What happened
On February 4, 2010, an instructor and a student pilot were conducting a flight check for a private pilot license, departing from Blumenau Aeroclube (SSBL). The flight plan involved a closed navigation circuit with intermediate landings at Lontras (SSLN) and Rancho Sumidouro (SSRS).
During the approach to the runway at Rancho Sumidouro, the instructor requested that the student perform a short-landing maneuver. Despite the instructor warning of potential thermal currents due to high ambient temperatures of approximately 35°C, the student reduced power on final approach with flaps fully extended. At this moment, the AB-115 experienced a sudden loss of lift and sank abruptly. Although the student attempted to apply full power, the aircraft struck the ground at the edge of the runway plateau before reaching the paved surface. The aircraft subsequently bounced and landed 50 meters further down the center of the runway. Both occupants were unharmed, but the aircraft sustained severe damage to the propeller, engine, and main landing gear struts.
The investigation
CENIPA's investigation revealed significant discrepancies in the student's training records. Although the instructor had reviewed the student's files, he failed to notice that several required training missions had not been completed and that the student had progressed to advanced phases of the course without meeting all prerequisites. Furthermore, the investigation found that the student's total flight time was being calculated using review hours, which should not be included toward the minimum hours required for a checkride.
Organizational deficiencies were also identified at the flight school. The aeroclub lacked an instruction coordinator to supervise the training process and was not actively implementing its Accident Prevention Program (PPAA). Additionally, the lack of runway markings at the private airfield contributed to the crew's difficulty in accurately judging the touchdown point.
Findings
- Instructional failures: The absence of an instruction coordinator allowed the student to be presented for a checkride without being properly prepared.
- Inadequate risk assessment: The crew failed to account for the high risk of downdrafts during a short-landing maneuver in high-temperature conditions.
- Lack of oversight: Inadequate management supervision at the aeroclub and insufficient oversight by ANAC allowed training irregularities to persist.
- Infrastructure issues: The absence of runway threshold markings contributed to an excessively short approach.
- Meteorological factors: The sudden loss of lift was likely caused by unexpected downdrafts/thermal currents.