Ryanair is demanding the resignation of NATS boss Martin Rolfe.
The airline’s call follows a recent technical failure that disrupted UK air traffic control overnight on July 6/7.
Around 30,000 Ryanair passengers faced delays of up to three hours on 155 flights after NATS (National Air Traffic Services) was unable to access vital weather data due to a technical issue.
Ryanair has accused NATS of repeatedly failing passengers and says Mr Rolfe should step down.
Your rights if your flight is cancelled or delayed
Neal McMahon, chief operations officer at Ryanair, said: "How many more system failures do passengers have to suffer before Martin Rolfe accepts responsibility and resigns?
"Nearly three years after NATS’ catastrophic 2023 system meltdown, UK passengers are once again being delayed because NATS’ systems have failed.
"Yesterday's outage delayed 155 Ryanair flights and disrupted almost 30,000 Ryanair passengers.
"Families travelling for holiday, people travelling for work and thousands of visitors to the UK have once again paid the price for NATS’ failure."
NATS says the most recent disruption was caused by a technical fault at the Met Office.
A spokesman for NATS said: "A Met Office technical issue overnight on July 6/7 meant that we weren't receiving vital weather information into our NATS systems for a short period of time.
"Accurate weather information is vital for air traffic controllers and pilots in managing flights safely.
"As a result, some air traffic restrictions were put in place and removed soon after.
"We continue to work with the Met Office who are working to fully resolve the problem."
Ryanair claims the incident shows that NATS has not addressed underlying problems since a major system collapse on August 28, 2023, which resulted in widespread cancellations and days-long delays for some passengers.
An independent review identified serious shortcomings in resilience, governance and incident management.
Mr McMahon said: "This is no longer an isolated incident; it's a pattern of repeated failure with Rolfe in charge.
"Martin Rolfe has presided over the 2023 system collapse, repeated staffing shortages, worsening delays and now yet another major system failure.
"It's time for new leadership at NATS.
"UK passengers deserve better. Airlines deserve better. NATS’ staff deserve better.
"The UK Govt, the CAA and NATS Board must stop accepting excuses and get someone capable in to run this critical piece of UK infrastructure."
NATS continues to work with the Met Office.
The Met Office has been contacted for comment.
Share