NCYankee wrote:
Are you saying that using an ICAO 3 letter call sign in lieu of the registration is not allowed?
You must radiate your callsign (the same as in your flight plan), whatever that is. For most, if not all, of “our GA”, that is in fact the registration of the plane. Air taxi companies (which is also GA) are more likely to have registered for a “company callsign” and ICAO three-letter operator prefix and to fly with a flight number (their ICAO prefix + a number).
I’m not aware of any service to provide airplanes that one doesn’t operate oneself with usage of one’s ICAO operator prefix.
