The National Transportation Safety Board said on Wednesday that testing showed faulty altitude data in U.S. Army helicopters like the one that collided with an American Airlines plane on January 29, killing 67 near Ronald Reagan Washington National Airport.

Hearings began on the deadly midair collision between a passenger plane and a Black Hawk helicopter over Washington, D.C., in January.

On Wednesday morning, the NTSB released thousands of pages of evidence from the crash and the subsequent investigation -- including new video from the end of the runway showing the crash that killed 67 people.