What happened
On January 24, 2016, an Aero Boero AB-115, registration PP-FGM, was conducting a cross-country navigation flight for a commercial pilot training program. The flight originated from Bauru (SBBU) and was destined for Londrina (SBLO), operated by Aeroclube de Londrina. On board were an instructor and a student pilot.
During the approach to Londrina, the instructor took control of the aircraft to demonstrate a three-point landing technique. During the flare, the aircraft descended abruptly and bounced on the runway. In an attempt to regain lift and execute a second touchdown, the instructor applied power. Upon the second contact with the ground, the aircraft yawed sharply to the left, performing a 18/0-degree turn on its axis and exiting the runway.
The investigation
The investigation examined the aircraft's handling characteristics and environmental conditions. The AB-115 features a conventional landing gear configuration with a high wing and a narrow track, which inherently complicates ground maneuverability. Furthermore, the aircraft's center of gravity is positioned just behind the main gear, making it susceptible to directional instability during crosswind conditions.
At the time of the incident, the METAR indicated a left crosswind of 070° at 08 knots, with a crosswind component of approximately 07 knots. While this wind was within the manufacturer's operational limits (10 to 13 knots for paved runways), the investigation noted that the left wind, combined with the engine torque produced by the power application, exacerbated the leftward yaw. Analysis of tower video suggested the initial touchdown was abrupt and uncoordinated, potentially causing the nose wheel to lose steering effectiveness and triggering the loss of control.
Findings
- The primary contributing factor was the improper application of flight controls following a bounced landing.
- The aircraft's conventional gear configuration and center of gravity made it highly sensitive to directional changes on the ground.
- The application of power during the bounce increased engine torque, which, when paired with the existing left crosswind, intensified the leftward yaw.
- The two crew members were uninjured, and the aircraft sustained no damage.