In the three years before the deadly collision between an Army helicopter and an American Airlines flight near Reagan National Airport, at least two other pilots reported near-misses with helicopters while landing at the airport,

The deadly mid-air collision over Washington, D.C., has reignited concerns over air traffic congestion and safety risks at Ronald Reagan Washington National Airport, a tightly packed aviation hub that shares airspace with military and government flights.

The crash disrupted flights at Reagan National Airport. Several dozen emergency crews could be seen at the scene of the crash, apparently just south of Reagan National Airport’s upper departure area,