The crew of the Army helicopter that collided in midair with an American Airlines jet near Washington, D.C.'s Ronald Reagan National Airport may have had inaccurate altitude readings in the moments before the crash,

The National Transportation Safety Board said the helicopter’s cockpit voice recorder didn’t capture key directions from air-traffic control and is investigating whether the crew might have seen a different altitude on the flight instruments.

The Army helicopter that crashed into an American Airlines jet in Washington, D.C. may not have heard important instructions from air traffic controllers, according to the National Transportation Safety Board.

The National Transportation Safety Board gave an update on its investigation into the deadly midair collision between an American Airlines plane and a Black Hawk helicopter.