Belgium on Thursday closed its airspace following a computer glitch linked to problems downloading data related to flight plans, said Belgocontrol, the company tasked with controlling the country's skies. Planes have not been allowed to fly over Belgium since 4:00 pm local time (1400 GMT).
"The airspace was closed for security reasons, in what we refer to as a 'clear the sky' (procedure)," Belgocontrol's spokesman Alain Kniebs told AFP, describing the incident as "very exceptional." "Some planes are grounded, others have been prevented from landing," he added.
Belgocontrol was unable to immediately quantify how many flights or passengers had been affected. According to a spokesperson for Brussels Airport, the situation should return to normal at around 6:00 pm (1600 GMT). Six Belgian airports have been impacted by the shutdown. The closure affects all jets flying at under 8,000 metres (26,000 feet) in altitude, which is the range controlled by Belgocontrol.
Any jets flying above that range are manned by Maastricht, another controller. "That means that any flight linking Denmark to Spain, for instance, will not be affected because it is flying quite high," Kniebs said.