Prosecutors launch probe of air disaster

Prosecutors want to find out if someone is responsible for the mid-air collision Keystone

Swiss and German prosecutors have launched separate investigations into the causes of Monday's mid-air collision between two aircraft that left 71 people dead.

The Bülach prosecutor’s office in canton Zurich announced on Thursday a probe for manslaughter and negligent disruption of public transport. The investigation will try to find out if Skyguide air traffic controllers acted correctly in the moments leading up to the crash between a Russian airliner and a DHL cargo jet.

“The probe will carefully investigate the exact chain of events during the time Skyguide was tracking these aircraft from Zurich airport,” said Bülach district attorney Christoph Naef. The air traffic control company is responsible for flights over the area of southern Germany where the accident occurred.

The Swiss probe will help the prosecutors decide if the controllers committed errors for which they can be held criminally liable. Proceedings were launched after the federal authorities gave their all clear, since Skyguide is a state-owned company.

Timing changed

The Germans have not asked for Swiss legal cooperation so far, but have launched their own separate investigation. According to the authorities, it is routine probe to find out if any human error led to the tragedy.

The Konstanz prosecutor is however waiting on the report from the German federal air accident investigation office (BFU) before taking proceedings further.

German investigators said on Wednesday that recordings from the Russian Tupolev’s voice recorder show the Swiss controllers told the plane’s pilots to descend just 44 seconds before the collision.

Peter Schlegel, the head of the air accident office, said investigators had cut the timing from the original 50 seconds after verifying radio records. The investigator added though that the Tupolev should have begun its descent at least 90 seconds before the crossing point.

“In fact, the TU-154 was only ordered to start descending 44 seconds before the crossing point, and the descent only began 14 seconds later after a second request,” said Schlegel. Skyguide also failed to make radio contact with the DHL pilot according to the Germans.

Russian allegations

A Skyguide spokesman said however that there is no 90-second rule for warning aircraft of imminent collision, only an international rule of thumb that says a distance of five or seven miles (eight to 11 kilometres) should be maintained between aircraft. Because of speed differences, he added it would be difficult to implement such a time-based rule.

The Russian news agency RIA Novosti renewed its attacks against the Swiss controllers on Thursday, accusing of committing a series of errors that led to the catastrophe.

According to an unnamed Russian investigator cited by the agency, the pilot of the Tupolev warned the Skyguide controllers of the risk of a collision a minute and a half before the accident. The BFU has however countered this claim, saying the recordings received from Skyguide show no message from the Russian pilot.

The Swiss air control agency refused to comment the Russian allegations.

The BFU said it would take longer to gather further data about the accident despite the recovery of all the black box recorders. The equipment and the recordings were seriously damaged and will need repairs before surrendering their secrets.

No radar problem

Skyguide has also answered criticism that its radar system was below European standards, as stated in an official report issued by the Swiss Aircraft Accident Investigation Bureau last week. The agency said there was no relation between the crash in southern Germany and problems with its radar system.

Jean Overney, the head of Bureau, added on Thursday that the radar images of the accident were clear and complete, and totally precise.

Skyguide has also confirmed it has a liability insurance policy worth SFr500 million ($334 million), guaranteed by a group of insurers. A new contract was signed on Monday.

Skyguide’s legal counsel, Othmar Lehmann, said that so far, no compensation claims could be addressed to the agency, as the question of responsibility has not been resolved.

The crash left 71 people dead, including 45 children on their way to Barcelona. Over 130 parents and relatives arrived in Germany on Thursday to see the crash site and to give investigators records that will help identify the victims. So far 69 bodies have been found.

swissinfo with agencies