As the federal government shutdown stretches into its second week, flights at the world's busiest airport in Atlanta are feeling some of the effects.

Staffing shortages led to flight delays at Hartsfield-Jackson Atlanta International Airport on Tuesday. According to tracking site Flight Aware, 13% of flights departing and 10% of flights arriving at the Atlanta airport were delayed. Other airports had greater delays, including 25% of flights leaving Chicago's O'Hare International Airport.

The Federal Aviation Administration reported staffing issues at airports in Nashville, Boston, Dallas, Chicago, and Philadelphia, and at its air traffic control centers in Atlanta, Houston, and the Dallas-Fort Worth area. 

Despite the traffic snags, about 92% of the more than 23,600 flights departing from U.S. airports as of Tuesday afternoon took off on time, according to aviation analytics firm Cirium.

On Monday, Transportation Secretary Sean Duffy stated that there has already been an increase in air traffic controllers calling out sick at several locations. When there aren't enough controllers, the FAA must reduce the number of takeoffs and landings to maintain safety, which in turn causes flight delays and possible cancellations.

Rising risk of flight disruptions during the shutdown

As federal workers whose jobs are deemed critical continue to work without pay, the chance that the shutdown may disrupt travel plans grows. 

Caleb Harmon Marshal, an airport travel consultant and writer of "Gate Access," said that a shutdown that drags on could cause some challenges for travelers in the coming days and weeks.

"You might be on the tarmac a little longer. You might see slower takeoffs because there's less people directing traffic," Marshall said.

Even if Atlanta's air traffic controllers come to work, the effect of national understaffing still could cause problems, he said.

"Connection-wise, it could cause delays. When you're delaying traffic from taking off at these airports, that's going to delay the connecting flight at the Atlanta airport," he said.

TSA employee struggling as shutdown continues

Even before you board your flight, staffing problems could arise when it comes to TSA security screenings.

Johnny Jones, secretary-treasurer of the American Federation of Government Employees chapter that represents TSA workers, said he was hearing concerns from members about how they will be able to pay bills, including child support and mortgage payments, and if they're at risk for termination if they have to miss work during the shutdown.

"The employees are struggling. They're assessing what they need to do, and they're assessing how this is all going to work out," said Jones, who has worked as a screener since the TSA was established.

Some TSA officers have already called in sick, but Jones said he did not think the numbers were big enough to cause significant problems and delays at airports at this time.

Marshall praised the city's response to the situation, saying Atlanta officials are stepping in to provide assistance to TSA officers, including meal vouchers and parking.

"They're doing everything they can to make sure these workers come to work," he said.

The Associated Press contributed to this report.