The deadly crash took place in January when a military helicopter collided with a passenger jet, killing 67 people.

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

The NTSB says the current helicopter routes around the busy airport "pose an intolerable risk to aviation safety" in the wake of January's collision that killed 67 people.

Helicopter traffic should be permanently banned near Ronald Reagan Washington National Airport during certain periods to alleviate congestion and avoid a repeat of the deadly midair collision that occurred there in January,

US air crash investigators have recommended restricting helicopter flights in certain areas near Washington DC's Reagan National Airport following January's deadly mid-air collision. Citing an "intolerable risk to aviation safety",

Investigators issued their preliminary report Tuesday in the probe into the devastating crash between an American Airlines plane and a U.S. Army Black Hawk helicopter.