ICAO’s classification of approach category is based on the indicated airspeed at threshold which is equal to the stall speed (Vso) multiplied by 1.3 or stall speed (Vs1g) multiplied by 1.23 in the landing configuration at the maximum certified landing weight. If both Vso and Vs1g are available, the higher resulting Vat shall be used.
FAA’s classification is based on a speed of Vref.
Could you provide any information which regulation do you apply?
3. Both ICAO and FAA