All air traffic in the United States was halted for over four hours after technical problems at several Air Route Traffic Control Centers disrupted radio communication and radar, cancelling thousands of flights, with European controllers banning takeoffs to the USA and Canada also curbing flights. Transportation Secretary Sean Duffy blamed inconsistent data from time-division multiplexing routers, saying an update he ordered may have overloaded them, demanded a 50 billion dollar budget for new infrastructure, and said more outages will come; the report also notes the recent rollout of the SMART AI system, Duffy's denial it was connected, and FAA layoffs under Elon Musk's leadership.