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A321 Neo: CAT C or Cat D?

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A321 Neo: CAT C or Cat D?

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Old 14th Apr 2021, 03:57
  #21 (permalink)  
 
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Superpilot

If "normal" isn't the right word, how about "default"?
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Old 14th Apr 2021, 04:04
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BoeingDriver99

My comment about workload was made in jest. I use full to keep things standard across the family. 3 gives a SLIGHTLY lower pitch than full in the A321, but it's hardly noticeable. At my last airline, unless there was a safety-related reason to land conf 3, we always used full. Even with one engine. It just kept things simpler.

I'm quite capable of landing with flaps 3, but prefer full. Some of my colleagues prefer 3, and use it every day. Doesn't bother me a bit.
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Old 14th Apr 2021, 09:40
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Is that an A321NEO?

CEO 321 Config 3 2.5 NU, Config Full ~ 1 NU

CEO 320 Config 3 4.5 NU, Config Full 2.5 NU
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Old 14th Apr 2021, 13:04
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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.)

Last edited by Bus Driver Man; 14th Apr 2021 at 13:49.
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Old 14th Apr 2021, 13:29
  #25 (permalink)  
 
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Originally Posted by FlightDetent
A321 CEO is designed and certified with speeds for a category C aeroplane.
Not always the case I think.
Our A321 CEOs have a max certified landing weight of 75500 kg.
The QRH gives the following VLS:
74t: 139 kts
78t: 143 kts

So with interpolation, the VREF is 140.5 kts for 75500 kg. So just within the cat C range.

However, A321 CEOs can have a max certified landing weight of 77800 kg. This will give them a VREF or Vat of 142.8 kts. So within the cat D range. And since it's based on max certified landing weight, I think that they should be considered cat D if they have the certification of this higher weight. That was the case at a different company I worked for which had those higher certified landing weights. For the lower certified max landing weight, it's definitely cat C.

As for the A321 NEO, due to the higher flap angle in config Full, lower VREF speeds are possible which will always be in the cat C range. Even with max landing weight of 79200 kg. (VREF=139 kts for 80t on the NEO.)
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Old 15th Apr 2021, 01:57
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Check Airman I thought so!
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