The delays in air traffic persisted for much Saturday before the fault could be corrected in the early afternoon.
“There was a problem with a circuit board. They have now changed it and rebooted the systems,” Klas Nilsson at Swedish aviation agency LFV (Luftfartsverket) said on Saturday afternoon.
The fault emerged at 9am on Saturday and according to LFV the problem originated in the airport’s air traffic control tower. The regular system and the backup were out out of action and the tower was rendered unable to communicate with the aircraft.
During the morning the number of takeoffs and landings that could be implemented at the airport were limited and several airports suffered delays as a result.
Johan Nordell, who was on his way to Copenhagen, was one of those who got stuck at the airport. Despite the chaos, he described the atmosphere at the airport as ordered.
“People are calm,” he told the TT news agency.
By 2pm the flights were running again but the problem continued to cause delays throughout the afternoon.
“It’s very rare that something like this happens,” said Sofia Bergström Malm at LFV.
According to Klas Nilsson it was something of a blessing that the error occurred at a time when relatively few travellers were affected. He expressed concern however at the time it took to resolve the situation.
“There is cause for LFV to review their procedures and their capacity. It is serious and really unacceptable that it should have to take so long to find and recover the problem,” he said.
LFV have said that an investigation will be launched into what caused the error and then evaluate how the incident was handled and identify where improvements can be made.
“We have two priorities in a case of this kind. One is to 100 percent guarantee flight safety, this is very important. Number two is that as soon as it is possible fix the error so that the disturbances are as minor as possible for passengers.”