National Air Traffic Services (Nats) said一个技术故障flight data system at its Swanwick centre had caused the problem.
It hadnow been restored to "full operational capacity",the air traffic control company said.
The government said the disruption was "unacceptable" and demanded a "full explanation" of what had gone wrong.
...
Swanwick controls the 200,000 square miles of airspace above England and Wales, cost £623m to build, and employs about 1,300 controllers.
But the facility, which handles 5,000 flights every 24 hours,has had a troubled history.
It opened in 2002, six years after its planned commissioning date - a delay which Nats said was due to problems with the software used to power its systems.
Almost a year after it opened, a senior air traffic controller raised concerns with the BBC about health and safety standards and complications with radio communications - which he said cut out erratically.
Technical problems and computer faults hit flights in 2008 and again last summer. And, in December 2013, problems with the internal telephone system then caused further delays.
As soon as air traffic control has a problem, nothing is allowed to take off that might add to the problem.
This is unlikely to be a power problem as there are duplicate and back-up systems - including even diesel generators at a push.
It is more likely to be software, which caused the last major problem when the incoming morning crew could not switch over from night-time control system.
With aircraft out of position, or flight crews out of hours, there are likely to be knock-on problems for many flights.
