> So "this altimeter may be inaccurate near 5G" means "this airliner may not be airworthy near 5G" which means airlines must ground those planes. No, they don'

> So "this altimeter may be inaccurate near 5G" means "this airliner may not be airworthy near 5G" which means airlines must ground those planes. No, they don't need to ground the planes. There's different types of IFR approaches available to chose from, depending on equipment and how much visibility is reported. An inoperative radio altimeter means the aircraft couldn't land using the approaches for the lowest-visibility conditions, but doesn't mean they can't land under other less-severe IFR conditions. In practice, this means the aircraft wouldn't even be dispatched if the weather forecast showed the destination's weather was below the aircraft's capabilities. They would also have enough fuel to divert to an alternate airport with better weather.