What happened
On September 16, 2021, a Cessna 2/10L, registration PP-JCS, was conducting a ferry flight from the Aerodrome of Santa Isabel do Rio Negro, Amazonas, to an unregistered landing site at Missão Mariauá. Approximately twenty minutes after takeoff, the aircraft's engine failed. The pilot performed a successful ditching in the Mariauá River.
The pilot was able to evacuate the aircraft through a window and was rescued by the crew of a passing boat. The aircraft remained submerged in the river for fifteen days before being recovered. While the pilot suffered no injuries, the aircraft sustained substantial damage to the engine, engine housing, and windshield.
The investigation
CENIPA investigators examined the recovered IO-520-L engine and found significant internal damage, including a hole in the engine block near cylinder number one. Analysis conducted by the Department of Science and Aerospace Technology (DCTA) revealed that the connecting rod cap of the first cylinder failed due to a fatigue mechanism. This failure caused the piston to break due to resulting stress, leading to severe engine imbalance, loss of power, and secondary damage to the engine block.
The investigation also identified a discrepancy in the engine's maintenance records. While the airframe and propeller logs were up to date, the engine logbook was found to be out of date, with a discrepancy noted between the recorded and verified time since new (TSN). Investigators could not rule out the possibility that a non-compliance occurred during non-destructive testing of the connecting rods during a previous overhaul.
Findings
- The primary cause of the engine failure was the failure of the connecting rod cap on cylinder number one due to fatigue.
- A failure to properly control engine operating hours may have allowed components to exceed their service life limits.
- There was a possibility of non-compliance during the execution of non-destructive tests during the engine's last overhaul.
- The pilot was properly qualified and the aircraft was within weight and balance limits for the flight.
Safety action
CENIPA issued a recommendation to Brazil’s National Civil Aviation Agency (ANAC) to work with the operator, Voare Táxi Aéreo Ltda., to ensure that technical maintenance control mechanisms are properly implemented, specifically regarding the tracking of aircraft and equipment utilization hours.