The US government shutdown is entering its second week and the impacts are starting to play out across the country.
More than 3,000 flights were delayed on Tuesday, with one airport going hours without a single air traffic controller.
That's because federal aviation workers are expected to keep working without pay, with no end to the shutdown in sight.
What's happening at US airports?
Flights are being delayed across the United States due to a shortage of air traffic controllers and security staff, with airports in Nashville, Boston, Chicago and Philadelphia among those most impacted.
The staffing shortages are also causing safety concerns in a system already under pressure.
A busy Los Angeles airport had no traffic controller for about six hours on Monday evening, the state's governor said in a social media post.
The Federal Aviation Authority (FAA) said departures at Hollywood Burbank Airport were delayed by about two-and-a-half hours as a result.
The US has faced air traffic control shortages for more than a decade, according to Reuters, and many controllers had been working mandatory overtime and six-day weeks before the shutdown.
The latest travel advice issued by the Australian government on Wednesday included an alert for impacts on "some federal government services".
"This has included some flight delays and longer queue times at a number of airports," the advice says.
"Check with your travel provider to see if your travel plans have been affected."
What's the US government shutdown got to do with it?
The government shutdown is set to enter its eighth day on Wednesday, with party leaders seemingly still at an impasse.
Most federal workers have been forced to go on leave without pay, but those doing jobs considered essential — like federal aviation workers — are expected to continue working.
That's some 13,000 air traffic controllers and 50,000 security officers being asked to keep working without pay.
Transportation Secretary Sean Duffy said on Monday the FAA had seen a slight increase in controllers calling in sick, while air traffic staffing had also been cut by 50 per cent in some areas.
"If we don't have controllers, we're going to make sure the airspace is safe. So what we do is we'll slow traffic," Mr Duffy said on Tuesday on Fox News.
What is the government shutdown?
If a new budget is not approved before the current one expires in the US, a government shutdown is likely, because departments can't operate without funding.
The shutdown of government agencies began just after midnight last Wednesday, local time, the first in more than six years.
Democrats had been leveraging the possibility of a shutdown in an attempt to negotiate an extension to healthcare benefits, but the Republicans were not willing to compromise.
A bill to temporarily extend government funding for seven weeks was then blocked by the Senate.
All government departments deemed non-essential have closed and their workers have been suspended.
Other essential services like social security and immigration control have kept operating, with their workers to continue showing up without pay.
When will the shutdown end?
The longest shutdown in history was also under US President Donald Trump — 35 days from 2018 to 2019.
That shutdown, also the most recent, was almost two weeks longer than any before.
A "contributing catalyst" to its end was a rise in air traffic controllers calling in sick, which was causing safety risks and flight disruptions.
But with some shutdowns in recent history lasting just a few days or less, it's anyone's guess as to how long this could go on for.
Will workers be back paid?
During shutdowns, federal employees considered non-essential are put on leave without pay — that's known as being furloughed.
Essential federal workers who keep working are expected to receive back pay after the shutdown ends, following new laws Mr Trump signed after the 2019 shutdown.
However, his administration on Tuesday warned they might not be — widely seen as a move to pressure lawmakers to reopen government.
But during an Oval Office meeting on Tuesday, Mr Trump suggested he would "follow the law" on back pay, minutes after saying the compensation "depends on who we're talking about" and that some workers would be taken care of "in a different way".
ABC/Wires
