Category III ILS operations can be conducted with what characteristics under certain conditions?

• A. Higher minimums than Category I
• B. No requirement for glideslope signal
• C. Only applicable during daylight
• D. Lower or no decision height and lower minimum visibility in certain conditions

Answer: (D)

Category III ILS operations are designed to allow landing in very low visibility by using precision guidance and, when available, automatic landing systems. Under certain conditions, these operations can be conducted with decision height that is much lower than Category I—potentially no decision height at all in the most advanced CAT III configurations—and with much lower minimum visibility requirements. This capability is what enables landings when pilots would have little to no visual cues, relying on the instrument guidance and automation to complete the approach and landing safely.

These operations require the aircraft and crew to be certified for CAT III, an ILS with the necessary precision guidance and automation, and appropriate ground facilities and weather minima. The other statements don’t fit because CAT III does not impose higher minimums than Category I, glideslope signals are still part of CAT III approaches, and these operations are not restricted to daylight.