Who must designate the station control operator?

In amateur radio, the station licensee is the individual who has been granted the call sign and the station license by the FCC. Because the licensee holds ultimate legal responsibility for everything transmitted by that station, they are the ones who must designate the control operator. The control operator is the person physically or remotely controlling the transmissions at any given moment. The station licensee often acts as the control operator themselves, but they can designate another licensed amateur to do so when appropriate. The FCC sets the regulations but does not micromanage who is operating a specific station on a given day. Likewise, frequency coordinators manage local repeater spectrum, not individual station operation assignments.