Don't midair them when they are loaded with children.....
Swiss air crash controller killed ;
The air traffic controller on duty when two planes collided over southern Germany in July 2002 has been killed at his home in Zurich.
Police said an unknown man called at the home of the controller and, after a brief exchange of words, stabbed him.
They said they could not rule out a link between the killing and the crash.
Seventy-one people were killed when a Russian charter aircraft collided with a cargo plane. Most of the dead were Russian schoolchildren.
Police spokesman Marting Sorg said the victim died at his home.
He added that officers were looking for a man in his 50s who spoke broken German.
The controller, a 36-year-old Danish national who has never been named, was employed by Skyguide, the Swiss air traffic control system in charge of monitoring parts of German airspace just across the border from Switzerland.
Air accident investigators have said the controller told the pilot of the Russian plane to descend when its onboard collision warning equipment was telling it to climb.
Skyguide has been criticised for its role in the air accident after investigators revealed that only one controller was on duty when it happened. His partner was on a break.
Investigators also discovered that the agency's collision alert system was out of action for maintenance, and work on its telephone system meant a warning call from German colleagues never got through.
In a statement released after the accident, the air traffic controller acknowledged that errors in the traffic control network contributed to the disaster.
Skyguide said it was appalled by the killing and that its employees were "in shock".
It has temporarily reduced by 40% the number of planes it is allowing into the airspace it controls because of the impact of the killing on the other air traffic controllers.
The company said employees and the controller's family were receiving special counselling.
Zurich police had helped organise special protection, it added.