What happened
On May 8, 2012, at approximately 10:55 UTC, a Z 526 AFS-V, registration OK-CXA, was performing aerotow operations at Hosín airfield. After successfully towing a glider, the pilot attempted a descending turn to approach runway 06R. During this maneuver, the aircraft's speed decreased significantly, leading to a loss of control.
The aircraft entered a steep descent, described by witnesses as an S-shaped or spiraling path. The aircraft struck the upper canopy of two deciduous trees at an altitude of approximately 15.5 to 20 meters, which caused structural damage to the wing. Following the impact with the trees, the aircraft plunged into a nearby pond. The pilot sustained heavy injuries and was trapped in the partially submerged cockpit until bystanders arrived to provide first aid and extract him.
The investigation
The ÚZPLN investigation focused on the pilot's flight parameters, the aircraft's mechanical condition, and the sequence of events following the glider release. Investigators examined the wreckage, which showed the landing gear was retracted and the engine was functional prior to the impact. While the pilot reported attempting to increase power to recover from the descent, investigators could not definitively determine the engine's power setting at the moment of impact due to the destruction of the instrument panel.
Witness accounts indicated that the engine sound changed, appearing to increase in power just before the impact, though this may have been a result of the pilot's instinctive actions during the emergency. The investigation also noted that the pilot had limited experience specifically with the Z 526 AFS-V type.
Findings
- The pilot was legally qualified and medically fit for flight, but possessed limited experience flying the Z 526 AFS-V.
- The aircraft was in a valid state of airworthiness, and no mechanical failures were found that would have prevented controlled flight.
- The pilot attempted a non-standard, steep descending maneuver to avoid a long landing, which resulted in a loss of airspeed.
- The primary cause of the accident was the loss of airspeed during a descending maneuver due to the pilot's lack of experience with this specific aircraft type.