It is the second of three days of witness testimony and public inquiry by the National Transportation Safety Board into the January midair crash over the Potomac River.

The National Transportation Safety Board will wrap up its public testimony about the fatal midair crash between an Army helicopter and a commercial jet

Incorrect altitude readings on the Army helicopter that collided with a passenger plane over Washington, D.C., in January contributed to the aircraft getting too close, but air traffic controllers warned about the hazards helicopter traffic presented years before the crash.