What happened
On December 30, 2023, a Cessna C-172, registration LV-GSL, operated by Escuela de Vuelo Chascomús, was conducting a solo flight for instructional purposes. The flight was intended to simulate a private pilot license examination. After departing from the Chascomús aerodrome, the aircraft climbed to approximately 500 feet to begin the initial approach circuit.
During this phase, the student pilot noticed abnormal noises and vibrations coming from the front of the aircraft. In response to the engine malfunction, the pilot reduced power and attempted to return to the runway. However, due to high airspeed and the aircraft's proximity to the ground, the pilot was unable to complete the necessary turns to align with the runway axis. To avoid a potential loss of control, the pilot opted to land in a clear field near the runway. Upon touchdown, the aircraft traveled 118 meters before striking a perimeter fence and flipping over. The pilot exited the aircraft without injuries, though the aircraft sustained significant damage.
The investigation
The investigation focused on the airworthiness of the aircraft and the pilot's emergency procedures. Investigators examined the engine, propeller, and fluid samples. While the propeller damage was consistent with the engine not delivering power at the time of impact, the exact origin of the power loss could not be definitively determined.
Laboratory analysis of the fuel showed it was appropriate for use, but the analysis of the engine oil revealed critical issues. The oil exhibited an inadequate viscosity index and contained high concentrations of iron and copper, indicating internal engine wear. Furthermore, investigators identified discrepancies in the aircraft's maintenance logs, noting a discontinuity in the recorded flight hours and a mismatch between the annual inspection records and the aircraft's actual service history.
Findings
- The student pilot experienced engine abnormalities during the initial approach and executed an emergency landing in a field to avoid a loss of control.
- The engine oil was not fit for service due to improper viscosity.
- The aircraft's maintenance records contained a discontinuity in flight hour documentation.
- Internal engine wear was present, as evidenced by metallic particles in the oil analysis.