What happened
On November 18, 2006, at approximately 14:16 UTC, two single-engine aircraft experienced a serious near mid-air collision within the Rotterdam control zone. The first aircraft, an Avion Robin DR 400/120 with registration PH-SVM, had departed Rotterdam Airport for an overland flight to Seppe Airport, following a standard departure route at 1,500 feet. Simultaneously, a Cessna 172P, registration PH-JNA, was conducting a local flight and had requested a direct route to the city for landing.
During the flight, the pilot of PH-SVM encountered the Cessna 172P at a perpendicular angle. The pilot of PH-SVM reported that the two aircraft passed within approximately ten meters of each other at roughly the same altitude. Following the encounter, both aircraft completed their flights safely, landing at their respective destinations.
The investigation
The investigation, based on findings from the Air Traffic Incident Commission (ATIC), examined radar data and radio transcripts. It was established that the pilot of PH-SBV was not visible on radar because their transponder was not active. Conversely, the PH-JNA was using transponder code 0000, a code assigned by Rotterdam Tower to VFR flights deviating from standard routes to ensure radar visibility for separation from IFR traffic.
Investigators found a discrepancy between the pilot's radio position reports and actual radar tracks. While the pilot of PH-JNA reported being at a specific waypoint, radar data placed the aircraft significantly north of its reported position. Furthermore, the air traffic controller had authorized a route that the pilot did not strictly follow, leading to an unexpected conflict in the airspace.
Findings
Several contributing factors led to the near collision:
- The pilot of PH-JNA deviated from the specific route intended by the air traffic controller.
- The air traffic controller did not recognize the deviation because the pilot's position reporting was inaccurate, and the controller failed to verify the aircraft's position via radar.
- Because the controller was unaware of the route deviation, no traffic information was provided to either aircraft.
- The see-and-avoid principle failed, as the pilot of PH-JNA did not detect the approaching PH-SVM despite the extremely close proximity.
Safety action
The investigation noted that the limitations of the see-and-avoid principle are well-documented in aviation literature, yet such limitations receive relatively little attention in flight training curricula. The report highlighted that the responsibility for separation between VFR aircraft in Class C airspace rests with the pilots, yet the breakdown in both communication and visual detection created a high-risk situation.