What happened
On 28 November 2018, a Piper PA32-301, registered F-OJSN, was conducting a cross-country flight from Canefield airport in Dominica to Pointe-à-Pitre, Guadeloupe. The aircraft was carrying a pilot and two passengers.
While flying near the Les Saintes archipelago, the pilot noticed slight vibrations in the airframe. Believing the vibrations might be caused by an improperly secured rear door, the pilot decided to divert to Les Saintes aerodrome. As the aircraft approached the runway, the vibrations intensified. During the final approach over the Baie des Saintes, the pilot heard a noise resembling an explosion, observed smoke in the cockpit, and noted a drop in oil pressure and temperature.
Faced with the risk of attempting a landing at Les Saintes—an aerodrome characterized by nearby obstacles, terrain, and dwellings—the pilot opted for an emergency water landing. The pilot performed a precautionary approach without flaps, maintaining a nose-up attitude to avoid boats in the bay. The aircraft made contact with the water, gliding across the surface before coming to a stop. The three occupants successfully evacuated via the wings and were rescued by nearby boats before the aircraft sank.
The investigation
The investigation focused on the mechanical state of the engine and the sequence of the failure. The aircraft's Lycoming IO-540-K1GS engine was examined by a maintenance workshop. Investigators analyzed the wreckage to determine the origin of the vibrations and the sudden engine shutdown.
Findings
Technical examination of the engine revealed that a piece of the engine casing had been torn away near a rear left attachment point. The investigation established that the failure of a cylinder 6 rod led to the rupture of the camshaft and subsequent damage to the engine casing. This failure caused the loss of oil, which spread over the airframe, and produced the intense vibrations experienced by the pilot. While the mechanical failure of the rod was identified as the primary cause of the engine's destruction, the specific reason for the rod's failure could not be determined.