The White House says a contractor replacing copper wire with fibre at a remote Federal Aviation Administration site overloaded the aging control system on Friday, grounding U.S. flights and prompting Sean Duffy to link the outage to an L3Harris contractor while seeking $30 billion US to modernize FAA infrastructure. Airlines are still catching up, with about 4,100 U.S. departures cancelled by midday Saturday, Air Canada scrapping some 250 flights affecting 27,000 passengers, and affected travellers told to contact carriers directly.