What happened
On 21 October 2018, a Cessna Reims-Aviation F152, registered F-GEMS, was performing a cross-country flight from Granville - Mont-Saint-Michel to Cambrai-Niergnies. While climbing through approximately 4,500 ft, the pilot experienced intense vibrations and a sudden loss of engine power.
Following the engine failure, the pilot shut down the engine and declared an emergency on the local frequency. Unable to return to the departure airfield, the pilot identified a large field for an off-airfield landing. During the short final approach, the aircraft's right wingtip struck the branches of a tree at the edge of the field. The subsequent landing caused the left wing to strike the ground, resulting in the destruction of the aircraft. There were no fatalities among the two occupants.
The investigation
The BEA examined the Lycoming O-235-L2A engine to determine the cause of the power loss. Physical inspection revealed that the right rear cylinder (cylinder No 3) had separated from the crankcase. The investigation found that the cylinder rod was heavily damaged, specifically noting that the rod small end had broken. This failure led to the destruction of the cylinder base and the tearing of several studs from the crankcase due to extreme overload.
Investigators also reviewed the maintenance history of the engine. At the time of the accident, the engine had logged approximately 2,800 operating hours since its last major overhaul. The manufacturer-specified Time Between Overhaul (TBO) for this engine type is 2,400 hours.
Findings
- The primary cause of the engine failure was the rupture of the small end of the cylinder No 3 rod.
- The engine had exceeded its recommended TBO by approximately 400 hours, which may have contributed to the mechanical failure.
- The pilot may have miscalculated the aircraft's glide performance following the engine shutdown, leading to an approach altitude that was too low to clear the vegetation.