The Federal Aviation Administration (FAA) has cleared roughly 78% of the US commercial aircraft fleet for low-visibility approaches near C-band 5G.

The airline industry has been at odds with Verizon and AT&T over the rollout of C-band 5G. C-band is in the mid-band range of frequencies that are very close to those used by aircraft altimeters. The airline industry and FAA have been concerned that C-band could interfere with altimeters, putting aircraft at risk in low-visibility conditions.

After delays and negotiations, Verizon and AT&T began rolling out their new spectrum on January 19, and the FAA has now cleared a large portion of the US aircraft fleet for low-visibility approaches.

“The FAA issued new approvals Thursday that allow an estimated 78 percent of the U.S. commercial fleet to perform low-visibility landings at airports where wireless companies deployed 5G C-band,” the FAA’s statement reads. “This now includes some regional jets. 

“Airplane models with one of the 13 cleared altimeters include all Boeing 717, 737, 747, 757, 767, 777, 787, MD-10/-11; all Airbus A300, A310, A319, A320, A330, A340, A350 and A380 models; and some Embraer 170 and 190 regional jets.

“The FAA is working diligently to determine which altimeters are reliable and accurate where 5G is deployed in the United States. We anticipate some altimeters will be too susceptible to 5G interference. To preserve safety, aircraft with those altimeters will be prohibited from performing low-visibility landings where 5G is deployed because the altimeter could provide inaccurate information.”

The FAA says altimeters that are not deemed safe will need to be retrofitted or replaced.