Definition
A precision instrument approach and landing classification with no decision height and no runway visual range limitation, permitting operations to and along the surface of the runway in zero-zero visibility conditions. CAT IIIc requires aircraft, airborne equipment, flight crew, and ground facilities certified to the highest precision approach standards, including auto-land and rollout guidance capable of taxi guidance to the gate.
Plain English
The most demanding category of instrument approach, allowing a pilot to land and roll out on the runway when there is essentially no visibility at all. The aircraft systems fly the approach, land, and steer along the runway automatically.
Context Anchor
Seen in instrument approach discussions comparing CAT II, CAT IIIa, CAT IIIb, and CAT IIIc landing minimums.
Derivation
CAT' is short for 'Category.' The Roman numeral 'III' marks it as the third and most capable group of precision approaches, and the lowercase 'c' is the third and most demanding sub-level within that group, where visibility limits drop to zero.
Why Pilots Care
It represents the theoretical limit of all-weather operations, though such procedures are not yet authorized for normal line operations due to equipment requirements.
Grounding Statement
Picture being aligned with the runway by approved systems while the view outside is still blank; CAT IIIc is the category that describes that extreme end of instrument landing approval.
Intuition Check
Do not read CAT IIIc as simply “a little lower than CAT IIIb.” It specifically means no decision height and no runway visual range minimum.
Example Sentence 1
CAT IIIc would allow landing and rollout with no visibility at all, but no airport is currently certified for that level of operation.
Example Sentence 2
During preflight planning the crew confirmed the runway lighting and rollout guidance met CAT IIIc standards.