What happened
On September 3, 2000, an IPE-02B glider, registration PP-FJU, was performing a training flight at the Jaciara Aerodrome in Mato Grosso, Brazil. The flight was a routine instruction session involving an instructor and a student, utilizing a tow aircraft to practice emergency procedures. The specific objective of the flight was to train for an emergency takeoff procedure, where the instructor would command the release of the tow cable.
After a successful takeoff from runway 24, the tow aircraft began a slight right turn. During the climb, the instructor released the tow cable and announced a simulated engine failure. The student, who had not been briefed on this specific maneuver and had no prior training for this particular exercise, attempted to return to the opposite runway (runway 06) by initiating a left turn. During this maneuver, the glider lost altitude and entered a descending spiral. The aircraft struck the ground approximately 60 meters from the threshold of runway 06 with a steep bank and nose-down attitude. The impact resulted in two serious injuries for the crew and the total loss of the aircraft.
The investigation
CENIPA's investigation focused on the operational and organizational factors leading to the accident. Investigators examined the flight experience of both pilots, noting that while the instructor was qualified, both pilots had limited experience in this specific aircraft type. The investigation also reviewed the organizational culture of the Jaciable Aeroclube, which practiced a method of conducting unannounced emergency drills to ensure student readiness.
Technical analysis of the site revealed that the aircraft hit the ground 45 meters to the right of the runway centerline. The investigation also considered the terrain, noting a 20-meter elevation difference between the two runway thresholds, which may have caused a perceptual error regarding the aircraft's actual height during the maneuver. Furthermore, the investigation looked into the instructor's workload, noting he was performing his seventh instructional flight of the day.
Findings
- Lack of Briefing: The student had not received any prior training or a specific briefing regarding the execution of the simulated failure maneuver for this flight.
- Improper Maneuvering: The student's reaction to the unannounced failure—initiating a left turn at low altitude and low airspeed—likely led to an aerodynamic stall and loss of control.
- Instructor Complacency: The instructor's decision to perform the maneuver without warning was influenced by organizational habits and potential fatigue from conducting multiple flights in a single day.
- Organizational Culture: The aeroclube's practice of conducting unannounced drills created an unnecessary risk, as the lack of communication prevented the student from preparing for the specific altitude requirements of the maneuver.
- Perceptual Error: The elevation difference between runway thresholds may have contributed to an incorrect assessment of altitude during the procedure.