Aviation authorities on Friday permanently closed part of a helicopter route east and southeast of Reagan National Airport where an Army Black Hawk collided with an airliner in January, killing 67 people,

The FAA is permanently closing one key route and evaluating alternative helicopter routes after the National Transportation Safety Board this week made two urgent safety recommendations following the Jan. 29 mid-air collision of an American Airlines regional jet and an Army helicopter that killed 67 people.

The US Federal Aviation Administration detailed a series of restrictions on helicopter traffic near Ronald Reagan Washington National Airport following a deadly midair collision in January.