What happened
On June 23, 2018, at approximately 20:00 UTC, a Cessna 172B, registration PT-BNT, was performing a repositioning flight from Bomar (SJXI) to Aquiraz (SJCM) in Ceará, Brazil. The flight was being operated by a single pilot. During the descent to 500 feet, as instructed by air traffic control, the aircraft's engine suffered a significant loss of power, dropping to idle.
After the engine failure, the pilot performed a 360-degree turn to evaluate landing options and initially intended to land on the sandy beach. However, upon observing bystanders moving from the water toward the shore, the pilot opted to execute a forced landing in the sea. The aircraft impacted the water near Mucuripe Beach, causing the plane to capsize. The aircraft sustained substantial damage, while the pilot sustained minor injuries.
The investigation
The CENIPA investigation focused on the engine's fuel, ignition, and lubrication systems. While the fuel lines and controls were found to be intact, investigators identified discrepancies in the ignition system, noting that two of the six ignition cables on the right magneto had different terminal shapes.
Furthermore, the investigation revealed a discrepancy regarding the aircraft's carburetor. The engine's Type Certificate Data Sheet (TCDS) specified a Marvel-Schebler MA-3SPA model, but the aircraft was equipped with a Precision Airmotive MA-3PA model. This mismatch made it impossible to establish the full traceability of the component. Additionally, the maintenance records for the aircraft's recent 100-hour inspection were found to contain several items marked as completed that were not applicable to this specific aircraft model. The investigation also noted that the aircraft's engine, propeller, and airframe logbooks were lost at the accident site.
Findings
- The engine experienced a power loss that could have been related to carburetor failure.
- Inconsistent maintenance documentation and the use of a carburetor model not authorized by the engine's TCDS were identified.
- Two ignition cables on the right magneto featured non-standard terminal shapes.
- The maintenance organization's records for the last inspection included non-applicable items signed by the technical lead.
Safety action
CENIPA issued a recommendation to the National Civil Aviation Agency (ANAC) to oversee the maintenance organization involved, ensuring they possess the necessary resources and strictly adhere to technical manuals and capability lists for servicing Cessna aircraft.