What happened
On June 29, 2019, a Cessna 172K, registration PT-DNE, was conducting a flight training mission for a commercial pilot candidate. The flight originated from Canela Aerodrome (SSCN) in Rio Grande do Sul, Brazil, involving an instructor and a student pilot. After performing various touch-and-go maneuvers at several aerodromes, the crew returned to SSCN for landing.
During the final approach to runway 24, the aircraft encountered significant turbulence and wind gusts. The approach was flown with flaps retracted on a long final. As the aircraft touched down, it drifted to the left side of the runway, veered off the pavement, struck a drainage ditch, and subsequently overturned. The aircraft sustained substantial damage, but both occupants escaped the wreckage uninjured.
The investigation
CENIPA's investigation focused on the meteorological conditions and the decision-making processes of the crew and the flight club. Investigators analyzed weather station data from INMET, which revealed that at the time of the accident, sustained winds were approximately 19.81 knots with gusts reaching 30.71 knots. This significantly exceeded the manufacturer's guideline, which suggests that an average pilot can safely control the aircraft in crosswinds of up to approximately 13 knots.
The investigation also examined the organizational structure of the Aeroclube de Canela. It was found that while the instructor was aware of an approaching cold front, the decision to proceed with the flight was made despite known adverse weather. Furthermore, the investigation identified a lack of managerial oversight, as no responsible official was present at the club to monitor or restrict flight operations during the period of high winds.
Findings
- The primary contributing factor was the adverse meteorological conditions, specifically high-intensity crosswinds and gusts that exceeded the operational capability of the pilot.
- Flawed decision-making and flight planning contributed to the decision to continue the mission despite the weather.
- Organizational failures within the flight club allowed for high levels of instructor autonomy without adequate support or supervision to ensure safety parameters were respected.
- The student pilot experienced physical malaise due to turbulence, which impacted the cockpit environment during the final stages of the flight.