The TSA said unscheduled absences of its passenger screeners reached 7.6 percent Monday, more than twice the rate from a year ago. TSA's 51,000 officers are among the 420,000 federal employees deemed essential who are ordered to work despite not receiving a regular paycheck during the shutdown. The officers missed their first scheduled check Friday. The agency said it was handing out $500 bonuses to officers.

The Transportation Security Administration's standard wait time is a half-hour or less. The Atlanta airport is encouraging travelers to arrive at the airport three hours before domestic flights.

Travelers at Hartsfield-Jackson Atlanta International Airport, the world's busiest airport, faced hour-long lines to get through security Monday after the airport shut security lanes "due to the shutdown," spokeswoman Elise Durham said.

Shortages of federal airport security workers in the partial U.S. government shutdown prompted several large U.S. airports to close security lanes Monday, as the impasse over funding for a wall along the U.S. border with Mexico rippled throughout the aviation industry.

The aviation industry has been among the most vocal of the shutdown. The union representing air traffic controllers sued the Trump administration last week over frozen pay during the shutdown, and several industry groups demonstrated in Washington last week.

Washington Dulles International Airport also consolidated security checkpoints after the region was hit by a snowstorm over the weekend. TSA spokesman Michael Bilello said more officers called out than usually do during a snowstorm.

At Houston's George Bush Intercontinental Airport, the Terminal B security checkpoint — which was closed on Sunday — will remain closed until at least late afternoon on Monday because of staffing issues, spokesman Patrick Trahan said. The TSA's Bilello said that terminal's checkpoint will be closed until Wednesday.

The airport is a hub of United Airlines, and the carrier recommended travelers get to the airport early to go through other terminals' checkpoints. Gates and lounges in Terminal B were open, a United spokeswoman said.

Miami International Airport closed one of its terminals early over the weekend to deal with the shortfall, a spokesman said.

The shutdown has raised questions about air carriers' ability to follow through with scheduled events.

Delta Air Lines scheduled a launch Jan. 31 of its brand-new Airbus A220s, a plane it's using to court business travelers with bigger seats and windows. Also, Southwest Airlines needs federal approval to begin service to Hawaii, and the shutdown is delaying that plan.

Airlines need Federal Aviation Administration inspectors' approval to debut new aircraft. The FAA called about 500 furloughed safety inspectors back to work. FAA safety inspectors oversee and approve new aircraft, airplane maintenance and personnel such as pilots and mechanics, among other areas.

Those inspectors are working without pay and more are likely to be called in this week, spokesman Gregory Martin said.

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