Two air-traffic controllers who failed to attempt to contact the doomed Helios aircraft when it entered Greek air space are to face disciplinary charges for negligence after an internal investigation by the Civil Aviation Authority yesterday ruled that they had a case to answer. The Cypriot Boeing 737 had been in Greek air space for around an hour before efforts were made to contact it by the two controllers on duty, despite having been informed by their Cypriot counterparts that there was a problem with the plane. Greek authorities said the two men should have tried to communicate with the pilot as soon as the plane crossed into Greek air space, as is standard practice, rather than rely simply on visual contact over the radar and the fact the plane was following its normal flight plan. However, Greece’s Civil Aviation Authority ruled that their alleged negligence did not have an impact on the plane crashing north of Athens and killing all 121 people on board. The authority also concluded that the rest of its staff had acted properly.