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.

The National Transportation Safety Board is seeking more flight restrictions on helicopters at around Ronald Reagan Washington National Airport.

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.