A Transportation Security Administration officer works at the entrance to Concourse G at Miami International Airport, Friday, Jan. 11, 2019, in Miami. The airport is closing Terminal G this weekend as the federal government shutdown stretches toward a fourth week because security screeners have been calling in sick at twice the airport's normal rate. (AP Photo/Lynne Sladky)
Transportation Security Administration officers work at a checkpoint at O'Hare airport in Chicago, Friday, Jan. 11, 2019, as the partial government shutdown continues. (AP Photo/Nam Y. Huh)
Passengers wait in line at a Transportation Security Administration checkpoint at the Philadelphia International Airport in Philadelphia, Friday, Jan. 11, 2019. (AP Photo/Matt Rourke)
The partial government shutdown is starting to strain the national aviation system, with unpaid security screeners staying home, air-traffic controllers suing the government and safety inspectors off the job.