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

Investigators revealed that the U.S. Army Black Hawk helicopter that collided with American Airlines Flight 5342 was flying about 100 feet higher than it should have been, and also stated the helicopter crew was warned about the incoming jet two times.

The National Transportation Safety Board plans to brief reporters Friday on its investigation into the tragic midair collision between an American Airlines passenger jet and an Army helicopter in January.