Originally Posted by
pineteam
Back on the topic: Flaps 3 max landing weight on A321 Neo will be around 153kt vapp. Faster than the A321 CEO which are Cat D In config full. Thus one of my question. How can we consider the A321 Neo a cat C aircraft when it flies much faster than some A321 cat D aircraft.
"The criterion taken into consideration for the assignment of an aircraft to a specific category is the indicated airspeed at the runway threshold (VAT
) whilst in the normal landing configuration at the maximum certified landing mass."
FCOM:
REFERENCE SPEED (VREF)
VREF is equal to the VLS of CONF FULL. VREF is used to determine the Final Approach Speed (VAPP) when a system failure affects the landing performance.
Equal to 1.23 × VS of CONF FULL.
The category of an aircraft depends on the Vat (or Vref speed, as defined by Airbus) at max landing weight with normal landing flap setting. Airbus went with Full as normal flap setting for the categorisation.
Landing with a different flap setting, higher speed due to wind correction or improved performance, or overweight landing does not change the categorisation as this is only a certification criteria. Cat C minima can still be used with higher speeds.
However, as already mentioned by someone, the circling area depends on the speed during the circling manoeuvre, so that should be taken into account for circling minima, as it can affect your obstacle clearance.
(Max circling speed for cat C is 180 kts IAS for ICAO criteria, so normally with F3 and F speed, even in overweight conditions, circling speed should not exceed 180 kts. F speed at 94t for the A321 CEO is 175 kts. Note: TERPS max circling speed is 140 kts for cat C and 165 kts for cat D.)