What happened
On May 25, 2013, an Aero Boero AB-1s aircraft, registered as PP-GIX, was performing a local flight instruction mission departing from the Tietê Aerodrome in São Paulo, Brazil. The flight was operated by the Aeroclube de Tietê with an instructor and a student on board under visual flight rules (VFR).
During the takeoff roll on runway 20, the aircraft began to veer to the left. While the student attempted to correct the course by applying rightward input, the instructor took control of the aircraft to stabilize the flight. However, the directional deviation had already compromised the aircraft's path, leading to the aircraft exiting the right side of the runway approximately 150 meters after the start of the takeoff roll. In an attempt to avoid hitting the aerodrome's perimeter fencing, the instructor executed a sharp left turn. The excursion resulted in substantial damage to the landing gear and the right wing, as well as minor damage to a propeller blade tip. Both occupants were unharmed.
The investigation
CENIPA's investigation focused on the mechanics of the takeoff roll and the pilot's response to the aircraft's instability. The investigation confirmed that the aircraft was within weight and balance limits and that all necessary certifications for the crew and the airframe were valid. The analysis examined the inherent aerodynamic and physical forces acting on a conventional gear aircraft during the takeoff phase, including torque, gyroscopic effects, and aerodynamic turbulence affecting the empennage.
Findings
- Lack of pilot experience regarding the timely application of corrective controls.
- Delayed application of controls by the instructor to prevent the loss of directional control during the takeoff roll.