30 August, 2023

A single flight plan caused the Nats air traffic disruption?

According to National Air Traffic Services chief executive Martin Rolfe, the mass disruption to the UK's air traffic control over the bank holiday weekend was caused by a single piece of incoming flight data, namely a flight plan that halted the system.

Nats indicate that the flight planning system and its backup system are designed to effectively turn off when it doesn't recognise the data on an electronically filed flight plan. Supposedly, this is so air traffic controllers don't get erroneous information. This then meant that flight plans had to be processed manually which cannot be done at the same volume, therefore Nats had to introduce traffic flow restrictions.  

Nats says "Our priority is always to ensure that every flight in the UK remains safe and we are sincerely sorry for the disruption."

Thousands and thousands of passengers both in the UK and overseas had flights delayed or cancelled, disrupting travel arrangements on one of the busiest days of the year. The air traffic delays caused knock-on effects for many airlines, where aircraft and crews were in the wrong place and at the wrong time. 

“NATS exists to allow everyone flying in UK airspace to do so safely. Our systems enable our air traffic controllers to deliver this service all year round. These have several levels of backup and allow us to manage around 2 million flights per year in some of the busiest and most complex airspace in the world safely and efficiently." said Rolfe. 

International Air Transport Association boss Willie Walsh said there were huge questions to answer and the failure unacceptable".  The former boos of IAG also stated whilst airlines would "bear significant sums in care and assistance charges, on top of the costs of disruption to crew and aircraft schedules. But it will cost Nats nothing."

Ryanair said it had been forced to cancel about 250 flights on Monday, disrupting around 40,000 passengers, while on Tuesday 70 flights were cancelled and normal operations resumed on Wednesday.

Philip Hinton, SVP, of IBS Software told us: “The UK air traffic control failure puts airlines’ abilities to handle disruption under the spotlight. Airlines are now under real pressure to rebook passengers and cope with the knock-on impact of a major disruption to future flights. That’s not a simple task, made harder by the fact too many airlines rely on legacy IT systems that can exacerbate delays. Disruption to operations is a daily challenge for airlines but without a modern system that can instantly provide them with quick solutions to complex operational challenges and the insight needed to communicate clearly with passengers, airlines are risking their relationship with customers. In the UK, over half of travellers experiencing delays struggle to find out why their plans have been thrown into turmoil and one-quarter say bad disruption this summer will prompt them to reconsider the airline they use.”

 Rolfe said: “We have well-established procedures, overseen by the CAA, to investigate incidents. We are already working closely with them to provide a preliminary report to the Secretary of State for Transport on Monday. The conclusions of this report will be made public.

I would like again to apologise to everyone who has been affected.”

Of course, Nats has said there is no evidence of a cyber attack, whilst internet rumours seem to say it was a dodgy flight plan filed by a specific French airline and other cyber-security experts are said to be analysing a massive spike in attacks over the weekend. Nats says the report into the incident will be made public in due course, but they didn't make it public the last time one of their systems was hacked by a foreign state-sponsored actor, according to a senior air traffic controller located in Swanwick, so maybe we'll never know what really caused the issue.