WASHINGTON (AP) — Federal investigators looking into the cause of the January collision between a passenger jet and an Army helicopter near Washington, D.C., that killed 67 people recommended a ban on some helicopter flights Tuesday, saying the current setup “poses an intolerable risk.”

The NTSB is urging the FAA to take steps to ensure helicopter traffic is never permitted to cross arrival and departure paths at Reagan Washington National Airport (DCA), eliminating a risk that the board suggests should have been addressed before the Jan. 29 midair collision of a regional jet and a U.S Army helicopter.

The National Transportation Safety Board said the separation between helicopters and jets in the area was insufficient and increased “chances of a midair collision.”