Around 200 flights to and from UK airports were cancelled on 21 September after a "connectivity issue" hit NATS's Prestwick centre — the second air-traffic-control failure to disrupt the country's network inside a fortnight. Aviation analytics company Cirium put the figure at roughly 100 inbound and 99 outbound cancellations as of 13:45 BST, with easyJet absorbing the heaviest load: 47 of its 670 scheduled departures, or about 7%. British Airways recorded 11 cancellations out of 513 scheduled departures.

What the network looks like

The damage clustered in northern airspace. A NATS spokesperson said its Prestwick centre in Ayrshire, Scotland, identified the fault "early this morning" and reported the system "fixed" and running at "full capacity" by early afternoon. NATS said airports "south of Manchester" were "broadly unaffected", though cancellations reached Glasgow, Edinburgh, Belfast International, Birmingham and City of Derry on routes to London Stansted, London Heathrow, Liverpool, Newcastle and Edinburgh itself. NATS said its remaining task is "working with our customers to recover their residual delays and help get their operations back to normal".

What operators are demanding

Ryanair chief operating officer Neal McMahon said NATS chief executive Martin Rolfe "should resign today", accusing him of failing to deliver "either a reliable system or an effective back-up". Jet2 chief executive Steve Heapy demanded "urgent and accountable" action, asked "how many more failures do customers and airlines have to deal with?" and confirmed the carrier would "be sending another bill to NATS". Wizz Air UK managing director Yvonne Moynihan called the episode a "national confidence crisis" and pressed for "urgent reform". Speaking to BBC Radio 4's World At One, Moynihan said: "If this is just a millisecond glitch, why did it take down an entire traffic system?" and added: "I don't have the confidence to be honest" in NATS governance. EasyJet said the disruption "once again calls into question the resilience of NATS' systems" and called for "firm actions".

How this one compares to 8 September

NATS moved quickly to separate the two events, telling reporters the new outage had "nothing to do" with the 8 September software defect inside the National Airspace System that led to roughly 2,000 cancellations. Airlines UK chief executive Tim Alderslade struck a more sceptical note, saying passengers and carriers "deserve better" and calling on Parliament's upcoming civil aviation bill to "address the underlying weaknesses in the system". Abta's Luke Petherbridge characterised the latest failure as "the second NATS incident to cause disruption in the last fortnight, and fourth in recent years", and asked the government to "seriously consider" whether NATS should financially compensate the "wider industry".

What it costs airlines

Transport Secretary Heidi Alexander confirmed the issue had been "fixed" but acknowledged the disruption would be "deeply frustrating" for passengers. The UK Civil Aviation Authority moved to manage traveller expectations, ruling the incident "likely to be considered the result of 'extraordinary circumstances' under passenger rights rules" and concluding affected travellers are "unlikely to be entitled to compensation". Rerouting and care duties still fall on carriers, however — a position that strips passengers of their usual commercial lever but does not protect airlines from utilisation losses, crew-positioning costs and the reciprocal-billing dispute Jet2 signalled it intends to pursue. NATS itself acknowledged the broader point: in a statement a spokesperson said "In the real world we accept technology can and sometimes does fail", adding that safety remains "always our first priority".

What now

The political temperature will rise when Alexander, Rolfe and the operators reconvene around the civil aviation bill and any inquiry into the 8 September failure, with carrier demands for an accountable, investable NATS backbone now placed firmly on the legislative agenda.