What happened
On June 30, 2022, a serious air traffic disturbance occurred at the Worms aerodrome involving two light aircraft. A Cessna 172R, performing a VFR training flight, was in an initial climb from runway 24 following an aborted landing attempt. Simultaneously, a Cessna 152 was arriving from Egelsbach, flying in the opposite direction of the standard traffic pattern.
The two aircraft experienced a close approach with a minimum calculated horizontal distance of approximately 32 meters and a vertical separation of about 194 feet. The crew of the Cessna 172R reported noticing the approaching aircraft at their 11 o'clock position only when it was too late to initiate an evasive maneuver. The pilot of the Cessna 152 did not observe the encounter.
The investigation
The BFU investigation established that the pilot of the Cessna 152 had mistakenly contacted Egelsbach Info instead of Worms Info. Because the Egelsbach controller responded to the initial call without using his station callsign and failed to correct the pilot's frequency error, the pilot continued her approach to Worms while remaining on the Egelsbach frequency.
The investigation also examined the role of the Egelsbach controller, noting that he did not realize the pilot was on the wrong frequency until several minutes later, and did not notice the lack of a transponder signal on his display until the aircraft was already in the pattern. At Worms, the controller was using a monitoring screen for flight log entries, which was not in her immediate field of view, and she was unaware of the unauthorized aircraft entering the pattern in the wrong direction.
Findings
- The primary cause of the near collision was the Cessuna 152 operating in the traffic pattern in the opposite direction of the established flow without proper radio contact with Worms Info.
- Both aircraft were flying at approximately the same altitude, increasing the risk of collision.
- The physical dimensions and approach speeds of the aircraft meant that the crews had only 10 to 11 seconds of visibility, which was insufficient time to detect the other aircraft and execute an effective maneuver.
- The Egelsbach controller failed to follow standard radiotelephony procedures by not identifying his station during the initial response.
- The Egelsbach controller failed to notify the pilot that she was communicating on the incorrect frequency.
- Neither aircraft was equipped with a collision warning system.
Safety action
Following the investigation, a separate monitor dedicated exclusively to air traffic display has been installed at the Worms aerodrome to improve situational awareness for the controller.