Voice recordings from the Black Hawk helicopter involved in the crash with a commuter plan in Washington, DC, on January 29 have been released by the NTSB in a briefing for reporters Friday.

The NTSB is turning the focus of its investigation into the Jan. 29 collision on what the Black Hawk pilots could see and hear.

The crew of an Army Black Hawk helicopter might not have heard key instructions from air traffic control before a collision with a passenger jet over the Potomac River on Jan. 29, the National Transportation Safety Board said Friday in its most detailed account of the moments before the crash that killed 67 people.