Wait, what? Don't all radio devices always get tested by the FCC before they are approved for sale? I'm sure they could test airplanes to never be influenced b

Wait, what? Don't all radio devices always get tested by the FCC before they are approved for sale? I'm sure they could test airplanes to never be influenced by, say, a sub 2 Watt signal and certify cellphones of never exceeding 2 Watts of signal power.