The National Transportation Safety Board opened the hearings in Washington, with plans to question witnesses and investigators about how the actions of the Federal Aviation Administration and its air traffic controllers and the Army may have contributed to the nation's deadliest plane crash since November 2001.
The American Airlines plane from Wichita, Kansas, collided with a Black Hawk helicopter while coming into land at Ronald Reagan National Airport and was the first in a string of crashes and near misses this year that have alarmed officials and the traveling public, despite statistics that still show flying remains the safest form of transportation.
Animation, video show the crash
The hearing opened Wednesday with a video animation showing where the helicopter and airliner were leading up to the collision. It showed how the helicopter flew above the 200 feet (61 meters) altitude limit on the helicopter route before colliding with the plane.
Investigators said Wednesday the flight data recorder showed the helicopter was actually 80 feet to 100 feet (24 to 30 meters) higher than the barometric altimeter the pilots relied upon showed they were flying. So the NTSB conducted tests on three other helicopters from the same unit in a flight over the same area and found similar discrepancies in their altimeters.
Previously disclosed air traffic control audio had the helicopter pilot telling the controller twice that they saw the airplane and would avoid it. The animation ended with surveillance video showing the helicopter colliding with the plane in a fiery crash.
