What happened
On August 9, 2020, a Piper PA-12, registration PP-DJS, was conducting a flight instruction session at the Aerobako Aerodrome (SJAK) in Sinop, Mato Grosso. The flight, operated by Aeronop Escola de Manutenção e Serviço Aéreo Especial .LTDA, carried an instructor and a student pilot. During the training session, the crew was performing landing and go-around maneuvers using the local traffic pattern.
During the flight, the instructor decided to switch the active runway from runway 11 to runway 29. This decision was made without adequate consideration of the wind direction or intensity, which actually favored operations on runway 11. While on final approach, the instructor noted the aircraft was too high and executed a sideslip maneuver to lose altitude. This maneuver resulted in an unstable approach. The aircraft touched down at a high speed and experienced a float. Attempting to stabilize the aircraft for a subsequent landing, the instructor delayed the initiation of a go-around. Consequently, the aircraft lost lift and struck the ground in a wooded area, resulting in substantial damage to the aircraft. The instructor sustained minor injuries, while the student pilot was uninjured.
The investigation
CENIPA's investigation confirmed that both pilots held valid medical certificates and appropriate licenses for the operation. The aircraft was within weight and balance limits and possessed a valid Airworthiness Certificate (CVA). However, investigators were unable to verify the most recent maintenance logs for the engine, propeller, or airframe as the technical documentation was not provided to the commission.
Meteorological data, including satellite imagery, indicated that weather conditions were otherwise favorable for flight. The investigation focused on the sequence of maneuvers, specifically the use of the sideslip technique and the decision-making process regarding runway changes and the go-around attempt.