U.S. aviation officials are no longer allowing foreign airlines to land alongside another plane when touching down at San Francisco International Airport.
The Federal Aviation Administration said it implemented the change last weekend to minimize distractions during a critical phase of flight.
The change comes in the aftermath of the Asiana Airlines crash, and on same day the FAA started advising foreign airlines to use a GPS system instead of visual reckonings when landing at SFO.
In the past, two planes could approach SFO side by side if the weather is clear. Domestic carriers can do that, but air traffic controllers are now staggering the arrivals of foreign carriers.
FAA spokesman Ian Gregor said the agency hasn't seen any significant delays as a result of the change.