What happened
On May 28, 2006, at approximately 17:23 local time, two gliders were involved in a mid-air collision while approaching runway 11 at Oca/caña Aerodrome. The first aircraft, an LS-1f with registration D-8520, was executing a standard landing pattern. The pilot of D-8520 had completed the downwind leg and performed a wide base turn to maintain separation from preceding traffic, communicating all intentions via radio.
While D-8520 was on final approach, at an altitude of approximately 30 meters and roughly 70 to 80 meters from the runway threshold, a second glider, a Duo Discus with registration BGA 4073, crossed its path. The pilot of D-8520 observed the BGA 4073 to the right, noting it was tilted at a 45-degree angle and on a collision course. The pilot of D-8520 performed an evasive maneuver by rolling the aircraft 50 degrees to the left. During this maneuver, the two aircraft made slight contact. Following the impact, the pilot of D-8520 performed a forced landing in a field adjacent to the runway. There were no injuries to either pilot, though D-8520 sustained minor damage, including a detached landing gear hatch.
The investigation
The investigation examined statements from the runway supervisor and the pilot of D-8520. The runway supervisor confirmed that D-8520 had followed the approved traffic pattern and had notified the tower of its position. Conversely, the supervisor noted that BGA 4073 did not adhere to the established pattern, entering directly onto final from a wide base. Furthermore, the supervisor stated that BGA 4073 had been notified via radio, in English, of other traffic on final approach, yet the pilot of BGA 4073 later admitted to not seeing the other glider.
Findings
- The pilot of D-8520 was correctly aligned on final approach and had followed all prescribed traffic pattern procedures and radio communications.
- The pilot of BGA 4073 entered the final approach leg without communicating intentions and failed to fly the full established landing pattern.
- The primary cause of the incident was the failure of BGA 4073 to observe local aerodrome procedures, which require pilots to follow the downwind, base, and final legs and to communicate their position and intentions.