UK air traffic control fault fixed after NATS Prestwick outage: delays may continue

Last verified: 21 September 2026. The air traffic control fault that disrupted flights across Scotland, Northern Ireland and northern England on Monday has been fixed, according to NATS. However, airlines and airports may continue to experience knock-on delays while traffic restrictions are removed and schedules recover. If you are flying today, check your airline’s live status before leaving for the airport.

What happened at NATS Prestwick?

NATS said its Prestwick control centre in Scotland experienced a technical problem early on Monday 21 September. The organisation applied air traffic regulations to reduce demand while engineers investigated the fault.

NATS later confirmed that the problem was a connectivity issue affecting part of its systems network in Scotland. It said the fault had been fixed and that it was working with airports and airlines to lift the remaining restrictions safely.

The incident was separate from the major NATS disruption earlier in September. NATS explicitly said the Prestwick problem was not connected to that earlier failure.

Which UK flights were affected?

The main disruption was concentrated in Scotland, Northern Ireland and northern England. Manchester, Glasgow and Belfast were among the airports reporting delays, while Edinburgh also experienced disruption. Some flights elsewhere in the UK were affected through aircraft and crew being out of position or through services travelling into the affected airspace.

Reuters reported that Ryanair said more than 25,000 of its passengers and more than 140 flights had been affected during the day. Those figures are a snapshot rather than a live total, so travellers should use their airline or airport app for the latest status of an individual flight.

Is the air traffic control problem still active?

No. NATS says the technical fault itself has been fixed. The important distinction is that a repaired air traffic control system does not instantly restore every airline schedule. Delayed aircraft, displaced crews and earlier airspace restrictions can continue to create disruption after the underlying problem is resolved.

NATS is therefore advising passengers to keep checking directly with their airline.

What should passengers do now?

• Check your airline’s live flight status before travelling to the airport.
• If your flight is cancelled, follow the airline’s instructions rather than travelling to the airport unnecessarily.
• Keep receipts for reasonable food, drink or accommodation costs if your airline cannot provide required care directly.
• If you are connecting through a UK airport, check every sector of the booking because knock-on delays can affect an onward flight even when the departure airport itself was not at the centre of the outage.

What are your rights if your flight is cancelled or badly delayed?

Where UK261 passenger-rights rules apply, airlines still have obligations during disruption. The UK Civil Aviation Authority says passengers whose flight is cancelled should normally be offered a choice between a refund and re-routing. Airlines may also have to provide food, drink and accommodation during qualifying delays.

Fixed-sum compensation is different. The CAA says compensation is not payable when disruption results from qualifying “extraordinary circumstances” outside the airline’s control. On 21 September, the CAA said disruption directly caused by the Prestwick technical issue, and some directly caused knock-on disruption, is likely to count as an “extraordinary circumstance”. Passengers are therefore unlikely to be entitled to fixed-sum UK261 compensation for those delays or cancellations, although each case remains fact-specific. Airlines must still provide care and assistance, and cancelled passengers must be offered a refund or re-routing; where the airline cannot provide suitable care or replacement travel, the CAA says reasonable self-arranged costs should be reimbursed. Each case remains fact-specific, so passengers should not assume either that compensation is guaranteed or that no claim is possible.

Official information

• NATS: Technical issue at Prestwick Centre, 21 September 2026
• UK Civil Aviation Authority: flight delay rights
• UK Civil Aviation Authority: compensation guidance following the 21 September NATS disruption

This article will be updated if NATS, airports or airlines announce a material change to the disruption.