Nats software fault grounds UK flights

What's happened

National Air Traffic Services has identified a fault in its flight-processing system and has implemented a fix after pausing some departures on Tuesday. The outage has caused widespread cancellations and delays at Heathrow, Gatwick, Manchester, Birmingham and Scottish airports; recovery is continuing and airlines are warning of knock-on disruption today, 15 Sep 2026.

What's behind the headline?

What happened and why it matters

• Nats has identified the fault in its flight processing system and has implemented a fix, but the organisation is still restoring normal operations. That is creating a backlog of aircraft and crews which will continue to disrupt schedules.

System fragility, not a one-off

• This will expose that critical software and contingency planning remain weak: industry filings and reporting show Nats has faced at least two major faults in recent years. Repeat failures will force airlines to demand stronger guarantees or regulatory oversight.

Immediate consequences

• Airlines will continue to cancel and delay services while crews and aircraft reposition. Passengers will face hotel and meal claims under EU/UK passenger-rights rules; airlines will push those costs back to Nats or classify the incident as an extraordinary circumstance.

Forecast

• The backlog will take at least 24–48 hours to clear fully. This will increase pressure on Nats' leadership and on regulators to publish a detailed root-cause report. Airlines will press for clearer contingency rules and compensation frameworks.

What to watch next

• A public investigation report from Nats, statements from major carriers on losses, and any regulatory action or required remediation timetable will determine whether the industry treats this as a systemic failure or an isolated technical error.

How we got here

Nats runs UK en-route and terminal air traffic services for 15 airports and handles millions of flights a year. The firm has suffered multiple technical failures in recent years, including a 2023 flight-plan collapse and a radar issue in 2025 that prompted regulatory scrutiny and large airline costs.

Our analysis

Reuters reported that Nats posted on X that engineers were on site, saying: "We are investigating a technical issue which is causing some disruption to flight departures." The Guardian quoted Nats' update and highlighted that departures from London airports were most severely affected, noting "Flights are still departing and airspace is open, but recovery will take some time." The Scotsman provided local detail on cancellations at Edinburgh, Glasgow and Aberdeen and quoted airport spokespeople advising passengers to check with airlines; Alastair Dalton noted almost 1,400 UK cancellations in one report while other Scotsman copy reported dozens of Scottish cancellations. CNBC carried Nats chief Martin Rolfe's remarks to BBC Radio 4: he said investigators have "ruled out cyber" and that the incident was different to previous failures; CNBC also reproduced airline criticism from Ryanair's Neal McMahon calling the failure "abhorrent." The Independent and AP supplied practical passenger-advice and rights guidance, with the Independent summarising EU/UK rules on care and compensation. Together the sources show a consistent narrative: Nats has fixed a software fault, airports and airlines are managing a growing backlog, and industry figures are sharply critical because this follows earlier high-profile failures.

Go deeper

• When will Nats publish a root-cause report and timeline for fixes?
• How will regulators and airlines demand stronger contingency plans or penalties?
• Who will pick up the immediate cost of passenger care and airline compensation?

More on these topics

• United Kingdom - Country in Europe

  The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom or Britain, is a sovereign country located off the north­western coast of the European mainland.

• London Heathrow Airport - Airport in England

  Heathrow Airport, originally called London Airport and now known as London Heathrow, is a major international airport in London, United Kingdom.

• NATS - Wikimedia disambiguation page

  Nats or NATS may refer to:

• Flightradar24 - Internet site

  Flightradar24 is a Swedish internet-based service that shows real-time commercial aircraft flight tracking information on a map.

• Edinburgh Airport - Airport in Scotland

  Edinburgh Airport is an airport located in the Ingliston area of Edinburgh, Scotland. It was the busiest airport in Scotland in 2019, handling over 14.7 million passengers.

• British Airways - Airline

  British Airways is the flag carrier airline of the United Kingdom, headquartered in London, England, near its main hub at Heathrow Airport. It is the second largest airline in the United Kingdom, based on fleet size and passengers carried, behind easyJet.

• Scotland - Country of the United Kingdom

  Scotland is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a 96 mile border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the north and w

• Manchester - City in England

  Manchester is a city and metropolitan borough in Greater Manchester, England. It has a population of 547,627 as of 2018. It lies within the United Kingdom's second-most populous urban area, with a population of 2.5 million and third-most populous metropol

• Birmingham - City in England

  Birmingham is a city and metropolitan borough in the West Midlands, England. It is the second-largest city, urban area and metropolitan area in England and the United Kingdom, with roughly 1.1 million inhabitants within the city area, 2.9 million inhabita

• Manchester Airport - International airport in Manchester, England

  Manchester Airport (IATA: MAN, ICAO: EGCC) is an international airport in Ringway, Manchester, England; it lies 7 miles (11 km) south-west of Manchester city centre. In 2024, it was the third-busiest airport in the United Kingdom in terms of passengers...

• easyJet - Airline

  EasyJet plc, styled as easyJet, is a British low-cost airline group headquartered at London Luton Airport. It operates domestic and international scheduled services on over 1,000 routes in more than 30 countries via its affiliate airlines EasyJet UK, Easy

• London City Airport - Airport in London, England

  London City Airport is an international airport in London, England. It is located in the Royal Docks in the London Borough of Newham, approximately 7 miles east of the City of London and a shorter distance east of Canary Wharf.

• London Gatwick Airport - Airport in England

  Gatwick Airport, also known as London Gatwick, is a major international airport near Crawley, Sussex, England, 29.5 miles south of Central London. It is the second-busiest airport by total passenger traffic in the UK, after Heathrow Airport. Gatwick is th

• London Luton Airport - Airport in England

  London Luton Airport, previously called Luton International Airport, is an international airport located 1.5 miles east of Luton town centre in the county of Bedfordshire, England, and is 28 miles north of Central London.

• London - Capital and largest city of England and the United Kingdom

  London is the capital and largest city of both England and the United Kingdom, with a population of 9.1 million people in 2024. Its wider metropolitan area is the largest in Western Europe, with a population of 15.1 million. London stands on the River...

• British Broadcasting Corporation - Broadcasting company

  The British Broadcasting Corporation is a British public service broadcaster. Headquartered at Broadcasting House in Westminster, London, it is the world's oldest national broadcaster, and the largest broadcaster in the world by number of employees.

• Aberdeen - City in Scotland

  Aberdeen is a city in northeast Scotland. It is Scotland's third most populous city, one of Scotland's 32 local government council areas and the United Kingdom's 39th most populous built-up area, with an official 2018 population estimate of 198,880 for th

• Lufthansa - Airline

  Deutsche Lufthansa AG, commonly known as Lufthansa, is the largest German airline which, when combined with its subsidiaries, is the second largest airline in Europe in terms of passengers carried.

• AGS Airports - Owner of Aberdeen, Glasgow and Southampton airports

  AGS Airports Limited is the owner of Aberdeen, Glasgow and Southampton airports. Based in Leeds, England, it was formed in September 2014 by Ferrovial and Macquarie Group. In January 2025 it was sold to AviAlliance.

• Ryanair - Airline

  Ryanair DAC is an Irish budget airline founded in 1984, headquartered in Swords, Dublin, with its primary operational bases at Dublin and London Stansted airports.

• Wizz Air - Airline

  Wizz Air, legally incorporated as Wizz Air Hungary Ltd. and stylised as W!ZZ Air, is a Hungarian ultra low-cost airline with its head office in Budapest.

• Glasgow - City in Scotland

  Glasgow is the most populous city in Scotland, and the third most populous city in the United Kingdom, as of the 2019 estimated city population of 611,748.