Originally Posted by
Freight Dawg
Please reread my first three sentences. The concern isn’t for Boeing guys, it’s for light aircraft. Many Cessna, Pipers, etc have very limited backups, if any. Due to the ADS-B mandate, during a GPS outage their position will only be know by primary radar. All transponder, including Mode C, functions will be inoperative.
I think you are wrong about mode C being inoperative. When I was in a known jammed area I asked atc if they had our ADS -B and they said no but they still had mode C.