The military helicopter that collided with a regional jet near Ronald Reagan Washington National Airport, in a crash that killed all 67 people aboard both aircraft, was a UH-60 Black Hawk, considered the “workhorse” of U.

Military spokesman Ron McLendon II said the Army is joining an investigation into the crash headed by the National Transportation Security Board.

A Black Hawk helicopter can transport up to "12 fully equipped, seated troops in combat," according to Lockheed Martin, the weapons company that builds the helicopter. There are about 5,000 of these helicopters in use by the United States Military.