Definition
An aircraft approach category for airplanes that fly the final approach at a speed of less than 91 knots, calculated as 1.3 times the stall speed in the landing configuration at maximum certificated landing weight (V_SO). Approach categories (A through E) determine which approach minimums and circling protected airspace apply when flying an instrument approach.
Plain English
A grouping for the slowest airplanes on final approach -- those that fly the approach below 91 knots. The category an airplane falls into decides which set of landing minimums on the approach chart the pilot must use.
Context Anchor
Seen in instrument approach procedure guidance and on approach charts when deciding which speed-based procedure limits or minimums apply.
Derivation
The category system groups airplanes by approach speed because faster airplanes need more room to maneuver, especially when circling to land. Category A is the first and slowest band, so it captures light, low-speed airplanes -- typical training and personal aircraft.
Why Pilots Care
Determines the approach category, which sets the speeds, turn radii, and landing minima the pilot must use.
Intuition Check
Category A does not mean the airplane is better, safer, or more advanced. It means the airplane belongs to the slowest FAA approach-speed group.
Example Sentence 1
Flying the approach at 85 knots in his Cessna 172, he used the Category A minimums on the approach plate.
Example Sentence 2
Category A airplanes can often use lower decision altitudes on the same instrument approach than faster aircraft categories.