Airlines trade association boss <a href="https://www.thenationalnews.com/world/uk-news/2021/07/14/air-industry-chief-willie-walsh-attacks-unfair-vaccine-passports/" target="_blank">Willie Walsh</a> has railed against the unfair system that forces airlines to foot huge bills for issues that are out of their control as he estimated the cost of this week’s meltdown in air traffic control to be “close to £100 million” ($126.5 million). The director general of the International Air Transport Association (IATA) said members faced with huge bills are left “frustrated and angry” by rules that make it almost impossible for them to claim back the money. He said the company behind the <a href="https://www.thenationalnews.com/world/uk-news/2023/08/29/uk-air-traffic-control-hit-by-network-wide-failure-in-pictures/" target="_blank">widespread flight disruption</a> on Monday should be made to cough up and rules should be put in place to prevent it from passing on the costs to airlines. National Air Traffic Services (Nats), the company responsible for air traffic control in the UK, has apologised to customers affected by the chaos, including those who are still stranded abroad. Mr Walsh, <a href="https://www.thenationalnews.com/business/aviation/willie-walsh-to-retire-from-british-airways-parent-company-iag-1.961978" target="_blank">a former boss of British Airways</a>, said it is “very unfair” that Nats “doesn’t pay a single penny” for the problem. “You’re looking at hundreds of thousands of customers impacted by cancellations,” Mr Walsh told BBC Radio 4’s <i>Today</i> programme. “And that doesn’t take into account the hundreds of thousands of passengers impacted by delays on the day. So it’s considerable disruption. “We’re looking at costs in the tens of millions.” He said while it is too early to put a precise figure on the bill airlines would have for the disruption, he estimated it would be “close to £100 million”. Mr Walsh said he would like to see the Civil Aviation Authority (CAA) introduce new rules that would force Nats to pay for the cost of issues, and prevent them from passing on this cost to airlines. “At the heart of this is a failure that should not have happened and I think Nats have a lot of questions to answer,” he said. The CAA is investigating the disruption, which resulted in more than 1,000 flights being cancelled on Monday, Tuesday and Wednesday. The UK government has said the possibility of a cyber attack causing the issue has been ruled out. Reports suggest a French airline’s entry of incorrect data into the air traffic control system may have caused the shutdown. This meant data had to be entered manually, resulting in significant delays and mass cancellation of flights. Mr Walsh said he found it staggering that a single piece of inaccurate data could have triggered a complete collapse. “This system should be designed to reject data that’s incorrect, not to collapse the system,” he said, adding that if the reports are true it “demonstrates a considerable weakness that must have been there for some time”. “I’m amazed if that is the cause of this,” he said. Martin Rolfe, chief executive of Nats, said initial investigations show the failure “relates to some of the flight data we received”. He apologised to passengers affected by the disruption. Primary and backup systems used by the company responded by “suspending automatic processing”, he added.