On Thursday, TSA employees demonstrated against the government shutdown outside Hartsfield-Jackson International Airport.
US airport security workers and air traffic controllers working without pay have been warning that security and safety could be compromised if the government shutdown continues, but the Trump administration said on Wednesday that staffing is adequate and travelers have not faced unusual delays.
Federal workers and agencies are feeling the negative impact of the shutdown.
"If this keeps up there are problems that will arise - least of which would be increased wait times for travellers".
Unions will hold a rally on Thursday on Capitol Hill urging an end to the shutdown. TSA spokesman Michael Bilello conceded that the screener absentee rate is up, but said it was only slightly higher than normal for this time of year.
"Yesterday, Jan 9, 2019, TSA experienced a rate of 5 per cent compared to a 3.6 per cent unscheduled absence rate one year ago on Jan 9, 2018", it said, lauding "the more than 51,000 officers across the country (who) remain focused on the mission".
Although the shutdown began on December 22, TSA employees still received paychecks on December 28.
U.S. Representative Bennie Thompson, chairman of the House Homeland Security committee, asked the Trump administration how it is ensuring adequate staffing at airports.
According to the American Federation of Government Employees (AFGE), more than 50,000 TSA officers and staff will most likely miss another paycheck during this shutdown. And Delta Air Lines' plans to start flying its newest aircraft, the Airbus A220, by the end of this month could also be affected.
Even before the shutdown, controllers have been working six-day weeks and 10-hour days at numerous country's busiest airports, NACTA's president Paul Rinaldi said, adding: "This staffing crisis is negatively affecting the National Airspace System, and the shutdown nearly certainly will make a bad situation worse".
As the effects of the shutdown began to ripple out, the Trump administration insisted that air travel staffing was adequate and travellers had not faced unusual delays.
Federal Aviation Administration Academy in Oklahoma City has been closed as a result of the shutdown and simulator trainings have been disrupted. The FAA suspended training and limited safety efforts to "urgent continued operational activity to protect life and property".
"Each day, the FAA's Air Traffic Controllers", the lawsuit says, "are responsible for ensuring the safe routing of tens of thousands of flights, often working lengthy, grueling overtime shifts to do so".