U.S. Transportation Secretary Sean Duffy on Tuesday said the agency will make permanent restrictions to prevent helicopters from flying near Washington Reagan National Airport when two lesser-used runways are operational,

Federal investigators looking for the cause of the January collision between a passenger jet and an Army helicopter near Washington, D.C., that killed 67 people are recommending a ban on some helicopter flights.

After the NTSB issued two urgent safety recommendations, the secretary of transportation permanently restricted Washington Reagan National Airport airspace to nearly all helicopter traffic. The NTSB's recommendations come after January's deadly midair collision.