Definition
Category A is an aircraft approach category for aircraft with a reference landing speed (Vref) of less than 91 knots. Approach categories are used on instrument approach charts to determine which set of minimums (visibility and circling approach values) applies to a given aircraft, based on its approach speed.
Plain English
Category A is the slowest group of aircraft on instrument approach charts. If your aircraft crosses the runway threshold at less than 91 knots, you use the Category A numbers when reading the chart's minimums.
Context Anchor
Seen on instrument approach charts, including procedure turn information and minimums that are listed by aircraft category.
Derivation
Category comes from a Greek word meaning a class or group. In this use, Category A is simply the first speed group used to organize aircraft for instrument procedure design.
Why Pilots Care
It sets the exact size of the protected airspace during a procedure turn; flying outside the category's radius can place the aircraft in unprotected airspace.
Intuition Check
Do not read Category A as a quality rating or a general label for small airplanes. Here it means a specific FAA approach-speed group: less than 91 knots.
Example Sentence 1
Flying the Cessna 172 at 65 knots on final, the pilot used the Category A minimums on the ILS approach chart.
Example Sentence 2
Light single-engine aircraft usually operate as Category A on instrument approaches.