"More and more planes on this busiest runway in the United States is just going to increase the chance of a significant incident," Sen. Tim Kaine warned a year ago.

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,

Political leaders had warned about the dangers of Ronald Reagan Washington National Airport in Washington, D.C. months before an American Airlines flight collided with a U.S. Army Black Hawk helicopter on its approach to the airport.