How are approach categories determined?

• A. By aircraft weight
• B. By maximum demonstrated crosswind
• C. VSO x 1.3 equals Vref
• D. Landing distance

Answer: (C)

Approach category reflects how fast the airplane will fly on final approach, which sets the safe maneuvering and spacing for arrivals. That speed is Vref, the reference landing speed, and it’s derived from the airplane’s stall speed in the landing configuration with a safety margin. In practice, Vref is about 1.3 times the stall speed in landing configuration (often written as Vso × 1.3 ≈ Vref). So the way you determine the category is by taking the stall speed in the landing configuration and multiplying by 1.3 to get Vref, which then places the airplane into the appropriate approach category. The other factors—weight, maximum demonstrated crosswind, or landing distance—affect performance and certification or operations, but they don’t determine the approach category.