All Departures Grounded at Heathrow, Triggering Major Travel Disruption

Heathrow halted every departing flight at 12:48 p.m. BST on Tuesday, September 8, 2026, after a technical failure hit UK air traffic control systems. Within minutes the same fault stopped departures at airports across the UK — confirming this was a national air traffic control problem, not a Heathrow equipment fault. Around 15 airports were ultimately affected.

NATS, the company that runs UK air traffic control, confirmed the failure at 13:46 BST, an hour after departures first stopped.

“We are investigating a technical issue which is causing some disruption to flight departures. Our engineers are on site and we will provide an update as soon as we can.”

NATS statement, 13:46 BST, September 8, 2026

An hour and a half later, NATS named the failed system.

“We have identified that the issue was in our flight processing system. Our engineers are on site and working urgently to resume normal operations as quickly as possible.”

NATS statement, 15:25 BST, September 8, 2026

NATS added that “flights are still departing and airspace is open, but recovery will take some time,” and apologised for the disruption. Heathrow departures restarted after the lunchtime pause but passengers continued to face stop-start delays through the afternoon. Arrivals were never stopped by the fault.

At 16:40 BST, nearly four hours after departures first stopped, NATS said a fix was in.

“We have implemented a fix and our flight system is starting to recover. We are continuing to work closely with our airline and airport customers on recovery.”

NATS statement, 16:40 BST, September 8, 2026

A fix is not the same as a cleared backlog. “Starting to recover” describes the system, not the schedule, and the flights already cancelled do not come back. NATS has still not declared normal operations restored.

The phrase “some disruption” understates what passengers saw. Ground radar over Heathrow through the early afternoon showed more than 50 aircraft stationary at once — jets parked on stands, backed up along both parallel taxiways and queued at the runway holding points with nowhere to go. Passengers at Gatwick and Heathrow reported being held on board aircraft that had already pushed back.

Timeline: how September 8 unfolded

All times are British Summer Time (BST), which is UTC+1. Heathrow had already lost capacity that morning before the air traffic control fault landed on top of it.

Ports of Jersey confirmed the reach of the fault beyond London, saying UK air traffic control problems were “impacting flights across the UK including services between Jersey and UK.” Passengers at Gatwick were told to check in as normal but to confirm status with their airline before travelling.

The failure limited NATS’ ability to process automated outbound flight data across roughly 15 UK airports. Those reported affected include:

The geographic spread is itself evidence of the cause. A fault that reaches Aberdeen, Bristol and Jersey at the same moment is not an airport problem — it is a single national system that every one of those departure boards depends on.

Why arrivals kept landing while departures stopped

The most diagnostic detail of the day is the asymmetry. Aircraft already airborne continued to land normally at Heathrow and Gatwick while nothing could leave. That pattern points away from a runway obstruction, a power cut or a Heathrow-side equipment fault, all of which would have stopped arrivals too.

Departure and arrival traffic are handled by different parts of the air traffic system. An aircraft already in the air has a filed route, an assigned squawk and a controller working it — it can be brought down manually if needed. A departing aircraft, by contrast, needs a validated flight plan, a departure slot and a clearance issued through the systems that co-ordinate outbound traffic across the whole London control area. When that side of the chain fails, controllers cannot safely release new aircraft into the airspace, so the only safe action is to hold everything on the ground.

That is why the disruption appeared simultaneously at four airports hundreds of miles apart. NATS has not identified the failed system, and until it does, the specific cause remains unconfirmed.

How much traffic a Heathrow ground stop holds

Heathrow runs roughly 1,300 aircraft movements a day against a legal cap of 480,000 movements a year — a level of utilisation that leaves almost no slack in the schedule. About half of those movements are departures, spread across roughly 17 operating hours. That averages close to 40 departures an hour, and more than that in the midday and early-evening banks when long-haul flights push back together.

Heathrow handled 40 million passengers in the first half of 2026 and 47.85 million between January and July, and recorded its busiest single day of the year in July at 267,000 passengers. On an ordinary September Tuesday the airport moves in the region of 230,000 people. A two-hour departure stop therefore strands roughly 80 aircraft-loads of passengers before the recovery even begins.

The toll so far

Around 200 flights had been cancelled across the UK by early evening, and by 18:40 BST Heathrow alone accounted for roughly 100 cancellations and 367 delays against a daily average near 1,300 movements. Gatwick had about 250 delays, close to a third of its operations. The worst affected were Heathrow, Gatwick, Manchester and Birmingham, with Stansted, Southend, London City, Isle of Man and Jersey also hit. Flights in and out of Dublin were delayed as the disruption spread beyond UK airspace.

By the end of the day Flightradar24 put the total at about 425 cancelled flights to and from UK airports, with more than 400 already cancelled by 17:00 and roughly 90 of those at Heathrow and Gatwick by 16:15. Earlier figures in this article were live counts taken while the recovery was still running, and different trackers reported different numbers at different moments. Airlines and airports typically publish confirmed totals the following morning, and the number of cancellations usually rises as carriers cut the evening schedule to reset aircraft and crews for the next day.

What the government and the airlines have said

Transport Secretary Heidi Alexander said engineers were “fixing it as we speak” and apologised to passengers.

“I know this will be frustrating for passengers and I’m sorry.”

Heidi Alexander, Transport Secretary

British Airways, the largest operator at Heathrow, said the disruption was “entirely out of our control” and that its teams were working to get customers “on their way as quickly as possible.” easyJet said the fault was causing knock-on delays across Europe.

By evening the tone had hardened. Ryanair cancelled more than 50 flights, said over 65,000 of its passengers were delayed, and called for the resignation of NATS chief executive Martin Rolfe — the same demand it made after the July 2025 outage.

“A critical national infrastructure provider should not repeatedly bring the aviation system to a standstill.”

Wizz Air

NATS apologised “sincerely for the disruption to people’s journeys today.” The word carrying the weight in both airline statements is repeatedly: this is the fourth major failure since 2014 and the second of the same type since 2023, and that pattern is what will drive any regulatory response.

That phrase from British Airways is worth reading carefully, because it is legally loaded. “Entirely out of our control” is the language of the extraordinary-circumstances defence, and it is almost certainly correct here. It removes your right to cash compensation. It does not touch the duty of care set out below, and no airline statement can.

Why the delays outlast the fault by many hours

When NATS restores the system, flights do not simply resume where they left off. Four separate constraints stretch a short outage across the rest of the day, and they are the reason a two-hour fault routinely produces a full evening of cancellations.

This is the mechanism that turned a 20-minute Swanwick fault in July 2025 into more than 100 cancellations, and a single rejected flight plan in August 2023 into four days of disruption.

The fourth major NATS failure in twelve years

Tuesday’s outage is not an isolated event. UK air traffic control has suffered four significant technical failures since 2014, and each one had a different root cause.

Note what the 2026 and 2023 entries have in common. Both were failures of flight plan processing — the system that turns a filed route into something controllers can safely release into the airspace. That is the same class of system failing twice in three years, and it is the question NATS will be asked first.

The 2023 failure produced a formal Major Incident Investigation report for the Civil Aviation Authority. After the July 2025 outage, the Transport Secretary demanded answers from the NATS chief executive and Ryanair publicly called for his resignation. A fourth failure inside thirteen months will make that political scrutiny sharper still.

What to do right now if you are flying from a UK airport today

The single most common mistake during an ATC outage is abandoning a booking before the airline has cancelled it. Doing so converts a delay the airline owes you care for into a no-show it owes you nothing for.

1. Check your airline’s app or website, not the airport board. Airport boards lag airline systems by 15 to 30 minutes during a disruption. The airline is the only source that will actually rebook you.
2. Do not cancel the booking yourself. If you cancel, you lose your UK261 rights entirely. Wait for the airline to cancel or for the delay to cross the thresholds below.
3. Go to the airport unless your airline has told you not to. Airlines cannot re-route passengers who are not present, and a returning slot can be released at short notice.
4. Use the airline’s self-service rebooking before joining the queue. Disruption tools in the app usually open earlier and offer more seats than the desk.
5. Keep every receipt. Meals, taxis and hotel costs are reclaimable even when compensation is not. Photograph receipts as you go.
6. Screenshot the delay notice and the departure board. Written evidence of the cause and the timings is what wins a later claim.
7. Warn anyone meeting you or holding a connection. A separately booked onward ticket will not be protected — see the visa section below.

Your rights under UK261 when air traffic control fails

UK261 — the retained UK version of Regulation EC261 — governs flights departing any UK airport, and flights arriving in the UK on a UK or EU carrier. It splits into two very different entitlements, and the distinction matters enormously in an ATC failure.

Cash compensation: unlikely today

Compensation is payable only when the disruption was within the airline’s control. Air traffic control restrictions, airspace closures and ATC system failures are treated as extraordinary circumstances — outside the airline’s control — so a claim arising from today’s outage will almost certainly be refused. For reference, these are the amounts that would apply if an airline-caused delay hit the same thresholds:

Duty of care: applies in full, no matter the cause

This is the part airlines are least likely to volunteer and passengers are most likely to forget. The right to care is not affected by extraordinary circumstances. Once your delay passes the threshold for your flight’s distance, the airline must provide assistance whether or not it caused the problem.

Two further rights sit alongside care. If your flight is cancelled, the airline must offer you a choice between re-routing to your final destination at the earliest opportunity and a full refund, paid within seven days. And if a delay reaches five hours and you decide not to travel, you can abandon the journey and claim a refund of the unused portion.

Visa and immigration problems a missed flight can create

For most travellers a delay is an inconvenience. For anyone travelling on a time-limited immigration document, a single missed departure can create a problem that no refund will solve. These are the traps worth checking today.

Airside transit passengers can be trapped by an overnight delay

Passengers connecting through Heathrow on a Direct Airside Transit Visa are not permitted to pass through UK border control. If a delay forces an overnight stay, a terminal change requiring immigration clearance, or a re-route through a different London airport, that document does not cover it — you would need a Visitor in Transit visa (border control, leaving within 48 hours) or a Standard Visitor visa. Tell the airline you are an airside transit passenger before it rebooks you, because it will otherwise offer an itinerary you cannot legally take. Our Heathrow transit visa guide sets out which nationalities need which document.

A 90-day UK entry vignette expiring this week

If you hold a physical entry clearance vignette in your passport, it is valid for a 90-day travel window, and travel outside that window is not permitted regardless of the reason for the delay. A cancellation that pushes your arrival past the vignette’s expiry date means applying for a replacement, which costs £154, requires resubmitting biometrics, and issues a fresh 90-day window. Note that vignettes have been phased out for main Student applicants since July 15, 2025, and for visit visa applications made on or after February 25, 2026, which now receive an eVisa only.

Students on tight course and program start dates

September 8 sits in the middle of enrolment season. UK Student route holders should notify their institution’s international office immediately if arrival will slip past registration, because sponsors are required to report students who fail to enrol. Travellers holding a US F-1 visa cannot enter more than 30 days before the program start date on the I-20, and arriving after that date needs the designated school official’s sign-off or a deferred I-20 — arrange it before you rebook, not after you land.

Onward travel: what a UK delay does and does not cost you

Days spent stuck in the UK do not count toward the Schengen 90/180 allowance, because the UK is outside the Schengen Area. But a Schengen visa’s “valid until” date is the last day you may enter, not a grace period — a delay past it invalidates the trip. For US-bound passengers, an approved ESTA remains valid for two years and is not consumed by a missed flight, though it must still be valid on the new travel date, and admission is always decided by CBP at the port of entry. Anyone on a UK Skilled Worker route should tell their sponsor if the start date on the Certificate of Sponsorship will move.

Heathrow’s difficult week before the outage

Tuesday’s failure landed on an airport already absorbing a run of unrelated incidents. None of them caused the ATC fault, but together they explain why recovery capacity was thin.

Consumer group Which? raised the displacement problem after the September 4 Gatwick diversions, and its point applies equally today.

“If your flight was diverted as a result of the runway closure, your airline is responsible for ensuring you still reach the final destination on your ticket.”

Which?, on the September 4 Gatwick diversions

That obligation does not disappear when the cause is extraordinary. An airline that lands you at Stansted instead of Gatwick, or at Manchester instead of Heathrow, still owes you transport to the destination printed on your ticket.

What is still unconfirmed

Reporting during a live outage runs ahead of verified fact, and several widely shared claims about Tuesday do not yet have official support. As of 15:10 BST, the following remain open:

• What went wrong inside the flight processing system. NATS has named the system but not the failure mode. Claims circulating online that this was a power failure are not supported by any official statement.
• Whether the CAA opens a formal review. The 2023 outage produced a Major Incident Investigation report; nothing has been announced for this one.
• The final cancellation count. Flightradar24 put it near 425 on the day, but confirmed airline and airport totals typically follow the next morning and usually rise.
• Whether the backlog clears tonight. Crew duty limits and Heathrow’s 23:00 night quota will decide how much rolls into Wednesday.
• Heathrow’s 11:07 bird strike was a separate event. It suspended arrivals onto runway 27R independently of the ATC fault; the two should not be conflated.

Earlier reporting on this story, including a first version of this article, suggested live departure boards contradicted claims that Gatwick had been grounded. That reading was wrong: ITV News, Ports of Jersey and NATS have since confirmed departures were held at Gatwick, Southend and Jersey alongside Heathrow. Departure boards continued to list flights because held flights remain scheduled until an airline cancels them — a board showing departures is not evidence that aircraft are leaving.

Travellers on the busiest UK aviation corridor should plan for recovery to run into Wednesday. Comparable outages — including previous Heathrow and Gatwick disruption events — have consistently taken longer to clear than the fault itself lasted. This article will be updated as NATS publishes further statements.