The partial government shutdown has started to strain the national aviation system, with unpaid security screeners staying home, air-traffic controllers suing the government and safety inspectors off the job. Miami International Airport is providing the most visible evidence yet that the shutdown is, at the very least, making air travel less convenient. Facing double the usual number of absences among unpaid Transportation Security Administration (TSA) screeners, Miami airport closed one of its concourses for most of Saturday, Sunday and Monday to make sure the TSA can adequately staff the remaining security checkpoints. Passengers departing Miami International Airport endured unusually long waits at security checkpoints.

The government shutdown also led to a serious security breach at Atlanta Hartsfield-Jackson International Airport, as a traveler carrying a firearm flew to Tokyo Narita International Airport on Jan. 3, according to a statement from the TSA. "The TSA has determined standard procedures were not followed and a passenger did in fact pass through a standard screening TSA checkpoint with a firearm at Hartsfield-Jackson Atlanta International Airport on the morning of Jan. 3," it said in a statement, as reported by CNN.

Since Dec. 22, some 800,000 U.S. federal employees have been on mandatory leave or working without pay because President Donald Trump and Congress have been at an impasse over $5.7 billion in funding the president wants in order to build a wall on the border with Mexico.

TSA chief David Pekoske wrote on Friday that he had approved a $500 bonus for officers at checkpoints who have worked without pay in what is now the longest government shutdown in U.S. history. "While I realize this is not what you are owed for your hard work," Pekoske tweeted, "I hope these actions alleviate some of the financial hardship many of you are facing." Meanwhile, about 10,000 air traffic controllers under the Federal Aviation Administration (FAA) continue to work without pay. Last Friday, their union, the National Air Traffic Controllers Association, filed a lawsuit in federal court in Washington and asked for an order that its members get paid. Union President Paul Rinaldi said 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. There is no indication that this is happening yet.