Definition
An aircraft approach category defined by a reference landing speed (V REF) of 141 knots or more but less than 166 knots. Approach categories are used to determine which instrument approach minimums (visibility and circling minima) apply to a given aircraft, based on its approach speed.
Plain English
A grouping for faster aircraft when flying instrument approaches. If the aircraft's landing reference speed is between 141 and 165 knots, it falls into this group, and the pilot must use the minimums printed for that group on the approach chart.
Context Anchor
Seen in runway incursion discussions, safety reports, and training material that classifies how serious a runway event was.
Derivation
Category comes from an old Greek word meaning a class or kind of thing. In this use, the FAA is placing runway incursions into severity classes, with the letter D identifying the least serious class in the main A-through-D scale.
Why Pilots Care
Proper classification supports accurate safety data, helps airports improve procedures, and ensures even low-severity events are tracked before they become serious.
Intuition Check
Do not read Category D as simply “not serious.” It still means a runway incursion occurred; it was just classified as having no immediate safety consequence.
Example Sentence 1
Because the Citation flies its approaches at 145 knots, the crew used the Category D minimums on the ILS chart.
Example Sentence 2
Although the pilot taxied onto the active runway without clearance, the event was classified Category D since the next arrival was still five miles out.