The Federal Aviation Administration (FAA) has cleared around 45 percent of US commercial planes for low-visibility landings at some airports where 5G C-band will be deployed but airlines have warned that a “catastrophic” aviation crisis is now imminent.

Last week, the FAA issued more than 1,400 warnings to pilots that onboard aviation systems could be disrupted by 5G C-band operations. On Sunday, the agency approved two radio altimeter models that are installed in a wide...