What happened
On April 29, 2005, a serious near-collision occurred approximately 2 nautical miles northwest of Berne-Belp airport. A Darwin Airline Saab 2000, operating flight DWT 501 from London City to Berne-Belp under IFR, was on final approach for runway 14. Simultaneously, a private Cessna P210N, registration HB-CIG, was conducting a VFR flight from Berne-Belp to Ecuvillable.
After taking off from runway 14, the pilot of the HB-CIG intended to perform a right turn toward the WHISKEY reporting point. However, the aircraft deviated from the published visual approach route, flying a heading that brought it onto an opposing and converging course with the incoming airliner. As the Saab 2000 descended through 2800 feet, the crew received a TCAS climb instruction. The aircraft climbed to 5600 feet to avoid the conflict. The two aircraft crossed paths with a lateral separation of approximately 0.5 NM and an altitude difference of roughly 200 feet.
The investigation
The investigation examined radar recordings from both the Zurich Multi Radar Tracker and the La Dôle radar station. While the Zurich radar data used by Berne controllers only identified the HB-CIG 13 seconds after the closest encounter, the La Dôle recordings clearly showed the flight paths of both aircraft converging prior to the incident.
Investigators also reviewed the air traffic control procedures and the Berne Visual Approach Chart. It was noted that the Berne tower was being operated by a trainee under the supervision of a coach at the time. The investigation also looked into the radar coverage, noting that the Berne tower relies on data supplied by the Zurich radar system, which failed to display the HB-CIG until after the near-miss had occurred.
Findings
- The primary cause of the incident was the lateral deviation of the Cessna P210N from its published departure route, which placed it on a converging path with the approaching airliner.
- The pilot of the HB-CIG did not follow the established procedure to turn toward the WHISKEY point, instead flying a heading that intersected the runway 14 approach axis.
- The Berne tower's radar display (TASD) did not show the HB-CIG until after the collision risk had passed, as the aircraft was only visible on the Zurich-supplied radar feed once it moved into a different sector or updated position.
- The TCAS system on the Saab 2000 functioned correctly, providing the necessary resolution advisory to prevent a collision.