The Federal Aviation Administration has launched an investigation into whether major US airlines complied with its emergency order requiring carriers to cut flights at 40 of the nation’s busiest airports during the 43-day federal government shutdown. The agency has contacted airlines that operate more than 10 daily flights at any affected airport and is seeking documentation showing compliance. Reports suggest that some airlines may have exceeded the mandated flight-reduction limits, which could result in civil penalties. According to Cirium data, airlines collectively reduced schedules by only about 2% on November 14, raising concerns about non-compliance. The FAA has not publicly identified which carriers it believes may have exceeded the limits or how many potential violations it is examining.