Air traffic chaos last summer caused by engineers working from home

Air traffic control chaos which delayed more than 700,000 passengers was caused by a ‘lack of planning’ and engineers working from home, an investigation has found.

Hundreds of flights were cancelled and thousands of people were left stranded abroad after a major fault in the air traffic control (ATC) system on August 28 last year – a bank holiday Monday and one of the busiest days of the year for air travel.

Air traffic control provider National Air Traffic Services (Nats) suffered a technical glitch while processing a flight plan.

The consequences were huge, with airlines losing around £100 million in refunds, rebookings, hotel rooms and refreshments.

An interim report from the Civil Aviation Authority (CAA) found more than 300,000 people suffered cancellations, 95,000 endured delays of over three hours, and at least a further 300,000 faced shorter delays.

The inquiry panel found there had been no ‘multi-agency rehearsal of the management of an incident of this nature and scale’ – even though this sort of preparation and planning happens regularly in other sectors.

The report said there was ‘a significant lack of pre-planning and co-ordination for major events and incidents’ focusing on how to put things right.

Nats wouldn’t usually schedule planned maintenance work on public holidays, so engineering staff would ‘be available on standby at remote locations – typically at home’.

It took 90 minutes for a Level 2 on-call engineer to get there and carry out a full system restart which couldn’t be done from home, but no one called for a more senior engineer ‘for more than three hours after the initial failure’.

The flight plan in question listed two waypoints, or locations, with the same abbreviations, causing the system to generate a ‘critical exception error’ and shut down to ‘prevent the transfer of apparently corrupt flight data to the air traffic controllers’, the report said.

Tim Alderslade, chief executive of Airlines UK, which represents UK-registered carriers, said the report contains ‘damning evidence that Nats’ basic resilience planning and procedures were wholly inadequate and fell well below the standard that should be expected for national infrastructure of this importance’.

A Nats spokesman said it had already been working on improvements.

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