What happened
On December 18, 2013, an Aero Boero AB-115 operated by Aeroclube de Várzea Grande was performing a touch-and-go instructional flight at the Santo Antônio do Leverger Aerodrome in Mato Grosso. The flight originated from Cuiabá, with the intention of conducting training maneuvers.
During the first landing attempt on runway 36, the aircraft experienced a leftward yaw after the nosewheel made contact with the pavement. In an attempt to regain control, the instructor applied full right rudder, full power, forward elevator, and right aileron. This control input resulted in a rolling motion that lifted the left wing, causing the aircraft to lean heavily on the right landing gear. The aircraft veered off the runway and struck a tree with its left wingtip. The impact caused the aircraft to rotate counter-clockwise, leading to a second collision between the rear fuselage and another tree, which brought the aircraft to a complete stop.
The investigation
CENIPA investigators examined the aircraft's weight and balance, the flight controls, and the environmental conditions. The investigation established that the aircraft's takeoff weight was 19.2kg above the Maximum Takeoff Weight (MTOW), due to the combined weight of the two occupants and a full fuel load of 110 liters.
Physical evidence at the scene, including a single skid mark from the right tire and the height of the impact on the first tree, confirmed that the aircraft was tilting significantly toward the right side of the runway during the excursion. The investigation also noted that the propeller blade was bent forward, indicating the engine was producing power at the moment of impact.
Findings
- The aircraft was operating above its maximum takeoff weight.
- The application of flight control inputs during the recovery attempt contributed to the rolling motion and subsequent excursion.
- The instructor had relatively limited instructional experience, with approximately 43 hours of flight time as an instructor.
- The aircraft sustained substantial damage during the collision with the trees, though both occupants remained uninjured.