What happened
On July 31, 2005, a Neiva 56-C, registration PP-GUT, was performing a local flight training mission at the Bragança Paulista Aerodrome (SBBP) in Brazil. The aircraft was occupied by an instructor and a student pilot.
During the takeoff roll, the aircraft began to deviate from the runway centerline toward the right. As the tail lifted, the student pilot attempted to correct the deviation, which induced a strong yaw to the left. The instructor then attempted a corrective input, causing a subsequent yaw to the right. In response, the student pilot applied opposing controls. Despite verbal commands from the instructor to relinquish control, the student continued to apply pressure to the flight controls. The aircraft eventually lifted off while off the runway centerline, veering toward the left side of the strip. The aircraft proceeded to descend into an embankment and collided with trees, resulting in severe damage to the airframe, including a broken wing, a broken tail, and engine mount damage. Both occupants emerged uninjured.
The investigation
CENIPA's investigation focused on the coordination between the two occupants and the effectiveness of the flight instruction techniques. The investigation established that the aircraft was in a valid state of airworthiness and within weight and balance limits.
Investigators examined the cockpit dynamics, noting that while a briefing had been conducted regarding the transition of control, the practical application during the critical takeoff phase was flawed. The investigation also reviewed the instructor's training records, noting a lack of detailed documentation regarding his specific training in briefing techniques and student evaluation processes at the aero club.
Findings
- Improper control application: The pilots failed to effectively manage the aircraft's deviation from the runway centerline.
- Lack of cockpit coordination: The simultaneous use of flight controls by both the instructor and the student was not properly coordinated, leading to conflicting inputs.
- Failure to relinquish control: The student pilot did not obey the instructor's verbal commands to take over the controls, instead applying an exaggerated and abrupt input that led to the loss of control.
- Instructional deficiencies: There were indications that the instructor's training may not have sufficiently covered advanced briefing and instructional techniques, specifically regarding the management of dual controls during critical phases of flight.