Definition
Category II (CAT II) is a precision instrument approach and landing classification permitting operations to a decision height lower than 200 feet but not lower than 100 feet above the touchdown zone, with a runway visual range of not less than 1,200 feet (350 meters). CAT II approaches require specifically certified aircraft equipment, qualified flight crews, approved operating procedures, and a runway equipped to CAT II standards.
Plain English
A type of instrument approach that lets a properly equipped and trained crew descend lower and land in worse visibility than a standard ILS approach. The pilot can come down to 100 feet above the runway before having to see the runway environment to continue.
Context Anchor
Seen in instrument approach procedures, low-visibility landing discussions, and radio altimeter use, because the radio altimeter may show the height used for the Category II decision point.
Derivation
The word 'category' comes from the Greek 'kategoria,' meaning 'a class or grouping.' In aviation, ILS approaches are divided into numbered categories (I, II, III) based on how low and how blind a crew can safely fly the approach. Higher Roman numerals mean tighter limits and more demanding equipment and training.
Why Pilots Care
Permits landings in weather below Category I limits, increasing airport access while demanding verified equipment and procedures for safety.
Grounding Statement
On a Category II approach, the airplane may be only about 100 feet above the touchdown area before the crew must decide whether they can see enough to land safely.
Intuition Check
Do not confuse Category II with aircraft category, such as airplane or rotorcraft, or with aircraft approach category based on speed. Here it means a low-visibility instrument approach category.
Example Sentence 1
The crew briefed a Category II approach because the reported visibility was below CAT I minimums but the aircraft and runway were both CAT II certified.
Example Sentence 2
The aircraft's radio altimeter was required for the Category II approach because it provides the precise height call at decision height.