The Federal Aviation Administration will be permanently restricting nonessential helicopter operations around Ronald Reagan Washington National Airport in response to January’s mid-air collision over the Potomac River involving an Army helicopter and a passenger jet that killed 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.