The deadly mid-air collision over Washington, D.C., has reignited concerns over air traffic congestion and safety risks at Ronald Reagan Washington National Airport, a tightly packed aviation hub that shares airspace with military and government flights.

In the aftermath of the midair collision between an American Airlines plane and a U.S. Army Black Hawk helicopter on Wednesday, Jan. 29, the Federal Aviation Administration is indefinitely restricting helicopter flights in the vicinity of Washington,

Daniel Driscoll, President Trump’s pick for Army secretary, said during his Thursday confirmation hearing that the service may not want to risk training around an airport as busy as Ronald Reagan Washington National Airport.

If changes aren't made, that near-miss becomes a mid-air collision,” one aviation safety expert said. “Unfortunately, that's what we had last night.”

Airport preferred by Washington lawmakers and lobbyists lies in some of the most congested airspace in the country.