The crash of an American Airlines passenger jet and a U.S. Army Black Hawk helicopter near Reagan Washington National Airport on Wednesday highlighted issues around the congested airspace shared by civilian and military aircraft over the U.

An American Airlines jet carrying 60 passengers and four crew members collided Wednesday with an Army helicopter while landing at Ronald Reagan National Airport near Washington, prompting a large search-and-rescue operation in the nearby Potomac River.

The Federal Aviation Administration (FAA) is investigating a midair collision between an American Airlines aircraft (NASDAQ:AAL) and a helicopter in Washington, DC, the United States. "A PSA Airlines Bombardier CRJ700 regional jet collided in midair with Sikorsky H-60 helicopter while on approach to Runway 33 at Reagan Washington National Airport