What happened
On April 28, 2018, at the Bremgarten aerodrome, a near-collision occurred between two aircraft operating under visual flight rules. A Beech 36TC was on final approach to the active runway 05, maintaining radio contact with the airfield controller. Simultaneously, a Dassault Falcon 900B was approaching the airfield for a landing on runway 23, which was not the active runway.
The crew of the Dassault Falcon 900B discovered approximately five minutes before landing that their Flight Management System contained an incorrect destination airport. In an attempt to correct the error, the pilot flying decided to land on runway 23. This spontaneous decision created significant time pressure and resulted in an unstabilized approach. The crew failed to establish the proper landing configuration in a timely manner, triggering gear and sink rate warnings shortly before touchdown.
As the Dassole Falcon 900B continued its approach, the pilot of the Beech 36TC spotted the oncoming aircraft. After consulting with the airfield controller, the pilot of the Beech 36TC initiated a go-around to the north, successfully preventing a collision. Radar data indicated the two aircraft passed with a vertical separation of approximately 225 feet.
The investigation
The BFU investigation focused on the actions of both crews and the communication failures between the Dassault Falcon 900B and the airfield controller. The investigation established that the Dassault Falcon 900B crew was using an outdated radio frequency, as they had failed to tune to the new frequency implemented earlier that year. Consequently, the crew had no communication with the Bremgarten controller and was unaware of the active runway or the presence of the Beech 36TC.
Analysis of the cockpit voice recorder from the Dassault Falcon 900B revealed that the crew's focus was heavily diverted by the FMS error and the subsequent rushed approach. The investigation also noted that the aircraft lacked a Flight Data Recorder, which limited the ability to analyze specific flight parameters.
Findings
- The primary cause of the incident was the lack of adequate airspace observation by the Dassault Falcon 900B crew.
- The crew's decision to switch to runway 23 without a proper briefing or stabilized approach criteria led to self-imposed time pressure and a failure to monitor the surrounding traffic.
- The crew was operating on an incorrect radio frequency due to inadequate flight preparation.
- The pilot of the Beech 36TC successfully applied the "see and avoid" principle to prevent the collision.