Sector Aviation

Erroneous altitude information due to failure of transponder, Sukhoi, 25 July 2016 near Castricum


On his radar screen, an approach controller at Schiphol saw that a Su-26, which was flying south along the coast at an altitude of 900 feet, had started climbing. It then flew for a brief moment into the terminal control are (TMA) of Schiphol, which has a lower limit of 1,500 feet. At the same time, an Airbus A319 – which was flying north at 2,000 feet in the TMA – turned right at Castricum to set up for a southbound approach to Schiphol. According to the radar information, both aircraft appeared to be about to intersect one another at roughly the same altitude (about 2,000 feet). The air traffic controller warned the crews of the two aircraft, and the Su-26 started to descend. The crew of the A319 continued the flight as planned. As the A319 was flying through cloud, the crew did not see the Su-26. They also stated that they had not seen a TCAS warning.

The report can be found in the Quarterly Report Aviation for the third quarter of 2016.


  • Start date 25 jul. 2016
  • End date 30 sep. 2016
  • Type investigationShort
  • Status investigationClosed

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