A couple of points.
1. I would not really be surprised if the radio altimeters didn't have too much band filtering - until now, that part of the spectrum wasn't really used too much so why would they add the cost?
2. Most of the decision making on this issue would have occurred under previous (US) government and FCC administration. Similar problems occurred with GPS systems and '4G' transmitter spectrum allocation (and are also still ongoing).
3. The FAA appears to have been under some constraints - resulting in the 737-MAX certification fustercluck. Prior to that we had the battery issue.
4. There seems to (have been ?) a bit of a disconnect between a number of US government agencies. This may have been fall-out results from lack of communication between FAA & FCC & ??
Just my reading of it.
Biting the hand that feeds IT
