At their closest points, helicopters and planes routinely flew within 75 feet near the airport, according to the NTSB.

Investigators so far have highlighted several factors that may have contributed to the collision, which left 67 people dead.

Air traffic controller failed to notify commercial plane crew about approaching Army helicopter before Washington D.C.

The National Transportation Safety Board on Thursday questioned the failure of an air traffic controller to issue a warning about a potential collision in the moments before a crash between an Army ...

Investigators testifying at a hearing into the January's mid-air crash in Washington DC suggest faulty altitude data may have ...

The National Transportation Safety Board will hold three days of hearings on the fatal midair collision between a passenger ...