What happened
On August 24, 2010, a Cessna 170-A, registration PT-BEQ, was conducting a flight training mission as part of an agricultural pilot training course at the Cachoeira do Sul Aerodrome (SSKS) in Rio Grande do Sul, Brazil. The aircraft was operated by Aero-Agrícola Santos Dumont Ltda. and was carrying an instructor and a student.
During the landing phase, the crew performed a standard three-point landing. However, during the subsequent landing roll, the aircraft lost control and underwent a nose-over (capotamento frontal). The aircraft came to a complete stop on its back at the center of the runway. The instructor escaped without injury, while the student sustained minor injuries. The aircraft sustained severe damage, including impacts to the propeller, engine, windshield, vertical stabilizer tip, upper cabin, and the right wing strut.
The investigation
CENIPA's investigation focused on determining why the conventional gear aircraft lost control during the rollout. Investigators confirmed that the aircraft's systems, including the braking system and wheels, were functioning normally, and there was no evidence of mechanical failure or brake seizure. The aircraft was within its specified weight and center of gravity limits.
Meteorological conditions at the time included high temperatures and the approach of a cold front, which brought turbulence and gusty crosswinds during the final approach. The investigation evaluated three primary hypotheses: the possibility of a tailwind gust, improper control inputs (including potential simultaneous braking by the student and instructor), or excessive braking by the instructor.
Findings
- The investigation identified that the nose-over occurred at the intersection of the runway and the taxiway leading to the company's parking area.
- Excessive braking by the instructor to quickly vacate the runway at the intersection was considered the most probable cause.
- Adverse meteorological conditions, specifically gusty winds and turbulence, were noted as potential contributing factors.
- There was a possibility of improper control inputs or unintended simultaneous brake application by the student.