What happened
On January 20, 2016, an IPE-02B glider, registration PP-FIM, was conducting a flight instruction mission at the Osório Aerodrome in Rio Grande do Sul. The flight was part of a private glider pilot training course, specifically a mission designed to simulate an engine failure (simulated emergency) where the tow cable is disconnected at an altitude of approximately 80 to 100 meters.
During the exercise, the student pilot initiated a left turn to return to the runway. While banking, the student maintained a high pitch attitude, causing a rapid loss of airspeed and leading to a stall of the inside wing. Although the instructor intervened to take control and prevent a spin, the aircraft had already lost insufficient altitude to clear nearby obstacles. The glider's left wing struck the roof of a house, and the aircraft subsequently collided with the residence's wall. The impact resulted in substantial damage to the aircraft, serious injuries to both the instructor and the student pilot, and minor injuries to a resident of the house.
The investigation
CENIPA's investigation revealed several systemic failures in the flight training process. The instructor had intentionally omitted a specific briefing for this maneuver to "surprise" the student, a practice that left the student mentally unprepared for the sudden change in flight profile. Furthermore, the student was tasked with commanding the aircraft during this specific emergency simulation without having previously been demonstrated the correct execution of the maneuver.
The investigation also identified discrepancies in the aircraft's weight and balance documentation. The ballast table found on board the aircraft differed from the manufacturer's manual. Even when using the manual's recommended ballast, the aircraft's Center of Gravity (CG) remained outside the permitted forward limit (at approximately 8% MAC, whereas the manual required 22.4% to 28%). While this CG position did not prevent control, it may have reduced maneuverability during the critical phase of the flight.
Additionally, the investigation noted a lack of managerial oversight regarding training standards and a culture where landing outside of aerodromes was treated as a normal procedure rather than an emergency, increasing the risk when flying over inhabited areas.
Findings
- Lack of briefing: The instructor did not perform a detailed briefing for the maneuver to create a surprise element.
- Inadequate training progression: The student was performing the maneuver at a low altitude without prior demonstration of the correct technique.
- Improper flight planning: The student was not mentally prepared for the sudden simulated emergency due to the lack of communication.
- Weight and balance errors: The aircraft was operating with a Center of Gravity outside of the manufacturer's specified limits.
- Instructional deficiencies: The flight training manual lacked specific details regarding the application of learning levels and the standardization of emergency simulations.