What happened
On January 21, 2000, at approximately 19:00 local time, a P-56 aircraft, registration PP-GVQ, was conducting primary flight instruction near Bragança Paulista, São Paulo. The flight, operated by the Aeroclube de Bragança Paulista, involved an instructor and a student performing various stall maneuvers, including power-off (type 3) stalls.
During a power-off stall maneuver at 5,000 feet, the engine ceased operation. The instructor took control of the aircraft and attempted to reach an ultralight airstrip near a reservoir. Realizing the aircraft could not reach the runway, the instructor opted for an emergency landing in a pasture. During the final approach, the pilot attempted to avoid a fence by banking the aircraft to the left, causing the wing to strike the ground and the aircraft to capsize. The student pilot sustained serious injuries, while the instructor suffered minor injuries.
The investigation
CENIPA investigators examined the engine, fuel system, and operational procedures. While no definitive mechanical failure was identified, the investigation noted that the engine functioned normally when tested in another aircraft after the intake manifold was replaced. The investigation considered the possibility of vapor lock due to the aircraft's configuration, high temperatures, and the lack of a fuel pump, which could have interrupted fuel flow during the high-angle maneuvers.
Investigators also evaluated the instructor's decision-making and the flight planning. It was noted that the instructor did not attempt to restart the engine in flight, citing concerns about losing altitude and the need to maintain a specific glide speed. The investigation also looked into the organizational aspects of the flight school, including instructor training and recruitment processes.
Findings
- Deficient Judgment: The instructor failed to attempt an engine restart in flight and struggled to establish a safe landing site, demonstrating inadequate assessment of glide parameters and descent rates.
- Deficient Planning: The instructional flight was conducted in an area that did not provide adequate options for an emergency landing, and the maneuvers were performed with the sun directly ahead, reducing visibility.
- Human Factors: There were indications of low situational awareness and delayed perception of the engine failure by the instructor. Additionally, the organization's selection and training processes were scrutinized due to the instructor's observed impulsive reactions during the emergency.
- Operational Factors: While a mechanical cause was not confirmed, the possibility of vapor lock or an issue with the intake manifold could not be ruled out.