Unions representing air traffic controllers, pilots and flight attendants demonstrated outside the Capitol on Jan. 10, 2019 against the federal government shutdown. (Fredrick Kunkle)

Hundreds of air traffic controllers, pilots and flight attendants rallied outside the Capitol on Thursday, urging an end to the federal government shutdown.

Union leaders representing the controllers and flight crews said the longer the standoff between President Trump and Congress continues, the more their concerns about possible threats to aviation safety increase as the controllers continue do their jobs without pay for nearly three weeks. As a sharp wind cut through the crowd, others raised concerns about a slowdown in maintenance and training.

“We want to make sure we have sufficient, competent air traffic controllers at all times,” Christopher Bacon, a first officer with American Airlines who also is a representative of the Allied Pilots Association. “The safety implications are obvious, unfortunately, if they’re worrying about a paycheck — if they have other things on their mind other than ensuring they’re giving absolute, top-notch control of the pilots."

A separate protest drew hundreds of furloughed federal workers and contractors to the White House. On the lawn beside the Capitol, several speakers and audience members put the blame for the standoff on Trump, who walked out of talks with Democrats to end the shutdown. On Thursday, he traveled to the U.S.-Mexico border to make his case that a wall was necessary for border security. He also continued to blame Democrats for the shutdown.

The Association of Flight Attendants-CWA also raised several safety-related concerns as the shutdown entered its 20th day. In a letter to the president and leaders of Congress, union leaders said the shutdown has furloughed Federal Aviation Administration staff who are responsible for certifying the safety of aircraft. The group also expressed concern about the effect on the airline industry and the economy in general.

“And at the end of the day, it’s just complete nonsense,” said Paul Rinaldi, president of the National Air Traffic Controllers Association. He implored both the president and Congress to end the shutdown because of its human toll.

“Zero paychecks are hitting our bank accounts right now,” Rinaldi said. “These are real people. Real consequences.”

Several members of Congress also attended Thursday’s demonstration outside the Capitol, including Rep. Peter A. DeFazio (D-Ore.), who chairs the House Transportation and Infrastructure Committee, and Rep. Peter T. King (R-N.Y.).

Sen. Mark R. Warner (D-Va.) said that when the air traffic controllers union’s head was briefing him as a new member of Congress years ago about the basics of air safety, he “scared the hell” out of Warner about the importance of air traffic controllers in aviation safety. Warner expressed concern that the shutdown could take a toll on the air traffic controllers and flight crews and make it harder for them to do their jobs.

“Over the last two years, I thought, with Mr. Trump in the White House, things can’t get any weirder. And then every day, they get weirder,” Warner told the demonstrators. “We’re now approaching the longest government shutdown in American history. And a shutdown based on a request from this president when the Republican Party controlled the House, the Senate and the presidency. What we want to do is end this shutdown today.”

Read more Tripping:

Passenger rights groups hope new Congress prods government to police airlines more closely

New app offers one-stop shopping for subway, ride-hailing, bike-share and carpooling

Bicyclists don’t have all the answers on traffic safety. I should know — I was hit by one