What happened
On February 26, 2006, at approximately 15:57 local time, a mid-air encounter occurred near Lahr, Germany, involving two aircraft. The first aircraft, a Piper PA-34-200T, was operating under Instrument Flight Rules (IFR) on a flight from Stuttgart to Lahr. The second aircraft, an Avions Pierre Robin HR100/210 D, was operating under Visual Flight Rules (VFR) from Bad Dürkheim to Bremgarten.
The Piper PA-34-200T had been cleared by approach control for an instrument approach to runway 03 at Lahr. Shortly after being handed over to Lahr tower, the pilot was alerted by air traffic control to an unidentified aircraft on a collision course. Simultaneously, the aircraft's onboard Traffic Advisory System (TA) issued a warning. In response, the pilot increased the rate of descent, eventually achieving a vertical separation of 600 feet from the other aircraft at the same position. The pilot reported that no visual contact with the second aircraft could be established.
The Avions Pierre Robin HR100/210 D was flying a south-southwest course, passing approximately 0.5 NM west of Lahr airport. Radar data indicated the aircraft crossed the approach centerline for runway 03 at an altitude of 2,100 feet. At the time of the encounter, the minimum separation between the two aircraft was recorded as 2 NM horizontally and 200 ft vertically.
The investigation
The BFU investigation utilized air traffic control radar data to reconstruct the flight paths of both aircraft. The investigation also considered meteorological conditions, which reported good visibility with a cloud base of 2,300 feet and 2,500 feet near the Kaiserstuhl.
Findings
- The encounter took place in Class E airspace, where both IFR and VFR flights are permitted.
- Under the regulations for this airspace, IFR flights are subject to separation from other IFR flights, while both IFR and VFR pilots are to receive traffic information regarding other aircraft whenever possible.
- The close vertical separation occurred while the IFR aircraft was executing an approach and the VFR aircraft was transiting the area.