In-depth: CAA launches independent review into NATS outage as airports call for stronger resilience

The UK Civil Aviation Authority (CAA) has announced the terms of reference for its independent review into the NATS technical incident that disrupted UK air traffic services on 8 September 2026, as airports call for urgent action to strengthen the resilience of one of the country’s most critical transport systems.

Announced on 25 September, the review follows a request from Transport Secretary Heidi Alexander after the outage triggered widespread disruption across the UK aviation network. More than 2,000 flights were delayed, cancelled or diverted, affecting passengers, airlines and airports nationwide.

The review’s terms of reference, published by the CAA, will examine the causes of the incident, its impact on consumers and what additional measures may be required to improve confidence in the resilience of the UK’s air traffic management system.

According to a preliminary NATS report published on 18 September, the disruption was caused by a software defect. The CAA’s investigation will now assess both the immediate causes of the failure and wider questions surrounding system reliability, contingency planning and long-term modernisation of the UK’s air traffic control infrastructure.

A key area of focus will be NATS’ strategy for renewing, replacing and modernising operational systems. The regulator will examine whether existing business continuity arrangements remain fit for purpose, how effectively previous review recommendations have been implemented, and whether the CAA’s own oversight arrangements are sufficiently robust.

The review will also consider lessons from international best practice, particularly regarding resilience planning and the recovery of aviation systems following major operational disruptions. In addition to the 8 September outage, investigators are expected to examine other recent events, including further disruption experienced on 21 September.

To support the process, an independent challenge panel will be appointed by the CAA and approved by the Secretary of State. The panel will provide expert scrutiny and advice throughout the review, while the CAA team will engage with airlines, airports, passenger groups, NATS and other industry stakeholders.

An initial report is scheduled to be delivered to government by the end of January 2027, with a final report due by 8 March 2027.

The announcement has been welcomed by AirportsUK, which said the review must deliver meaningful improvements to system resilience in order to protect passengers, businesses and the wider economy.

Commenting on the publication of the review’s terms of reference, Karen Dee, Chief Executive of AirportsUK, said: “We welcome the Government’s decision to conduct a review to ensure that resilience to withstand future disruptions is built into our air traffic systems, so that passengers and businesses can have confidence in their ability to fly.”

She added that safeguarding the reliability of air traffic services was essential to maintaining the UK’s competitiveness.

“An increasing risk of disruption would result in the UK becoming less attractive as a place to visit, invest, and trade with, impacting the whole economy at a time when we need to be delivering growth,” Dee said.

The AirportsUK Chief Executive also stressed the importance of industry collaboration during the review process, saying the organisation looked forward to working with government, the CAA and NATS to ensure the review produces “a strong deliverable plan to protect this critical piece of national infrastructure”.

The review comes amid growing industry attention on the resilience of increasingly complex air traffic management systems. As passenger demand continues to recover and airspace modernisation programmes advance across Europe, aviation stakeholders are placing greater emphasis on ensuring that critical digital infrastructure can withstand technical failures without causing widespread operational disruption.

For airports, the consequences of air traffic system outages extend well beyond delays in the air. Terminal congestion, aircraft stand shortages, baggage processing challenges and passenger welfare issues can quickly escalate when flights are unable to depart or arrive according to schedule. As a result, many in the sector will view the CAA review as an important opportunity to assess not only technical systems but also the wider resilience of the aviation ecosystem.

The findings are expected to shape future discussions around investment, regulatory oversight and operational contingency planning, with the ultimate objective of ensuring the UK’s air traffic management network remains capable of supporting safe, reliable and efficient aviation operations in the years ahead.