What happened
On Wednesday, August 6, 2003, at 20:15, an ultralight aircraft, identified as 07-IM, was involved in a fatal accident near Maringes, France. The aircraft, a GTE 503 SL / XP 15 weight-shift microlight, was being operated for private purposes. The flight involved an instructor and a student pilot.
Following an initial training session involving approach exercises, the instructor took the controls for a solo flight. After providing the student with feedback on the previous maneuvers, the instructor continued the flight for personal reasons. During this flight, the instructor applied full power to climb and began performing a series of stall maneuvers, progressively increasing the angle of attack. During one of these maneuvers, the aircraft entered a "tumbling" sequence, resulting in a loss of control and a subsequent impact with the ground.
The investigation
The investigation focused on the sequence of events leading to the loss of control and the physical dynamics of the aircraft during the maneuver. It was established that during the tumbling motion, the instructor was violently struck in the chest by the control bar of the hang glider frame. The student, who was seated in the front, attempted to stabilize the movement of the control bar using his feet, but was unsuccessful. The investigation confirmed that the aircraft inverted, leading to a structural failure of the wing. The aircraft then entered a spin and crashed into a field.
Findings
- The primary cause of the accident was intentional maneuvers performed at the limits of the flight envelope.
- The aircraft entered a "tumbling" state, a rotation around the pitch axis characterized by the aircraft flipping forward over its nose and back onto its belly.
- The centrifugal forces and inertia generated during this specific type of rotation led to the structural failure of the wing.
- The accident resulted in one fatality (the instructor) and one injury (the student), and the GTE 503 SL / XP 15 was destroyed.