The August bank holiday airport system outage which left 700,000 passengers stranded was a “major failure” while engineers worked from home, an equiry has revealed.
A Civil Aviation Authority inquiry found IT support engineers were permitted to work from home on the August bank holiday, one of the busiest days of the year.
A flight-plan glitch caused the National Air Traffic Services (NATS) computer system to collapse on August 28, meaning planes were unable to take off and land across the UK, costing cost airlines £100 million in compensation pay-outs.
The inquiry today called for senior engineers to be on duty in the NATS offices at all times to prevent it happening again.
Inquiry chairman Jeff Halliwell named the event a “major failure” on the part of the air traffic control system.
He said: “Our report sets out a number of recommendations aimed at improving NATS’ operations and, even more importantly, ways in which the aviation sector as a whole should work together more closely to ensure that, if something like this does ever happen again, passengers are better looked after.
“It caused considerable distress to over 700,000 passengers and resulted in substantial costs to airlines and airports.”
Flights had to be manually processed causing significant delays, decreasing the rate from up to 800 per hour to 60 per hour.
After the glitch the engineer couldn’t log in remotely, and since engineers were working from home, it took an hour and a half to reach the airport before performing a full system restart.
It didn’t resolve the issue, and four hours after the incident was first flagged, a call was made to the system’s German manufacturer, Frequentis Comsoft.
Rob Bishton, chief executive of the Civil Aviation Authority, added: “It is vital that we learn the lessons from any major incident such as this.”
The inquiry found the NATS system crashed while processing a flight plan from Los Angeles to Paris due to two waypoints – Devil’s Lake (North Dakota) and Deauville (France) – sharing the same three-letter code.
The system became confused when the plan suggested the flight would leave UK airspace into Deauville before arriving, and within 20 seconds, both the main processor and its backup crashed.
The system had previously processed more than 15 million flight plans without this scenario being seen.
A Nats spokesman said it has fixed the issue that caused the problem: “We would like to apologise again for the inconvenience passengers suffered because of this very unusual technical incident.
“Over the 15 months since this incident, we have worked hard to address the lessons from it, and to ensure it cannot ever happen again.
“We will study the independent review report very carefully for any recommendations we have not already addressed and will support their industry-wide recommendations.”
