More than two weeks after a helicopter and airplane collision over Washington killed 67 people, investigators have completed their work at the scene where the aircraft fell into the Potomac River ...

The portion of the transmission that stated 'pass behind', may not have been received by the Black Hawk crew,” NTSB Chair Jennifer Homendy said.

Investigators believe the Army helicopter crew involved in the midair collision near Washington, DC may have had inaccurate altitude readings and missed key air traffic control directions.