The NTSB released footage of a helicopter crashing after a flight instructor lost control during a lesson.
The report indicates a crew member on the fire truck heard a warning to stop but did not know the warning was for him.
Retired NASCAR driver Greg Biffle was not flying his own jet when it crashed last month.
What could have been a major disaster was averted with just seconds to spare at a busy U.S. airport.
The chair of the National Transportation Safety Board expressed concern over the possibility of a mid-air collision at Hollywood Burbank Airport.
The air traffic controller who was managing numerous aircraft around Reagan National Airport felt a "little overwhelmed" just a few minutes before an American Airlines jet collided midair with an Army helicopter near Washington D.C., an investigator said.