The Federal Aviation Administration said Thursday it had cleared more than three-quarters of the nation’s commercial fleet to land at airports where interference from 5G signals could pose a danger in bad weather, but indicated that some planes might never secure approvals.

The agency has been reviewing devices called radar altimeters to determine whether they can still provide reliable measurements of altitude – critical information for landing in bad visibility – in areas with 5G towers. The potential for disruption became clear Thursday, when San Francisco-bound flights were diverted and others were forced to circle as poor visibility collided with the rollout of the new wireless networks.

The diverted flights involved planes that had not been cleared to land where 5G could interfere with radio altimeters. The diversions are the latest challenge in a rollout that mostly spared large airports and airlines but has raised fresh questions for smaller regional carriers.

The FAA issued a bulletin Thursday warning that diversions were possible at eight airports across the country where bad weather was forecast “due to the nationwide expansion of 5G C-Band and the potential for radio altimeter interference.”... Read More: Washington Post