnel transport operation with a pilot and one passenger on board.
Roughly one minute after takeoff, while the pilot was initiating a left turn at 700 feet, the engine suffered a sudden loss of power. The pilot lost control of the aircraft, which descended through trees and came to rest in a flooded area approximately 900 meters from the runway threshold. Both occupants sustained light injuries, though the pilot suffered burns to the chest due to contact with fuel-contaminated water. The aircraft sustained substantial damage.
The investigation
CENIPA investigators examined the engine and propeller to determine the cause of the power loss. While the engine's external components and assembly appeared normal, a detailed inspection of the interior of cylinder number one revealed the presence of foreign material, including soil and organic matter.
Laboratory analysis conducted by the Federal University of Pará (UFPA) confirmed that this material—consisting of quartz, hematite, kaolinite, mica, and plant fragments—was entirely foreign to the engine's internal environment. Investigators ruled out the possibility of this material entering the cylinder during the crash, as the cylinder structure would not allow such access. The investigation concluded that the material had been intentionally inserted through the spark plug holes, specifically the upper plug of cylinder number one.
Additionally, the investigation noted that the aircraft was significantly overweight at takeoff, weighing 1,572 kg, which was 234 kg above its maximum takeoff weight of 1,338 kg. The aircraft was also operating without its two rear seats and was transporting unsecured cargo.
Findings
- The presence of soil and organic matter in cylinder number one caused spark plug fouling and increased the compression ratio, likely leading to pre-ignition and the subsequent loss of engine power.
- The foreign material was intentionally introduced into the engine via the spark plug orifice.
- The aircraft was operating in an overweight condition, exceeding the maximum takeoff weight by 234 kg.
- The aircraft was being operated without the rear seats and with improperly secured cargo.
- The pilot's medical certificate had been expired since October 2008.