This is not the airlines problem: the airlines have type certified transport/commuter category aircraft with all kinds of radios - include the radar altimeters

This is not the airlines problem: the airlines have type certified transport/commuter category aircraft with all kinds of radios - include the radar altimeters that are the problem here - that are required to meet exact performance specifications - which they did. The FAA waited until December to issue airworthiness directives that limit the ability of the airlines to rely on radar altimeters under certain circumstances. The background here appears to be some kind of pissing match between US government agencies including the FAA, the FCC and the NTIA. What exactly do you think the airlines were supposed to do here? Go out and have all their radar altimeters replaced? Replaced with what? The required standards haven't changed, and it's the FAA that writes the standard (technical service orders). This is also not a "smoke testing" problem. This is a "on the worst day, in the worst set of circumstances, what is the degree of compromise of the assumed safety margins" question.