Aeroplane Performance Category

Aeroplane Performance Categories (A through E) classify aircraft based on their indicated airspeed at threshold (Vat) for instrument approach procedure design. The categories determine minimum turn radii, segment lengths, and obstacle clearance areas.

• Cat A: Vat < 91 kt (small single-engine, light twins)
• Cat B: 91–120 kt (turboprops, some light jets)
• Cat C: 121–140 kt (narrowbody jets like A320, B737)
• Cat D: 141–165 kt (widebody jets like B777, A340)
• Cat E: 166–210 kt (military fast jets)

Approach minima and circling radii increase with higher categories.