The computer error that caused the skies over London to be cleared of planes had never been seen by engineers before, according the company in charge of the system.
Air traffic control firm Nats said the computer error had restricted air traffic controllers’ ability to deal with high volumes of aircraft.
Nats said its systems were up and running against last night but that knock-on effects were still affecting airports today.
A company spokesperson explained that fault occurred when controllers tried to transition between two “states” of their system.
"Swanwick controller workstations provide a number of tools and services to the controller to enable them to safely control a high volume of air traffic,” the spokesperson said.
"In normal operations the number of workstations in use versus in standby fluctuates with the demands of the traffic being controlled.
"In this instance a transition between the two states caused a failure in the system which has not been seen before,”
“The failure meant that the controllers were unable to access all of the data regarding individual flight plans which significantly increases their workload.”
Travel agenda - 12/12/2014
Travel agenda - 12/12/2014
1/8 Wee dram
2. Wee dram
Wine travel specialist Arblaster & Clarke is branching out with a new whisky tour in 2015. Taste your way around the Scottish Highlands, experiencing the whisky producing areas of Speyside and the Isle of Skye and taking part in a blending masterclass. The four-night tour departs 16 September from £2,335pp.
2/8 Route to Rouen
3. Route to Rouen
Set sail from Portsmouth on 29 December for a new year river cruise. A special sailing aboard Brittany Ferries' flagship, Pont Aven, will travel up the Seine to the historic city of Rouen, where she moors for 28 hours – allowing plenty of time to explore. The arrival back in Hampshire is at 3pm on 1 January. The price is from £159pp.
3/8 Dream team
4. Dream team
Virgin Atlantic has revealed three more routes on which its ageing Airbus A340 fleet will be replaced by the latest Boeing 787 Dreamliner. Starting on 25 October next year, routes from Heathrow to Dubai, Shanghai and Johannesburg will be operated by the new aircraft.
4/8 Zim Zam plan
5. Zim Zam plan
Zimbabwe and Zambia have launched a new "Univisa," valid for both countries for up to 30 days, which will significantly cut the cost of red tape. UK passport holders can obtain it on arrival at Livingstone, Lusaka and Harare airports, and at the border posts of Victoria Falls and Kazungula.
5/8 Pack your skis
6. Pack your skis
British Airways is launching two new short-haul routes from Gatwick aimed at skiers. Flights to Friedrichshafen in southern Germany begin tomorrow, followed by Grenoble (a two-hour drive to the French Alps) on 20 December. Both services will operate until the end of the ski season in April 2015.
6/8 Fiennes time
7. Fiennes time
Explorer Sir Ranulph Fiennes is to open the weekend-long Adventure Travel Show on 17 January at London's Olympia. Fiennes will also be available for a meet-and-greet session from 9.15am, followed by a talk in the main Adventure Auditorium at 10am. Tickets to the show cost £8 in advance, or £10 on the door.
7/8 Surf 'n' stretch
8. Surf 'n' stretch
Soul and Surf will run a one-off retreat from 23-30 March in Banda Aceh on Sumatra, Indonesia. There are 16 places on the one-week retreat, which includes sessions with a "surf guide" and yoga lessons. From £430pp excluding flights.
8/8 Make tracks
1. Make tracks
Ramblers Festival of Winter Walks takes place from 20 December to 4 January, with hundreds of free, guided walks across the country. Options include a Pre-Christmas Constitutional in Whitby and a Seven Parks Walk in London. You can also download walks from the Ramblers Routes library.
Heathrow Airport said 38 flights had been cancelled before 9.30am today and warned that there would still be logistical problems.
In a statement, a spokesperson said: "Following yesterday's technical problem at the Nats air traffic control centre in Swanwick, operations have started up well at Heathrow on what is a very busy day.
"There will, though, be cancellations to some flights because aircraft and crew are out of position.
"Passengers due to depart today should check the status of their flight with their airline before travelling to Heathrow. We are very sorry for the disruption to passengers' journeys."
Gatwick Airport suffered from 16 cancellations and seven diversions of inbound flights yesterday. It reportedly is running smoothly today, however.
"We don't expect to see any further significant disruption to our flights, for the remainder of the day,” a spokesperson for the airport confirmed.Reuse content