There's an "intolerable risk to aviation safety" with helicopters and planes flying too close to one another near DCA.

Helicopter traffic should be permanently banned near Ronald Reagan Washington National Airport during certain periods to alleviate congestion and avoid a repeat of the deadly mid-air collision that occurred there in January,

The NTSB’s preliminary report on the Jan. 29 crash that killed 67 people said current helicopter routes allowed around the airport are an ‘intolerable risk to aviation safety.’