Key takeaways from NTSB’s preliminary report on deadly midair collision between DC plane and military helicopter

The National Transportation Safety Board on Tuesday recommended that helicopter traffic be banned from a four-mile stretch over the Potomac River when flights are landing at Ronald Reagan National Airport.

​ The National Transportation Safety Board on Tuesday recommended that helicopter traffic be banned from a four-mile stretch over the Potomac River when flights are landing at Ronald Reagan National Airport. Read More Breaking News, Latest News and Videos | CNN