Last month, an American Airlines passenger jet and an Army helicopter collided as the plane prepared to land at Washington D

The National Transportation Safety Board provided an update on Friday into the investigation of the deadly Army Black Hawk helicopter and American Airlines flight collision.

The Army was one of 28 government agencies authorized to fly helicopters near Ronald Reagan National Airport before its Black Hawk helicopter collided with an American Airlines passenger jet last week,

LIVE: Watch the NTSB press conference in the video player above. The collision was the deadliest plane crash in the U.S. since 2001, when a jet slammed into a New York City neighborhood just after takeoff,