While aircraft have become increasingly safer in flight, runway incursions remain a critical and under-addressed danger. These dangerous events arise from a complex interplay of human, organizational, and technological factors among three key players: Air traffic controllers and the crews of converging aircrafts.

The Associated Press is providing live video of the scene of the plane crash near Washington’s Reagan Airport:

A jet carrying 60 passengers and four crew members collided Wednesday with an Army helicopter while landing at Ronald Reagan National Airport in Arlington County, prompting a large search-and-rescue o