1200 is VFR. That doesn’t mean null. 7500, 7600, and 7700 are used for various emergency purposes. These are transponder codes, not radio channels. It’s a code returned when the transponder is painted with interrogative…
1200 is VFR. That doesn’t mean null. 7500, 7600, and 7700 are used for various emergency purposes. These are transponder codes, not radio channels. It’s a code returned when the transponder is painted with interrogative…