New Delhi, July 30 -- Three days of investigative hearings on the deadly midair collision over Washington in January begin Wednesday and aim to reveal new insights into what caused the crash between a passenger plane and an Army helicopter that killed 67 people.

The National Transportation Safety Board will 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. It's likely too early for the board to identify the cause of the crash.

The American Airlines plane from Wichita, Kansas collided with a Black Hawk helicopter while coming into land at Ronald Reagan National Airpor...