Claim: A foreign power launched a cyber-attack.
Reality: This was the most dramatic theory, but officials have firmly ruled it out. Martin Rolfe, the chief executive of National Air Traffic Services (NATS), stated that they had ruled out cyber activity and do not believe it was a cyber-attack. The
Transport Secretary also told lawmakers that a cyber-attack was "categorically" not the cause. The problem was a technical fault within the flight data processing system, the software that turns filed flight plans into information controllers can use. While the exact cause is still under a formal investigation by both NATS and the Civil Aviation Authority (CAA), all official communication has pointed to an internal technical failure, not external malice.
Claim: The entire air traffic control system is ancient and collapsed.
Reality: While the failure was significant, it was a specific component that failed, not the entire infrastructure. The problem occurred in the flight-plan processing system. For safety, when this automated system fails, controllers must revert to a manual process. This manual system is safe but much slower, drastically reducing the number of flights the sky can handle at any one time. This is what led to the grounding of planes and the massive backlog. NATS has defended the overall resilience of its systems, with the CEO stating he did not believe the incident showed the systems were unfit for purpose. However, this is the second major failure in three years, prompting intense scrutiny and calls for an overhaul of the system's resilience to prevent future chaos.
Claim: Only a few flights at Heathrow were affected.
Reality: The disruption was nationwide and affected all major UK airports, with a massive knock-on effect across Europe. In total, more than 2,000 flights were cancelled across Tuesday 8th and Wednesday 9th September. Aviation analytics firm Cirium reported that around 1,750 flights were cancelled on the first day alone, representing about 30% of the day's entire schedule. London's Heathrow and Gatwick airports were severely impacted, but so were Manchester, Stansted, and Birmingham. The chaos stranded hundreds of thousands of passengers and created a logistical nightmare for airlines, which had to reposition not just planes but also flight crews who were left in the wrong cities.
Claim: Everything was back to normal the next day.
Reality: While engineers fixed the technical fault within hours on the day of the incident, the knock-on effects lasted for several days. The sheer volume of cancelled flights meant aircraft and crew were out of position, and passenger backlogs were immense. Airlines had to work through the night to create new schedules, but hundreds of additional flights were still cancelled the following day. Heathrow warned of continued disruption as airlines worked to recover. Flight schedules were only expected to return to normal towards the end of the week, showing just how complex and interconnected the aviation network is.
Claim: Passengers will receive compensation from the airlines.
Reality: This is unlikely for most passengers affected directly by the outage. The Civil Aviation Authority (CAA) stated that the disruption is likely to be considered the result of 'extraordinary circumstances' under passenger rights rules. This term applies to situations outside of an airline's control. Because the fault lay with the national air traffic infrastructure and not the airlines themselves, carriers are not legally required to pay compensation for the cancellation or delay. They are, however, still obligated to provide care, such as meals, communication, and accommodation if necessary, or offer a refund or an alternative flight.
