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.
Pittsburgh International Airport, meanwhile, delivered lunches Friday to TSA workers and air traffic controllers, and they plan to do so every Friday until the shutdown ends.
Unions will hold a rally on Thursday on Capitol Hill urging an end to the shutdown.
"The uncertainty is just unreal", said Michael Smith, who is a TSA transportation security officer.
Democratic congressman Bennie Thompson, the new chairman of the House Homeland Security Committee, told the TSA chief in a letter this week that it was "only reasonable to expect officer call outs and resignations to increase the longer the shutdown lasts".
In a wave of what one federal official has dubbed as the "blue flu" - a nod to the blue shirts worn by TSA officers - hundreds of TSA screeners at at least four major airports have called out from their shifts since the shutdown began in December.
57-thousand TSA employees were not paid Friday as the potentially longest shutdown in US history continues.
TSA said that on Tuesday it screened 1.73 million passengers and 99.9 percent of passengers waited less than 30 minutes. For employees, the consequences are getting real as they're about to miss their first paycheck on Friday.
Kristin Simms, local President of the National Air Traffic Controllers Association at Oakland Tower, said the safety of departures and arrivals is a top priority even though staffing is already down. It gave few numbers but issued a statement Friday saying that more have been missing work since the Christmas and New Year's holidays.
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". After the skipped check, Shuker said it may only be days before some workers can't afford to travel to work.
Union President Paul Rinaldi says there is already a shortage of controllers, and if current controllers decide to retire - about 1,900 are eligible - the government could be forced to restrict air traffic, creating flight delays.