What happened
On April 15, 2021, an Aero Boero AB-115, registration PP-GBC, was conducting a flight training mission involving touch-and-go maneuvers at the Presidente Epitácio Aerodrome (SDEP) in São Paulo, Brazil. The crew consisted of a flight instructor and a student pilot. During the third approach, the aircraft experienced a sudden loss of engine power.
Following the power loss, the crew executed a 180-degree turn, passing over a bridge to reach the Paraná River. The instructor opted for an emergency landing on the water, approximately 20 meters from the riverbank. The impact with the water caused substantial damage to the aircraft, including a broken windshield and fuselage deformations. The instructor escaped without injury, while the student sustained minor injuries.
The investigation
CENIPA investigators examined the engine and magneto components to determine the cause of the power loss. Upon inspection of the magnetos, investigators found oxidation and carbonization on the internal contact points (platinados). While the engine passed a functional test after the contacts were cleaned, the presence of carbon deposits suggested a potential failure in the ignition system.
Furthermore, the investigation identified inconsistencies in the maintenance records of the maintenance organization responsible for the magneto overhaul. Discrepancies were noted regarding the traceability and quantities of replacement parts used during the service, making it impossible to rule out maintenance-related contributions to the component failure. The investigation also noted that the flight instructor was managing the controls while the student was distracted by using a mobile phone to take photographs during the approach.
Findings
- Carbonization of magneto contact points was identified as the primary factor leading to the engine power loss.
- Distraction and lack of cockpit discipline contributed to the incident, as the student's use of a mobile phone for photography during a critical phase of flight may have hindered effective cockpit coordination.
- Inadequate emergency procedures in the flight school's manuals, specifically regarding power loss after takeoff and the lack of a "sterile cockpit" policy, contributed to the severity of the outcome.
- Maintenance traceability issues were identified regarding the parts used in the magneto overhaul.