Two Japanese air traffic controllers have had their appeal against conviction for professional negligence overturned by Japan's Supreme Court.

Their prison sentences were suspended, but public service regulations require that they are dismissed from their jobs.

The International Federation of Air Traffic Controllers' Associations (IFATCA) has condemned the court decision for being inimical with ICAO just culture standards to which Japan is a signatory. IFATCA adds that it also goes against the ICAO convention that information gathered by an official accident or incident investigation should not be used as prosecution evidence in court, because it damages the ability of investigators to obtain cooperation from those involved in the event.

The two air traffic controllers were on duty at the time of a near-collision incident between two Japan Airlines aircraft, a Boeing 747 and a McDonnell Douglas DC-10, above Yaizu on 31 January 2001.

Trainee air traffic control officer Hideki Hachitani was directing the flights under the supervision of Yasuko Momii when a conflict arose between the two aircraft. Hachitani had cleared the 747 to climb to FL390, but 2min later the DC-10, whose path was going to cross that of the 747, called at FL370. Hachitani noticed the conflict, but cleared the 747 to descend when he intended to tell the DC-10 to do so.

Immediately after this instruction both crews received a traffic alert and collision avoidance system resolution advisory, the 747 to climb and the DC-10 to descend. The DC-10 crew followed the RA and descended, but the 747 crew ignored the RA and carried out the ATC instruction to descend. Collision was averted by the 747 crew, who gained visual contact with the DC-10, putting their aircraft into a steep descent, injuring 100 people on board.

Since that incident, Japan has adopted the ICAO standard procedure in which a TCAS RA takes precedent over a controller's instruction.

On their first trial in a District Court, Hideki and Momii had been found not guilty on the grounds that other mistakes or misjudgements besides their own contributed to the event.

But the prosecution took the case to the High Court, which delivered a guilty verdict which the Supreme Court upheld against an appeal.

Source: Air Transport Intelligence news