This definition appears very frequently
Samples in periodicals archive:
The Guidance, Navigation, and Control Conference is the largest forum dedicated to guidance, navigation, and control (GNC) serving the aerospace community.
Guidance Navigation and Control Systems from Apollo Training Manual "Apollo Spacecraft & Systems Familiarization" (March 13, 1968) Command and Service Module
The Apollo Primary Guidance, Navigation and Control System (PGNCS) (pronounced pings) was a self-contained inertial guidance system that allowed Apollo spacecraft to...