Final answer:
Pilots must not complete an IFR approach unless the RVR is at least 2400 ft or the ground visibility is at least 1/2 SM to ensure safety during landing under limited visibility.
Step-by-step explanation:
Pilots are prohibited from completing any Instrument Flight Rules (IFR) approach to the runway unless the Runway Visual Range (RVR) is no less than 2400 feet, or the reported airport ground visibility is no less than 1/2 statute mile (SM). These minimum visibility requirements ensure pilot and aircraft safety during approach and landing operations under IFR conditions. It's important for pilots to adhere strictly to visibility minima to maintain operational safety standards.