Investigators so far have highlighted several factors that may have contributed to the collision, which left 67 people dead.

The pilots of a U.S. Army helicopter that collided with a passenger jet over Washington in January would've had difficulty ...

The pilots of a U.S. Army helicopter that collided with a passenger jet over Washington in January would’ve had difficulty ...

Investigators probing the January midair collision of a passenger plane and an Army helicopter over Washington that killed 67 people found the chopper was flying higher than the it should have been ...

The deadly mid-air collision at Reagan Airport in January was years in the making, the operations manager of the DCA air ...