Incident Overview
On March 30, 2014, a serious safety occurrence was recorded in the control zone of Nuremberg Airport. At approximately 13:42:40 local time, a British Aerospace AVRO RJ100 operating under Instrument Flight Rules (IFR) and an FK Lightplanes FK9 ELA ultralight aircraft flying under Visual Flight Rules (VFR) experienced a close proximity event. According to the Traffic Collision Avoidance System (TCAS) data from the RJ100, the minimum horizontal separation was approximately 0.07 nautical miles, with a vertical difference of about 200 feet. No personal injuries or material damage were reported.
Operational Context
The AVRO RJ100, operated by a Swiss airline, was on an IFR flight from Zurich to Nuremberg, carrying four crew members and 68 passengers. The FK9 ELA, a privately operated German ultralight, was flying VFR from Herzogenaurach to Donauwörth with two occupants. At 13:39:40, the air traffic controller cleared the ultralight to proceed inbound to the SIERRA reporting point. Subsequently, the controller provided the RJ100 crew with traffic information regarding the ultralight's position and altitude.
Sequence of Events
At 13:42:02, the FK9 pilot received traffic information about the RJ100 but reported that the jet was not in sight. By 13:42:21, the separation had reduced to approximately one nautical mile horizontally, with the RJ100 roughly 300 feet above the ultralight. At 13:42:29, the RJ100 crew reported a TCAS Resolution Advisory (RA) to climb. However, the pilot in command of the RJ100 stated that he perceived the FK9 to be slightly above his altitude and chose to deviate from the RA. He disengaged the autopilot and descended below the ILS glide path to pass under the ultralight visually.
Investigation Findings
TCAS data analysis revealed that at the time of the climb advisory, the FK9 was actually 200 feet below the RJ100 at a distance of 1.18 nautical miles. The system subsequently changed the instruction to descend as the aircraft converged. The flight paths crossed when the RJ100 was approximately 200 feet below the FK9. The FK9 pilot confirmed visual contact only at this moment. Both aircraft continued their flights without further incident. The investigation was conducted by the German Federal Aviation Office (BFU) and concluded summarily under § 18 FlUUG, focusing solely on factual presentation.