What happened
On January 5, 2000, a Cessna C-172M, registration PT-KLB, departed from an unregistered dirt airstrip near the Best West Pantanal Mato Grosso Hotel in Poconé, Mato Grosso. The aircraft was performing a private air taxi service, transporting the pilot and five passengers toward Fazenda Sararé.
During the takeoff roll, witnesses reported hearing abnormal noises coming from the engine. Shortly after leaving the ground, the aircraft failed to gain sufficient altitude and entered a 18/0° left-hand turn. The aircraft subsequently struck the Pixaim River at a 45-degree lateral tilt. The impact caused the aircraft to sink rapidly. Of the six people on board, the pilot and three passengers were killed, while the remaining two passengers sustained minor injuries.
The investigation
CENIPA's investigation revealed significant discrepancies regarding the aircraft's maintenance and operational status. Although the aircraft's logs indicated recent inspections, physical examinations of the Lycoming O-320-E2D engine showed that several components—including the crankshaft, camshaft, carburetor, and magnetos—did not match the part numbers or serial numbers recorded in the last maintenance logs.
Investigators found evidence of severe engine degradation, including excessive lead deposits in the combustion chambers and pistons, compression leaks at the spark plug seats, and exhaust gas leaks. Furthermore, the investigation established that the aircraft was operating significantly overweight; the total takeoff weight was approximately 1059.8 kgf, exceeding the maximum takeoff weight of 1043 kgf. The investigation also noted that the pilot was operating with an expired medical certificate and that the flight was being conducted as a commercial charter despite the aircraft being registered for private air taxi services.
Findings
- Engine Failure: The most probable cause was an engine failure following takeoff, exacerbated by inadequate maintenance and the use of unverified engine components.
- Pilot Judgment: The pilot demonstrated a lack of critical decision-making by proceeding with the takeoff despite audible engine irregularities.
- Operational Irregularities: The flight exceeded the manufacturer's maximum occupancy by carrying six people in an aircraft rated for four, and the aircraft was operating in an overweight condition.
- Lack of Oversight: The operator failed to properly supervise maintenance records, engine component tracking, and flight operations.