What happened
On September 13, 1998, an RF-5 Fournier motorglider, registration PT-PFX, departed from the Ipuã Gliding Club (SDIP) in Caçapava, São Paulo, for a local instructional flight. The aircraft was occupied by an instructor in the rear seat and a student in the front seat.
The flight's first takeoff attempt was aborted after a piece of the instrument panel detached during the takeoff roll. During the second attempt, the aircraft struggled to gain altitude due to a combination of high weight, high temperature, and a 15-knot crosswind from the left. As the crew executed a right turn to clear a nearby hill, the aircraft encountered moderate orographic turbulence. The instructor reported a sudden engine power loss; however, investigation later suggested the engine was still producing power at impact, though it may have been running irregularly. The aircraft struck a fence with its right wing and crashed violently into a hillside, resulting in the death of the student and serious injuries to the instructor.
The investigation
CENIPA's investigation revealed significant irregularities regarding the aircraft's maintenance and the club's operational oversight. Investigators found that the maintenance logs for the airframe, engine, and propeller were outdated and poorly managed. Notably, a maintenance entry for a 100-hour inspection was dated after the accident had already occurred.
Technical examination of the engine revealed that an improper repair to the magneto grounding wiring had allowed current leakage, which likely caused irregular engine operation. Furthermore, the investigation found that the club lacked effective operational control, as the student and instructor—who were also the club's president and vice-president, respectively—had very little recent experience flying this specific aircraft type. The investigation also noted that the aircraft was operating near its maximum takeoff weight under challenging meteorological conditions.
Findings
- Deficient Maintenance: Improper repairs to the magneto grounding wiring and a lack of quality control in maintenance records.
- Inadequate Planning: The crew failed to cancel the flight despite high takeoff weight and significant crosswinds that were critical for a motorglider.
- Adverse Weather: A 15-knot crosswind and orographic turbulence contributed to the loss of directional control and difficulty maintaining altitude.
- Lack of Oversight: The gliding club lacked efficient supervision of instructor currency and maintenance technician credentials.
- Low Experience: Both pilots had minimal recent experience with the RF-5 Fournier, which hindered their ability to manage the critical takeoff conditions.