What happened
On September 6, 2021, a Neiva 56-C-1, registration PP-HPT, was conducting a flight instruction mission departing from Aeródromo Fazenda Irohy in Biritiba Mirim, Brazil. The crew consisted of a flight instructor and a student pilot. During the flight, the instructor initiated a simulated high-altitude engine failure exercise (known as "Emergência Alta") at approximately 1,200 feet.
During the execution of the procedure, the student pilot moved the magneto switches, which resulted in the actual shutdown of the engine. Although the instructor attempted to restart the engine by resetting the magnetos and attempting to use relative wind to rotate the propeller, the engine failed to restart and the propeller came to a complete stop. Realizing the aircraft could not reach the airfield, the instructor performed a forced landing in an unprepared, marshy field. The aircraft struck the terrain and overturned, resulting in substantial damage to the airframe. One crew member sustained minor injuries, while the other remained uninjured.
The investigation
The CENIPA investigation examined the cockpit procedures, the student's training progress, and the flight school's manual. The investigation found that the student pilot, who was on his fifth training mission, had incorrectly interacted with the magneto controls. The investigation considered two possibilities: an intentional error due to a lack of knowledge regarding the consequences of the action, or an inadvertent movement caused by the physical positioning of the switches, which were located above the student's left side and difficult to see.
Investigators also reviewed the flight school's procedures manual. It was noted that the manual's instructions for the engine failure exercise were potentially confusing, as they instructed the student to "execute" certain checklist items that did not align with the aircraft manufacturer's manual. Furthermore, the investigation found that the engine restart procedures prescribed by the flight school were ineffective for this specific aircraft model, as the manufacturer had not designed the engine for in-flight restarts after a complete propeller stop.
Findings
- Inadequate communication and cockpit coordination between the instructor and the student pilot.
- Inaccurate training procedures within the flight school's manual, which lacked clarity and did not align with the aircraft's manufacturer specifications.
- Student error involving the incorrect manipulation of the magneto switches, potentially exacerbated by the physical placement of the controls.
- Incomplete maintenance records, as the logbooks for the airframe, engine, and propeller were found to be outdated.