"We are having very productive discussions and we will figure this out," FAA Administrator Steve Dickson said at an event in Washington. "It remains to be seen what mitigations - whether it's adjustments to deployment or actions that we need to take within the aviation sector - what those will look like."
Earlier this month, AT&T and Verizon Communications agreed to delay the commercial launch of C-band wireless service from Dec. 5 until early January.
The FAA issued a Nov. 2 bulletin alerting manufacturers, operators and pilots that action may be needed to address potential interference caused by the 5G deployment with sensitive aircraft electronics like radio altimeters.
The FAA bulletin said operators "should be prepared for the possibility that interference from 5G transmitters and other technology could cause certain safety equipment to malfunction."
Wireless trade group CTIA said in a letter to the White House that in nearly 40 other countries, "C-Band 5G spectrum is deployed and planes land safely every day without any evidence of harmful interference."
CTIA asked the Biden administration to "reject further calls to delay C-Band 5G services. Aviation safety is critically important. It is also not at risk due to C-Band 5G operations."
The FAA is considering issuing an airworthiness directive. Dickson said airlines need at least 30 days' notice.
"The industry needs some time to make adjustments to whatever requirements we're going to levy on them," he said. "If they have to change their flight planning systems or how they are getting information to pilots... Whatever it is, we've got to give time to put all those things in place."
Boeing Co, Airbus SE, US airlines, pilots and others have urged the administration "to help aviation and telecommunication industries reach acceptable mitigations." They added that it "will take significant time... to ensure they meet the FAA’s robust safety requirements."