US officials say flight stoppage stemmed from ‘routine maintenance’ as travel chaos continues

Thousands of flights still canceled as officials blamed ageing air control system for nationwide grounding

The Trump administration says Friday's four-hour nationwide Federal Aviation Administration (FAA) ground stop that delayed or canceled thousands of flight stemmed from routine maintenance.

At a news briefing on Saturday, the US transportation secretary, Sean Duffy, said that the issues began when a contractor was performing routine maintenance" at a remote FAA facility to switch telecommunications lines" from copper wire to fiber optic cable.