The August bank holiday air traffic control chaos happened as Nats “collapsed their system”, Ryanair boss Michael O’Leary told MPs.
Around 2,000 flights at airports across the UK were cancelled when Nats’s system for automatically processing flight plans failed on August 28.
The company has previously said the problem was caused by a flight plan featuring two waypoints – which use letters and numbers to represent locations – with identical names.
Giving evidence to the Commons’ Transport Select Committee, Mr O’Leary said: “What fundamentally this committee needs to get the bottom of today is why did they collapse their system?”
He added: “We have written confirmation from other ATC (providers).
“(They) said they routinely and regularly receive flight plans that have duplicate waypoints in them. So this is not something complicated.
“All of their systems are designed (so that) when they receive a duplicate flight plan like that (they) reject it and they deal with it manually.
“This is routine. It happens on a daily basis both within Nats and in every other European ATC system.
“Yet on Monday August 28, bank holiday Monday here, Nats collapsed their system at 8.30am.”