WASHINGTON >> Airline pilots flying into Washington, D.C., have reported nearly a dozen near misses that were scarily similar to this week’s midair collision that killed 67 people — the type of close calls that led one aviator to complain that Reagan National Airport was “probably the most dangerous” in the nation.

An Associated Press review of a federal database that catalogs such concerns found scores of reports of near-misses and warnings about congested skies over the nation’s capital, with pilots repeatedly complaining about military helicopters getting too close to passenger jets.

Last May, one of those helicopters passed just 300 feet (91 meters) below a commercial airliner, triggering a cockpit collision avoidance alert and prompting the jet’s pilot to file a report in the Aviation Safety Reporting System, a database maintained by NASA that allows pilots and crew to submit voluntary, anonymous and confidential safety concerns.

“I never saw it,” the jetliner pilot wrote, adding that he “never received a warning” about the helicopter from air traffic controllers.

Such complaints highlighted the tension that has developed between commercial airline pilots unnerved by the helicopters and the military units that have critical national security duties and must maintain flying skills to execute them.

It is not clear if federal authorities were aware of such concerns or took any steps to mitigate the risks. But on Friday, the Federal Aviation Administration paused almost all helicopter flights from operating near the airport, with exceptions for police and emergency response. The president’s helicopter transport, Marine One, is also exempt.

The pause came after an Army Black Hawk helicopter on a nighttime training run collided with an American Airlines jet that was about to land at the airport Wednesday night, plunging both into the dark, cold Potomac River. No one survived.

Investigators are examining whether the helicopter was flying higher than its allowed limit and whether control tower staffing was an issue. A preliminary FAA report noted that one controller was performing duties typically handled by two people at certain times of the day.

In the days since the crash, some officials have questioned why the military flies so close to the airport.

“I have not yet heard a good reason why military helicopters are doing training exercises in the same airspace as commercial airliners — at night and with peak congestion. I hope these exercises in Reagan airspace will be suspended indefinitely until the investigation is complete,” Sen. Josh Hawley, Missouri Republican, tweeted.

More than a half dozen military, federal and local agencies operate helicopters in the airspace near Ronald Reagan Washington National Airport, and they need those same air routes to train for and execute their missions, current and former Army pilots said.

The Black Hawk lost in the collision was part of Fort Belvoir’s Virginia’s 12th Aviation Battalion, which “has had some classified, very important missions related to our nation’s worst day,” said Brad Bowman, a Blackhawk pilot who served in 12th Aviation Battalion for two years, referring to 9/11. “You want to have training be as realistic as possible. And that means trying to replicate what you’re actually going to be doing when you conduct your mission.”

In an attack, the unit is tasked with ensuring continuity of government by getting officials to secure locations, which means being able to fly officials from the White House, Pentagon and other locations. After the Sept. 11, 2001, attacks, Bowman took part in managing some of those flights, he said.

“Anyone who suggests that we can’t have military helicopters flying in Washington, D.C., doesn’t understand national security and the threats we confront and what is necessary to defend our citizens,” Bowman said.

The unit also ferries high-ranking military and government officials around the region, missions that are flown “every day by multiple aircraft,” said Jonathan Koziol, chief of staff for Army aviation. “The Pentagon’s right there. And we have to go in and pick up Pentagon leaders.”