What happened
On May 21, 2024, a Cessna 172K operated by Leading Edge International Aviation Academy, Inc. experienced a total engine failure during a flight training mission. The aircraft, registration RP-C6lar6923, was performing touch-and-go maneuvers at San Fernando Community Airport (RPUS) when the engine lost all RPM during the takeoff phase of its second maneuver.
While flying at approximately 250 to 300 feet above the ground, the flight crew observed the propeller stop. The flight instructor attempted a right turn to return to the runway, but the loss of power made a runway landing impossible. The crew subsequently executed a forced landing into the waters of Barangay Canaoay. The aircraft struck the water at a 45-degree angle, causing the nose cowling to separate and the aircraft to flip onto its back after sliding 25 meters through a coral area. Both the flight instructor and the flight instructor trainee sustained minor injuries and were treated by local medical responders.
The investigation
The AAIIB investigation focused on the engine's mechanical state and the aircraft's fueling processes. Investigators performed a teardown of the Lycoming engine and examined the fuel gas strainer sediment bowl. This analysis revealed a significant amount of water within the fuel collected from the bowl. Furthermore, an inspection of the spark plugs showed that five out of the eight plugs exhibited traces of water contamination and metal oxide deposits.
The investigation also scrutinized the operator's fuel handling practices. It was discovered that the operator stored fuel in drums outside the main hangar and used an electric pump to transfer fuel to the aircraft. The process involved using a chamois cloth as a makeshift filter, which the board determined was insufficient for removing water. Additionally, the investigation found that the fuel was siphoned from drums without a process to check for sediments or moisture, and there were no formal records regarding the maintenance or replacement of the filtration materials used during servicing.
Findings
- The primary cause of the engine failure was the presence of water contaminants within the engine fuel system.
- The operator's fueling procedures lacked necessary safety protocols to prevent contamination.
- The use of a chamois cloth for fuel filtration was inadequate for ensuring the removal of water residue.
- There was a lack of documented maintenance or inspection schedules for the fuel drums and the transfer equipment used by the operator.