Officials want to permanently keep helicopters away from commercial jets taking off and landing at a busy Washington, D.C., airport after the deadliest U.S. aviation accident in more than two decades.

The airspace around Ronald Reagan Washington National Airport has long been problematic due to heavy military and commercial flight activity in the nation’s capital, according to industry insiders.

More than 280 flights were delayed Friday at Reagan National Airport (DCA) due to the ongoing plane crash investigation. Some travelers were frustrated because the reason for the delays was not communicated to the passengers on all of the flights.