De facto: I think you misunderstood me. This is from Airbus FCTM
"The circling area which ensures obstacle clearance is based on a maximum speed of 180 kt for Category C aircraft (ICAO PANS-OPS and JAR OPS) "
If you are in an abnormal situation such as flap failure your Vref is going to be directly affected.On A320 , flaps 0 landing will result in a Vref+60 . So you will obviously be in a higher Category , because the Vref was directly affected and not because you chose to fly faster in a portion of the approach.
Not even talking about circling, If in abnormal condition your vref ( vref is Vat or speed at threshold) is let's say 165 kt even for a straight in ILS approach, you will use D category.
Now in normal situation regarding circle to land , you will not change your aircraft category because you are flying faster as a maximum speed has been taken into consideration for each cat A, B , C, or D
If your final approach speed Vref is within 121 and 140 kts, You are in the C category , you are allowed to fly up to 180 kt in a circle to land.
If your Vref is between 141-165 kt, you are in the D Category, you are allowed to fly up to 205 kts in a circle to land.
This is PAN OPS regulation and how obstacle clearance is calculated using the Max speed for the category.
You could be doing a low as 121 kts on final, but ICAO designed for you a circle to land protection based on 180 kt, without the need of changing your category. This has been catered for in PAN OPS
FAA, terps approach have different rules and do not have such wide protections as PAN OPS. So if you are doing 180 kts in a circle to land designed according to TERPS, you will have to use the next higher category.
If you are performing a circle to land designed according to PAN OPS regulations , wider protections with max speed are provided without having to go on the next higher category.
Airbus FCTM :In regions where FAA TERPS criteria apply, the circling areas and limit speeds are more restrictive
Last edited by Citation2; 13th Dec 2012 at 15:22.