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 National Transportation Safety Board says altimeter in the Black Hawk helicopter may have malfunctioned before the DCA mid-air collision with an American Airlines jet. All 67 people aboard died.

Analysis of black box shows ‘conflicting information’ and suggests cockpit may not have seen accurate altitude information