The National Transportation Safety Board on Tuesday called for immediate changes at Ronald Reagan Washington National Airport, saying the current helicopter routes around the busy airport "pose an intolerable risk to aviation safety.

The deadly crash took place in January when a military helicopter collided with a passenger jet, killing 67 people.

Helicopters should not be allowed to travel over a four-mile stretch over the Potomac River following the deadly air collision near Washington in January, according to urgent safety