What happened
On June 7, 2010, at 06:41 UTC, a Diamond DA 40 (registration HB-SGE) departed from runway 28 at St. Gallen-Altenrhein for a training flight. Shortly after takeoff, the air traffic controller instructed the crew to maintain the runway heading to accommodate an incoming IFR flight, before later instructing them to turn left toward waypoint ZULU. The crew acknowledged this instruction.
Simultaneously, a Piper PA-46-500TP Meridian, registration D-FRAH, was conducting an IFR approach to runway 10 via the ILS. As the two aircraft approached within 1 NM of each other, the controller noticed that HB-S0GE remained on the ILS approach path. The controller immediately ordered the HB-SGE crew to turn left and alerted them to the oncoming traffic. Although both crews reported seeing each other, the aircraft crossed paths in opposite directions with a vertical separation of only 300 ft.
The investigation
The investigation examined the operational procedures at St. Gallen-Altenrhein, specifically a bilateral agreement that mandates landings on runway 10 and departures from runway 28 to manage environmental impacts. The investigation also reviewed radar data, radio communications, and the effectiveness of the tower air situation display used by the controller.
Findings
- A systemic risk exists due to the international agreement requiring opposing takeoff and landing directions, which prevents the separation of flight paths.
- The air traffic controller selected a departure procedure that placed the aircraft on a collision course and failed to sufficiently monitor the resolution of the conflict.
- The crew of HB-SGE failed to execute the instructed left turn despite confirming the instruction.
- The crew of HB-SGE did not notify the controller that they were not following the instruction.
- The controller relied on a tower air situation display that was inadequate for monitoring the distance of aircraft on the runway 10 approach.
Safety action
Safety Recommendation No. 437 advises the Federal Office of Civil Aviation (FOCA), in coordination with the airport operator and Skyguide, to implement technical or operational measures to reduce the risks associated with simultaneous IFR arrivals on runway 10 and VFR departures from runway 28.