What happened
On May 6, 2023, at 13:41 local time, a mid-air incident occurred in the vicinity of Monistrol de Montserrat, Barcelona, involving a EUROCOPTER AS355N, registration EC-MZH, and a DIAMOND DA4/0, registration EC-KYS.
The EUROCOPTER AS355N had departed from Sabadell Airport for a non-scheduled commercial tourist flight. While cruising at approximately 3,600 ft under Visual Flight Rules (VFR) and turning toward the north, the pilot of the helicopter spotted the DIAMOND DA40 approaching from the east. The second aircraft was performing a turn from an easterly heading toward the south at the same altitude.
To maintain separation, the pilot of EC-MZH executed an evasive maneuver consisting of a 90-degree left turn and a descent. Simultaneously, the DIAMOND DA40 performed a sharp turn toward the west, descending toward the terrain. There were no injuries and no damage to either aircraft.
The investigation
The CIAIAC investigation analyzed radar data from the Barcelona ACC, which tracked the EUROCOPTER AS355N via its active transponder. Radar records confirmed the helicopter's sudden left turn and subsequent descent and climb at 13:41. However, because the DIAMOND DA40 did not have its transponder active, its specific flight path and the exact minimum separation distance achieved could not be determined.
The incident took place in Class G uncontrolled airspace, located 900 ft below the Barcelona TMA. In this airspace, pilots are responsible for maintaining their own separation and visual lookout. The investigation also consulted a flight training organization in Igualada, which confirmed a training flight had been conducted in the area that day, though the crew was unaware of any near miss.
Findings
- The primary cause of the incident was a failure to adhere to Visual Flight Rules (VFR), specifically a lack of adequate external surveillance by both aircraft.
- The pilot of the EUROCOPTER AS355N successfully identified the conflict and performed an appropriate evasive maneuver.
- The lack of transponder activation on the DIAMOND DA40 prevented investigators from calculating the precise proximity of the two aircraft.