What happened
On February 25, 2015, a CAP-4 aircraft, registration PP-HBK, crashed in a rural area near Campo Mourão, Paraná, during a local flight training mission. The aircraft departed from the Campo Mourão Aerodrome at 18:20 UTC with an instructor and a student pilot on board. Approximately 20 minutes into the flight, the aircraft lost control and struck the ground at a nearly 90-degree angle. The impact caused substantial damage to the engine, propeller, landing gear, wings, and control surfaces, resulting in the two fatalities of the crew members at the scene.
The investigation
CENIPA's investigation focused on the circumstances surrounding the loss of control. Investigators examined the aircraft's maintenance history, which showed the plane was within its inspection intervals, and the meteorological conditions, which were favorable for visual flight. The investigation also looked into the training curriculum of the Aeroclube de Campo Mourãon and the flight experience of the crew.
Evidence from the wreckage was difficult to analyze because the aircraft had been moved and the fuselage cut to facilitate the rescue of the victims, which prevented a full inspection of the control cables and cockpit instruments. The investigation also noted that the student pilot did not have a valid medical certificate registered with ANAC at the time of the accident.
Findings
- The primary hypothesis is that during the execution of an "S-turn over road" maneuver, excessive use of pitch and bank controls may have pushed the aircraft beyond its aerodynamic envelope, leading to a stall and spin.
- The crew lacked formal training and instruction regarding the identification and recovery of spin conditions, as the flight school's manual did not mandate such training.
- A culture of informal practices existed within the flight school, where some instructors practiced advancing maneuvers beyond what was prescribed in the manuals.
- Organizational weaknesses were identified, including a lack of effective management oversight and a failure to implement sufficient safety barriers to mitigate operational risks.
- The student pilot's training quality may have been compromised by an overconfidence in his existing knowledge and a lack of interest in formal lessons.