What happened
On December 8, 2008, an Aero Boero AB-115, registration PP-GIV, was conducting a local flight instruction session at the Montenegro Aerodrome in Rio Grande do Sul, Brazil. The flight, operated by Aeroclube de Montenegro, involved an instructor and a student pilot performing touch-and-go maneuvers on a grass runway.
During the third landing attempt, the student pilot struggled with the flare, causing the aircraft to touch the runway multiple times before the instructor intervened to initiate a go-around. During this maneuver, a critical breakdown in cockpit coordination occurred. As the instructor attempted to take control, the student pilot applied contrary pressure to the controls. This confusion was exacerbated by a linguistic misunderstanding; the student pilot later stated he had misinterpreted the instructor's command to "yield" the controls as a command to "pitch up."
Following the loss of effective control, the aircraft entered a rapid stall and descended back toward the runway. The instructor attempted to regain control using the rudder and yoke, but the aircraft began to veer left due to torque. The aircraft left the runway surface, struck an obstacle with the left wheel, and subsequently overturned, coming to rest on its back. The aircraft sustained substantial damage, but both occupants escaped uninjured.
The investigation
The CENIPA investigation focused on the sequence of events leading to the loss of control and the effectiveness of the crew's coordination. Investigators examined the aircraft's components and found no mechanical failures contributing to the accident.
The investigation highlighted that the instructor had not been instructing since 2005 and had only recently returned to flight instruction in 2008. This lack of recent instructional experience likely hindered the instructor's ability to accurately assess the student's performance and delayed his response to the developing emergency. Furthermore, the investigation identified significant communication failures between the two pilots, specifically regarding verbal commands and cockpit resource management.
Findings
- Ineffective communication between the instructor and student pilot led to erroneous interpretations of flight commands.
- Poor cockpit coordination and improper application of flight controls during the critical phase of the go-around.
- The instructor's delayed response in assuming control was linked to an inadequate assessment of the student's flight performance.
- The student pilot's lack of experience and confusion regarding verbal instructions contributed to the loss of control.
- The instructor's recent return to instructional duties may have impacted his proficiency in managing abnormal situations with inexperienced students.