The technical problems occurred during the afternoon according to the EU's air traffic control authority Eurocontrol.
"Our technicians have now restored the system that was affected this afternoon. We are in the process of resuming normal operations in the London area", writes a spokesperson for the company Nats which is responsible for British airspace.
According to British media, the problem did not only affect London but several other airports around the country.
Despite the problem being solved, some delays may remain, how many are affected by the error is unclear.
"We apologize for the inconvenience this has caused", writes the spokesperson.
