An air traffic control system outage that disrupted more than 300,000 travelers was “one in 15 million” events, experts say

A computer failure in “one in 15 million” in Britain’s air traffic control system was responsible for the collapse of Britain’s bank holiday operations.

As it turns out, a software update is due this week to prevent the chaos from repeating itself.

The National Air Traffic Services (NATS) system outage caused the cancellation of more than 2,000 flights and disrupted the travel plans of more than 300,000 people.

Families around the world were stranded, many forced to sleep on airport floors and paying huge bills of thousands of pounds to find accommodation and alternative routes home.

At the time of the crisis, two teams of NATS computer engineers, one on-site at Swanwick Air Traffic Control Centre, Hampshire, and a second team working remotely, were unable to troubleshoot the issue.

A computer failure in “one in 15 million” in Britain’s air traffic control system was responsible for the collapse of Britain’s bank holiday operations. Pictured: Passengers waiting at Stansted Airport August 29 after flights were delayed

As it turns out, a software update is due this week to prevent the chaos from repeating itself. The system failure at National Air Traffic Services caused the cancellation of more than 2,000 flights and disrupted the travel plans of more than 300,000 people. Pictured: travelers whose flights were canceled/delayed at Stansted Airport last month

The problem could only be solved after contacting a technical design team and the manufacturer of the computer system.

Details were revealed in a report by NATS sent to Transport Secretary Mark Harper and the Civil Aviation Authority (CAA).

The CAA is today launching an independent investigation into what it calls an “unlikely data anomaly” that is expected to last three months.

An initial investigation by NATS indicates a software error related to the flight plan of a single long-haul flight through UK airspace.

The flight was due to depart at 4am on Bank Holiday Monday and then fly over the UK before landing at its destination at 3pm the same day.

A problem in identifying entry and exit points through UK airspace resulted in both the main computer system and its backup going into “critical exceptional mode” and effectively inoperable “to ensure safety”.

As a result, air traffic controllers had to manually log planes coming and going, dramatically reducing the number of flights that could be handled.

Willie Walsh, former BA chief and chief executive of international airline IATA, estimates the cost to airlines of cleaning up the mess, including paying refunds and covering passenger expenses, could amount to as much as £100m .

He has called for a change in the compensation system to hold NATS responsible for any losses caused by his failures.

The airline and flight plan details related to the computer failure were not disclosed, but there are indications it was a transatlantic flight between North America and France.

According to CAA sources, the details of the flight are not relevant as “a correct flight plan was entered” and it was purely a “downstream systems issue”.

The NATS investigation says the problem arose for the first time in the five years that the computer system has been in operation, handling more than 15 million flights. A person familiar with the investigation said it was a “one in 15 million” event. Pictured: Disturbed travelers at Stansted Airport on August 29

The NATS investigation says the problem arose for the first time in the five years that the computer system has been in operation, handling more than 15 million flights. A person familiar with the study said it was therefore a “one in 15 million” event.

NATS said an upcoming system software change should prevent a recurrence.

It stated: “A permanent software change by the manufacturer … will prevent the critical exception from reoccurring for any flight plan that triggers the conditions that led to the incident.” As to whether NATS should pay for the disruption, it said: “It is not within the competence of NATS to deal with further issues arising from the incident, such as reimbursement and compensation for the related disruption.” There is no evidence of cyber attacks and the CAA is convinced that there was no risk to the safety of passengers.

It states: “This technical event is now understood and should it recur, it would be remedied quickly and without impact on the aviation system.”

“Once testing is complete and the change process is evaluated, the plan is for the manufacturer to implement a software customization this week. This means it will not happen again.”