What happened
On April 8, 2000, a Cessna C-120, registration PT-ATQ, was performing a flight for pilot re-adaptation at the Jacarepaguá Aerodrome in Rio de Janeiro. The flight involved a student pilot and an instructor. During a series of touch-and-go exercises, the student pilot executed a heavy landing that caused the left main landing gear wheel to detach from the aircraft.
Upon realizing the gear had failed, the instructor took control of the aircraft and declared an emergency. To mitigate the risk of a more violent impact, the instructor decided to perform a three-point landing on the asphalt runway at a very low airspeed. During the landing attempt, the aircraft struck the ground with enough force to cause it to capsize, sliding on its upper wing surface before coming to a stop inverted on the runway. Both occupants were uninjured, though the aircraft sustained severe damage, including an irrecoverable propeller and significant damage to the engine, fuselage, and landing gear.
The investigation
CENIPA's investigation focused on the mechanical failure of the landing gear and the operational circumstances of the flight. Investigators examined the detached components and found that the left main gear attachment axle exhibited a high degree of corrosion. This corrosion significantly reduced the component's resistance to impact.
The investigation also reviewed the aircraft's maintenance history. The aircraft had been grounded for three years prior to the incident. While an inspection had been performed in January 2000, the investigation found that the specific inspection of the landing gear axle, which is required by the manufacturer every 100 hours, had been omitted. Furthermore, the instructor's lack of specific experience with the C-120 model and the student's lack of recent flight experience were analyzed as contributing to the heavy landing impact.