Air controller was distracted in moments before crash

As relatives visit the crash site, the events in the control tower are slowly emerging Keystone

The lone Swiss air traffic controller on duty when two planes collided in mid-air on Monday was battling with technical problems.

German air safety investigators said on Friday that Skyguide – the Swiss government owned air traffic control company – was working on its telephone and radar systems on the night that a Russian Tupolev jet slammed into a Boeing 757 cargo plane at 11,000 metres above Lake Constance.

The revelation has added weight to growing criticism of Skyguide’s role in the disaster, which left 71 people, including 45 children, dead.

According to the German Aircraft Accident Investigation Bureau, Skyguide’s Zurich-based air traffic controller was using a temporary line while technicians worked on its regular system.

Around the same time Skyguide’s radar data processing system momentarily went out of action.

Pre-crash problems

“The problems emerged just prior to the collision of the two machines,” the bureau said.

The problems meant the air traffic controller was simultaneously monitoring two frequencies and two radar monitors. At the same time the two aircraft were on a collision course.

Between 2325 and 2333 the air traffic controller repeatedly attempted to contact an aircraft that was landing at the German port of Friedrichshafen.

Shortly afterwards, at 2334, the controller made contact with the Tupolev – just 44 seconds before it collided.

The Russian pilot began to lose altitude 30 seconds prior to impact – around the same time as the Boeing pilot began to initiate a descent after his in-flight warning system warned of the on-coming Tupolev.

“Distracted”

“It looks more and more like the Skyguide air controller was not attentive enough. He did the right thing, but he did too late,” Sepp Moser, an aviation analyst, told swissinfo.

“And he did it too late because he was distracted by communications problems with Friedrichshafen in Germany where he had the task of guiding another aircraft there.”

“He set the priorities wrong. In this situation he should not have diminished his attention for the other airplanes so much.

News of the technical problems will add to a growing perception that Skyguide was responsible for the disaster – battering Switzerland’s otherwise strong reputation for safety and precision.

As rescue crews continued searching for the bodies of two victims still missing, public attention is now focusing on why Skyguide had only one traffic controller on duty during the crash.

“A contributing factor was certainly the fact that his colleague was absent and was taking a break, and thereby disobeying internal rules of the company,” Moser said.

Investigations

Both German and Swiss authorities have launched investigations into the crash. The Zurich prosecutor’s office is investigating whether there is any evidence of manslaughter and disruption of air traffic.

Adding to the pressure on the company is the fact that the crash came just a week after Skyguide was told that its radar system was not up to European standards.

The Swiss Aircraft Accident Investigation Bureau called for improvements to the system to ensure better monitoring of minimum vertical separation distances.

Swiss media also reported claims that a 1999 report into Switzerland’s air traffic control system had raised questions about training and industry oversight.

But when contacted by swissinfo, the Swiss Federal Office for Civil Aviation declined to comment on the claims.

Good reputation

Moser told swissinfo that Skyguide had enjoyed a good reputation until this week’s disaster.

“It cannot be denied that [the company] did not handle this particular case well, but I must say that so far that Skyguide had a very, very good reputation. They were among the best in Europe

Moser said “imperfections” within Skyguide were no worse than those seen elsewhere in Europe.

by Jacob Greber