What happened
On December 8, 2018, at Fuentemilanos Aerodrome (LEFM) in Spain, a collision occurred between two Grob G-103A Twin II Acro gliders during a training session. The first aircraft, registration EC-DPB, was being operated by a student pilot performing a solo landing on runway 34. The second aircraft, registration EC-DPE, was positioned on the ground within the runway safety area, just before the threshold, as the crew prepared for a subsequent tow flight.
During the final approach, the aircraft in flight descended significantly below the required altitude. The underside of EC-DPB struck the T-tail, cockpit, and right wingtip of the stationary EC-DPE. The impact also struck the instructor standing beside the aircraft on the ground. While the student pilot in EC-DPB remained uninjured, the instructor sustained fatal injuries following the impact. The aircraft on the ground suffered substantial structural damage, including a broken T-tail, a ruptured cockpit canopy, and a longitudinal tear in the right wing.
The investigation
The CIAIAC investigation examined the flight profiles, the positioning of the aircraft, and the operational procedures at the aerodrome. Investigators reviewed the flight history of the student pilot, who had completed 75 flights, and the extensive experience of the instructor involved. The investigation also analyzed the environmental conditions, which were characterized by unlimited visibility and light northwest winds.
Technical analysis of the wreckage confirmed that the impact sequence involved the main wheel of EC-DPXB hitting the T-tail, followed by the right wing underside hitting the cockpit, and the wingtip wheel striking the instructor. The investigation also looked into the practice of positioning gliders near the runway threshold for tow preparations, a common but high-risk operational habit at this location.
Findings
- The primary cause of the accident was the execution of a final approach at an altitude significantly below the required height.
- A contributing factor was the presence of the second glider and its crew in the immediate vicinity of the runway threshold and along the runway centerline.
- The student pilot may have experienced "focused attention," where the effort to precisely hit a specific touchdown point led to a neglect of altitude monitoring, potentially resulting in the improper use of air brakes.
- The instructor's position, with his back to the approaching aircraft, delayed his ability to react to the imminent danger.