Nearly 50 per cent of the 30 busiest US airports faced shortages of air traffic controllers, the Federal Aviation Administration said on Friday, leading to flight delays nationwide as a federal government shutdown hit its 31st day.

The absence of controllers on Friday is by far the most widespread since the shutdown began, with one of the worst-hit regions being New York, where 80 per cent of air traffic controllers were out, the agency said.

At least 35 FAA facilities, including several at the largest US airports, reported staffing problems. Airports affected included facilities in New York, Austin, Newark, Phoenix, Washington, Nashville, Dallas and Denver. At some airports, delays averaged one hour or more.

The shutdown has forced 13,000 air traffic controllers and 50,000 Transportati

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