What happened
On August 23, 2014, a GLASFLUGEL Sd Libelle 201B glider, registration EC-HJY, was performing a local private flight near the Santa Cilia aerodrome in Jaca, Huesca. During the flight, while at approximately 400 meters above the ground, the pilot experienced a sudden mechanical failure. The rudder pedals and their supporting assembly suddenly shifted forward toward the nose of the aircraft and became jammed.
This movement caused the right rudder pedal to be held in a fully depressed position, resulting in a continuous and severe rightward yaw. To maintain a straight flight path and prevent a descending spiral, the pilot had to use significant left bank to counteract the rudder deflection. Due to the loss of directional control, the pilot was unable to perform the turns necessary to reach suitable landing fields and instead opted for an emergency landing in the dry bed of the Estarrula River.
During the final approach, the left wingtip struck a pine tree on the riverbank. The impact caused the left wing to detach, and the remaining fuselage struck the hillside, causing the right wing to also detach and the fuselage to break near the tail. The pilot sustained serious injuries, including head and thoracic trauma.
The investigation
The investigation focused on the sudden movement of the rudder pedals and the subsequent loss of control. Investigators examined the rudder control cables and the structural integrity of the pedal assembly. While a broken right rudder cable was found, analysis confirmed it had snapped due to impact forces during the crash, not during flight.
Technical examination of the aircraft's interior revealed that the fiber base, which is bonded to the fuselage with epoxy resin, had experienced progressive degradation and tearing. The investigation also reviewed the flight data from the onboard logger, which confirmed the aircraft's descent rate and the pilot's efforts to maintain a straight trajectory.
Findings
- The primary cause of the accident was the detachment and tearing of the fiber base that anchors the rudder pedals to the fuselage.
- The failure was triggered by the force exerted by the pilot, who was using both feet to press the pedals simultaneously to adjust his seating position.
- This structural failure allowed the entire pedal assembly to slide forward and wedge against the front of the cockpit, mechanically locking the right pedal in the depressed position.
- The pilot's decision to fly a straight path to the riverbed was a necessary response to the inability to execute turns without entering an unstable spiral.
- The rapid emergency notification by the pilot and the quick response from medical services were critical factors in the pilot's survival.