The technical failure that led to hundreds of flight cancellations and severe disruptions for thousands of people traveling in and out of Britain last week resulted from a 'one in 15 million chance,' the air traffic control service said on Wednesday.
The report says that the air traffic control system encountered two separate pieces of navigational data in one aircraft's flight plan that had the same name. The system's primary and backup computer systems shut down to avoid passing inaccurate information to the controllers.