The U.S. Federal Aviation Administration (FAA) said operators of Boeing 787s need to take precautions when landing on runways at airports where service providers are going to deploy 5G services from next week.

The FAA said 5G interference could prevent engine and braking systems from transitioning to landing mode, which could prevent an aircraft from stopping on the runway, Reuters reported.

The directive requires crews to be aware of this risk and to adopt specific safety procedures when landing on these runways. It affects 137 U.S. aircraft and 1,010 planes worldwide.

AT&T and Verizon, which won nearly all of the C-Band airwaves in an $80 billion 5G spectrum auction last year, on Jan. 3 agreed to buffer zones around 50 airports to reduce interference risks. They agreed to delay deployment of 5G network on C-Band spectrum for two weeks.

The FAA directive prohibits operators from dispatching or releasing 787s to affected airports when certain braking and anti-skid functions on the airplane are inoperable.

The FAA is expected to detail alternative compliance for some specific airplane types and some airports before Wednesday.

The FAA on Thursday issued nearly 1,500 notices detailing the extent of potential impact of 5G services.

The notices show where aircraft with untested altimeters or that need retrofitting or replacement will be unable to perform low-visibility landings where 5G is deployed.

On Jan. 7, the FAA disclosed the 50 U.S. airports that will have 5G buffer zones, including in New York City, Los Angeles, Chicago, Las Vegas, Minneapolis, Detroit, Dallas, Philadelphia, Seattle and Miami.

On Thursday, Airports Council International – North America urged a delay 5G implementation to avoid widespread disruption across the U.S air transportation system.

“More than 100 airports and heliports within 46 of the largest metropolitan areas of the country will have their low visibility approach procedures closed due to potential radio frequency,” the airport trade group said.