The Army Black Hawk helicopter that collided with an American Eagle passenger jet near Washington, D.C., was conducting an "annual proficiency training flight,” according to Defense Secretary Pete Hegseth.

"It was a fairly experienced crew that was doing an annual night evaluation," Hegseth said in a statement on Thursday.

He added later that the crew included a captain, a staff sergeant and chief warrant officer 2.

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Transportation Secretary Sean Duffy said that it was a clear night and both the jet and helicopter were in a "standard flight pattern" at the time of the crash. Duffy added he believes the incident could have been prevented, but expressed confidence in flight safety.

The Sikorsky UH-60 helicopter was part of the 12th Aviation Battalion at Fort Belvoir, Virginia. This type of aircraft has been in military use since the 1970s and is capable of carrying a crew of four, plus 11 fully equipped service members.

Three soldiers, whom Hegseth said were equipped with night-vision goggles, were on board the aircraft that crashed.

"The FAA, NTSB and the United States Army will investigate. The NTSB will lead the investigation," the Joint Task Force National Capitol Region said in a statement.

Washington, D.C., Fire Chief John A. Donnelly Sr. said in a Thursday morning news conference that officials do not believe there were any survivors from the passenger jet or the helicopter.

American Airlines CEO Robert Isom said 60 passengers and four crew members were on the plane.