The Ministry of Defence has denied making errors after claims the air traffic control meltdown was caused by a military plane entering ‘spurious’ flight data into the system.
Some 2,000 flights were cancelled after a four-hour technical failure at National Air Traffic Services (NATS) last Tuesday, affecting more than 330,000 travellers.
Sources claimed NATS operations director Kathryn Leahy told industry bosses that evening that a flight plan submitted by a UK military aircraft triggered the outage.
The entry was said to have caused a glitch within the wider air traffic control system that took hours to restart, according to four insiders speaking to the Financial Times.
But the Ministry of Defence has now hit back, saying in a statement: ‘We do not believe there’s any indication of an error on the part of the military.
‘Because it’s subject to a live NATS investigation, which is expected to conclude [this] week, it would be inappropriate for us to comment any further while that investigation is ongoing.’
A NATS spokesman added: ‘The problem was fixed on Tuesday, and we are continuing to investigate the underlying cause. It would be wrong to speculate while that work continues, and a full technical investigation will follow.’
The disruption has prompted calls for NATS chief executive Martin Rolfe to resign – with Ryanair boss Michael O’Leary calling his position ‘untenable’.
The National Air Traffic Services air traffic control centre in Swanwick, Hampshire (file image)
NATS chief executive Martin Rolfe has faced calls to resign after the technical failure
Wizz Air has also said Mr Rolfe should go, saying it was ‘extremely disappointed’ by the technical failure and that NATS is ‘simply not fit for purpose in its current form’.
Transport Secretary Heidi Alexander told MPs that she did not believe the air traffic control issue was ‘unavoidable’.
Mr Rolfe was hauled in for a meeting with her last Wednesday and was given a week to produce a report on the cause behind the fault.
Ms Alexander has said this must ‘be on my desk’ by this Wednesday. She has so far refused to back Mr Rolfe, but has also declined to say he must resign.
Ms Alexander has also asked Civil Aviation Authority (CAA) chief executive Rob Bishton for an independent review within six months.
Mr Rolfe has received £2.2million in bonuses and incentive payments over the past three years despite two high-profile air traffic control failures in 2023 and 2025.
Some 2,145 flights were affected across Tuesday and Wednesday last week following the IT meltdown.
Last July, a ‘radar-related issue’ caused an air traffic control failure which disrupted thousands of passengers and forced the cancellation of more than 160 flights.
Passengers wait at London Heathrow Airport last Tuesday amid widespread flight delays
And more than 700,000 passengers suffered disruption in August 2023 when flights were grounded after NATS suffered a technical glitch while processing a flight plan.
The CAA has said passengers are ‘unlikely to be entitled to compensation for delays or cancellations that were directly caused by the incident’, because the outage is likely to be considered the result of ‘extraordinary circumstances’.
The flight disruption has since eased as airports including Heathrow, Gatwick, Luton and Stansted confirmed last Thursday that their operations had returned to normal.
Meanwhile Labour was ridiculed after it emerged that its aviation minister had boasted about giving the air traffic control system ‘increased resilience’ just a day before the system collapse.
In response to a written parliamentary question last Monday, Keir Mather said the system was ‘well prepared’ after ministers introduced laws in a bid to prevent a repeat of a malfunction in 2023.
Tory MP Richard Holden said: ‘Labour ministers can’t have it both ways: if they boast about systems they created when they’re working, they should take responsibility when they fail.’
NATS – which is based in Swanwick, Hampshire – is a public-private partnership, with the government holding the controlling stake.
The rest is split between a group of UK airlines including British Airways, easyJet and Virgin Atlantic as well as Heathrow and NATS staff.
