Wednesday’s fatal collision and two other incidents dramatically illustrate the challenges pilots and air traffic controllers face in the complex, security-sensitive skies above the nation’s capital.

By David Shepardson, Trevor Hunnicutt and Brad Brooks WASHINGTON (Reuters) -An American Airlines regional passenger jet and a U.S. Army Black Hawk helicopter crashed into the frigid Potomac River after a midair collision near Reagan Washington National Airport on Wednesday night,

An American Airlines flight crashed into a U.S. Army Black Hawk Helicopter over the Potomac River as it approached Ronald Reagan Washington National Airport.