Moderators: richierich, ua900, PanAm_DC10, hOMSaR

 
hudicourt
Posts: 5
Joined: Sun Feb 20, 2011 2:21 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Mon Nov 20, 2017 7:07 pm

1) My company operated the 757 for years between Montreal, Toronto and the UK, France, Belgium, Amsterdam, Dusseldorf with single class 228 passengers. Never had trouble making the crossing, not even Westbound, except for the Nice Montreal flights which sometimes didn't make their reclear fuel.
2) We operate aircraft that have much longer range than the A321LR and none of our aircraft have crew rest facilities.
3) Granted, but I often see very heavy B777s beeing flown in the low thirties in the initial part of very long flights as well.
4) Most flights that do no carry cargo do not use all of their holds in any case for just passenger baggage.
5) I remember that we used to fly the 757 at Mach .78 or .79 as well on Ocean Crossings. In any case, such an aircraft, when used for TransAtlantic flights, will only do one round trip per day. No more. A six hour leg eastbound, a seven hour westbound leg and two two hour turnarounds add up to 17 hours. That leaves just 7 hours in the day, not enough for more than a couple short haul legs.
6) It will carry no cargo on long haul flights.
7) It can do TransAtlantic flights with a two class cabin layout and between 190 and 200 passengers
8) The A321NEO LR aircraft is part of 318/319/320/321 family and has common cockpit layout with the A330/340, allowing MFF which airlines such as Air Berlin was doing allowing a pilot to fly an A330 one day and a A321 the next.

One problem I do see, that was not raised here is the MTOW of 97 tonnes with two wheel bogies, which will probably not allow this aircraft to have the short runway performance that the 757 had. I was wondering if Airbus would re-activate the 4 wheel bogie for this option as they had for the early A320s......
 
kurtverbose
Posts: 606
Joined: Thu Jun 26, 2014 9:33 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Tue Nov 21, 2017 8:40 am

hudicourt wrote:
One problem I do see, that was not raised here is the MTOW of 97 tonnes with two wheel bogies, which will probably not allow this aircraft to have the short runway performance that the 757 had. I was wondering if Airbus would re-activate the 4 wheel bogie for this option as they had for the early A320s......


Surely runway performance is more a function of lift/thrust rather than wheel loading, or do you mean the 4 wheel bogie allows more tilt?
 
hudicourt
Posts: 5
Joined: Sun Feb 20, 2011 2:21 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Tue Nov 21, 2017 4:56 pm

kurtverbose wrote:
Surely runway performance is more a function of lift/thrust rather than wheel loading, or do you mean the 4 wheel bogie allows more tilt?


The 4 wheel bogie allows more wheels with brakes. Twice as many.

Commercial jets need to have "balanced field length" in order to take off from any runway. This means they must both have accelerate-stop and accelerate-go capability.

Accelerate-go involves being able to continue the take off after losing power on one engine after the decision speed (V1) .

Accelerates-stop involves aborting the take off and remain within the confines of the runway when losing power on one engine just before V1. Spoilers and reverse thrust help in stopping the aircraft in such cases but the brunt of the energy is absorbed by the aircraft brakes.

Same goes for landing. Although ample amounts of low speed lift allows an aircraft to land as slowly as possible, thus reducing the amount of runway required for stopping, again brakes are what absorb the most energy to stop the aircraft. Spoilers and Reverse Thrust contribute to stopping distance, but to a much lesser extent than brakes..
 
WIederling
Posts: 10043
Joined: Sun Sep 13, 2015 2:15 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Tue Nov 21, 2017 5:17 pm

hudicourt wrote:
kurtverbose wrote:
Surely runway performance is more a function of lift/thrust rather than wheel loading, or do you mean the 4 wheel bogie allows more tilt?


The 4 wheel bogie allows more wheels with brakes. Twice as many.


Braking performance is determined by wheel load and rubber/tire surface stiction coefficient.
you only get better braking if you brake a higher percentage of wheels. ( BUT a320 family is 4 of 4
and see planned increase of brakes installed on A380 MLG going from A388 to higher MTOW A389 or A38F )
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Mon Nov 27, 2017 9:18 am

WIederling wrote:
How much wingspan ( actually aspect ratio increase ) would an "A322"
( slightly longer than A321 ) need to cope well with the current 35k GTF engines?


The wing span would be determined by required lift, fuel capacity, the LDG configurations andperformance requirements.

A looked at fuel, increasing total by ~30% and getting rid of the ACT's for a base 4300NM version.

Image
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Thu Feb 01, 2018 10:09 am

WIederling wrote:
How much wingspan ( actually aspect ratio increase ) would an "A322"
( slightly longer than A321 ) need to cope well with the current 35k GTF engines?


Last year I looked at required fuel capacity / MTOW as a key driver for a larger wing and ended up with a ~ 4.5 bigger span, which would create a 20% higher wing surface and 30%+ higher wing fueltank capacity. A conservative approach assuming beefing up but not replacing the center wing box.

Image

Image
 
User avatar
acreinholz
Posts: 48
Joined: Sat Nov 18, 2017 5:28 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Thu Feb 01, 2018 1:17 pm

I know this is an old post, but i will always think economics and family of aircrafts... JetBlue (USA) and Azul (Brazil) share the same founder (Neeleman)... And both of them fly single aisle Airbuses (Yes, I know Azul also fly 6 A300s). Azul now uses its A330s to fly between VCP and CNF to FLL, MCO and LIS. The distance between VCP/FLL is around 4000MI (6500km). CNF/FLL is a little closer. Wouldn´t it be nice to Azul to be able to standardize its fleet? Also, Neeleman has acquired TAP and the distance between FLL/LIS is around 4100MI (6600km) and JFK/LIS even closer. Again, JetBlue does not belong to Neeleman anymore, but doesn´t he have a good relationship with its former company? Azul and JetBlue have a good agreement for operations and sharing flights already, it may also happen with TAP if JetBlue decides to fly from MIA and JFK to LIS. The A321LR is a good fit for this purpose. Yes, VCP/LIS and CNF/LIS are out of range but, for Azul and even TAP, the route REC/LIS is perfect for the A321LR and it releases TAP´s A330 fleet for other markets, such as Asia??? Huuummmm...

Summarizing:

Connecting the 3 major HUBs (VCP, FLL and LIS) with single aisle Airbus aircrafts. AZUL, JetBlue and TAP already focus on single aisle Airbus aircrafts. The A321LR seems to be the perfect fit...

I know it seems crazy... But they are all share the same Player (Neeleman)...

Please don´t be too nasty on the comments... Ahahahah
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Mon Jun 18, 2018 7:07 pm

acreinholz wrote:
I know this is an old post, but i will always think economics and family of aircrafts... JetBlue (USA) and Azul (Brazil) share the same founder (Neeleman)... And both of them fly single aisle Airbuses (Yes, I know Azul also fly 6 A300s). Azul now uses its A330s to fly between VCP and CNF to FLL, MCO and LIS. The distance between VCP/FLL is around 4000MI (6500km). CNF/FLL is a little closer. Wouldn´t it be nice to Azul to be able to standardize its fleet? Also, Neeleman has acquired TAP and the distance between FLL/LIS is around 4100MI (6600km) and JFK/LIS even closer. Again, JetBlue does not belong to Neeleman anymore, but doesn´t he have a good relationship with its former company? Azul and JetBlue have a good agreement for operations and sharing flights already, it may also happen with TAP if JetBlue decides to fly from MIA and JFK to LIS. The A321LR is a good fit for this purpose. Yes, VCP/LIS and CNF/LIS are out of range but, for Azul and even TAP, the route REC/LIS is perfect for the A321LR and it releases TAP´s A330 fleet for other markets, such as Asia??? Huuummmm...

Summarizing:

Connecting the 3 major HUBs (VCP, FLL and LIS) with single aisle Airbus aircrafts. AZUL, JetBlue and TAP already focus on single aisle Airbus aircrafts. The A321LR seems to be the perfect fit...

I know it seems crazy... But they are all share the same Player (Neeleman)...

Please don´t be too nasty on the comments... Ahahahah


Highly unlikely. However Neeleman seems on a creation plan again and Airbus is looking for more payload-range..
https://www.cnbc.com/2018/06/18/jetblue-founder-reportedly-preparing-to-launch-new-low-cost-airline.html
 
strfyr51
Posts: 6044
Joined: Tue Apr 10, 2012 5:04 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Mon Jun 18, 2018 9:36 pm

WPvsMW wrote:
keesje's points are about various stage profiles, but mostly about long haul compromises in the A321 design. I drew the inference that the B757 is better suited for long-haul, putting aside fuel consumption. Thus... the MOM as A321-killer. Now, that statement lacks all controversy. :D :D ;)


I seriously doubt Boeing designed the MoM airplane to damage the A321. Airbus is trying to present the A321 to dissuade Boeing from Launching the MoM airplane which will be futile since they'll have no direct alternative. Now? Should Boeing revamp the B757?? Airbus might have a shot !
But those airlines who might buy 100+ airframes?? Airbus might be hard pressed if Boeing ups the performance of the B757 replacement since the A321 is even hard pressed to equal an OLD B757 in performance..
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Mon Jun 18, 2018 11:09 pm

strfyr51 wrote:
WPvsMW wrote:
keesje's points are about various stage profiles, but mostly about long haul compromises in the A321 design. I drew the inference that the B757 is better suited for long-haul, putting aside fuel consumption. Thus... the MOM as A321-killer. Now, that statement lacks all controversy. :D :D ;)


I seriously doubt Boeing designed the MoM airplane to damage the A321. Airbus is trying to present the A321 to dissuade Boeing from Launching the MoM airplane which will be futile since they'll have no direct alternative. Now? Should Boeing revamp the B757?? Airbus might have a shot !
But those airlines who might buy 100+ airframes?? Airbus might be hard pressed if Boeing ups the performance of the B757 replacement since the A321 is even hard pressed to equal an OLD B757 in performance..


I heard it is nearly 30% cheaper to fly an A321NEO than an 757.
 
WIederling
Posts: 10043
Joined: Sun Sep 13, 2015 2:15 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Tue Jun 19, 2018 10:31 am

keesje wrote:
I heard it is nearly 30% cheaper to fly an A321NEO than an 757.

Pfffft. Just NEO the 757 to retain its throne.
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Wed Jun 20, 2018 8:07 pm

WIederling wrote:
How much wingspan ( actually aspect ratio increase ) would an "A322"
( slightly longer than A321 ) need to cope well with the current 35k GTF engines?


For a similar shaped wing a ~10% bigger span would create a ~20% lower wing loading and ~30% more wing tank fuel capacity. However that means a new wing, which would have a different modern design optimized for longer range and higher speed.

Image
 
WIederling
Posts: 10043
Joined: Sun Sep 13, 2015 2:15 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Thu Jun 21, 2018 7:34 am

keesje wrote:
For a similar shaped wing a ~10% bigger span would create a ~20% lower wing loading and ~30% more wing tank fuel capacity. However that means a new wing, which would have a different modern design optimized for longer range and higher speed.

https://lh3.googleusercontent.com/-_j4C ... MA%2B3.jpg


How much do I have to increase AR to have such a bigger plane cope with the (upper limit?) 35k thrust GTF engine derivative.
 
A380MSN004
Posts: 852
Joined: Sat Jun 03, 2017 9:07 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Thu Jun 21, 2018 10:03 pm

hudicourt wrote:
1)
One problem I do see, that was not raised here is the MTOW of 97 tonnes with two wheel bogies, which will probably not allow this aircraft to have the short runway performance that the 757 had. I was wondering if Airbus would re-activate the 4 wheel bogie for this option as they had for the early A320s......


Does someone can tell the takeoff distance at 97T for the 321 NEO/LR ?
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Tue Sep 04, 2018 8:34 am

WIederling wrote:
How much wingspan ( actually aspect ratio increase ) would an "A322"
( slightly longer than A321 ) need to cope well with the current 35k GTF engines?


I assumed a ~10% bigger wingspan, based on required wing fuel volume (+30%) and more optimal wing loading.

Image

What has become clear though is that Airbus very much wants to stick to current wings / gate compatibility, understandably. If they have to go for a bigger wingspan, maybe there is extra space (until the next IATA gate enveloppe limitation) to do a real optimal wing, making able to do a significant longer / heavier NB with the required 4500NM range.

Anyway it seems the "Operational Weak Spots of the Airbus A321NEO/LR" have landed by airlines in TLS, hence their new A321XLR study. No doubt bumping the wing / fuel / operational / performance limitations listed above.

Image
 
User avatar
MoKa777
Posts: 1213
Joined: Fri Oct 21, 2016 11:47 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Sat Sep 08, 2018 5:41 pm

How will the A321neoLR cope in a place like KWI where summer temperatures are 45-50°C?
 
User avatar
lightsaber
Moderator
Posts: 24641
Joined: Wed Jan 19, 2005 10:55 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Mon Sep 10, 2018 3:14 pm

keesje wrote:
WIederling wrote:
How much wingspan ( actually aspect ratio increase ) would an "A322"
( slightly longer than A321 ) need to cope well with the current 35k GTF engines?


I assumed a ~10% bigger wingspan, based on required wing fuel volume (+30%) and more optimal wing loading.

Image

What has become clear though is that Airbus very much wants to stick to current wings / gate compatibility, understandably. If they have to go for a bigger wingspan, maybe there is extra space (until the next IATA gate enveloppe limitation) to do a real optimal wing, making able to do a significant longer / heavier NB with the required 4500NM range.

Anyway it seems the "Operational Weak Spots of the Airbus A321NEO/LR" have landed by airlines in TLS, hence their new A321XLR study. No doubt bumping the wing / fuel / operational / performance limitations listed above.

Image

A new wing is a multi billion effort. I see no reason it wouldn't be CFRP. Due to demand for fitting in 738 gates, it would probably have folding wingtips, so added fuel +10%, not +30%. The empty weight would be about the same, maybe 1t less.

I would pair it with 787-10 like gear to improve takeoff, so stretch the cabin by 60" or so for 10 more seats (not for long haul).

And yes, lighten the ACTs... Past due for a complete redesign.

However, the MoM will have modern subsystems (they save about 3% in fuel) and higher bypass engines designed for CMC turbine blades. At some point, only new is competitive.

Also, a higher cruise altitude would be desired which is a fatigue issues and requires a new cabin pressurization.

Lightsaber
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Mon Sep 10, 2018 4:06 pm

lightsaber wrote:
keesje wrote:
WIederling wrote:
How much wingspan ( actually aspect ratio increase ) would an "A322"
( slightly longer than A321 ) need to cope well with the current 35k GTF engines?


I assumed a ~10% bigger wingspan, based on required wing fuel volume (+30%) and more optimal wing loading.

Image

What has become clear though is that Airbus very much wants to stick to current wings / gate compatibility, understandably. If they have to go for a bigger wingspan, maybe there is extra space (until the next IATA gate enveloppe limitation) to do a real optimal wing, making able to do a significant longer / heavier NB with the required 4500NM range.

Anyway it seems the "Operational Weak Spots of the Airbus A321NEO/LR" have landed by airlines in TLS, hence their new A321XLR study. No doubt bumping the wing / fuel / operational / performance limitations listed above.

Image

A new wing is a multi billion effort. I see no reason it wouldn't be CFRP. Due to demand for fitting in 738 gates, it would probably have folding wingtips, so added fuel +10%, not +30%. The empty weight would be about the same, maybe 1t less.

I would pair it with 787-10 like gear to improve takeoff, so stretch the cabin by 60" or so for 10 more seats (not for long haul).

And yes, lighten the ACTs... Past due for a complete redesign.

However, the MoM will have modern subsystems (they save about 3% in fuel) and higher bypass engines designed for CMC turbine blades. At some point, only new is competitive.

Also, a higher cruise altitude would be desired which is a fatigue issues and requires a new cabin pressurization.

Lightsaber


You are correct Lightsaber, lots of things that could be improved.

What I find interesting though, is the weight (symbolic) Airbus gives to maintain maximum commonality with the existing customer base and supply chain. Plus ensuring short time to market.

Airbus apparently is accepting significant sub optimization to keep commonality as close as possible to the base A320 and capture a big share of the market before Boeing can respond. I think if Boeing was focussing on a NSA design iso 737-9/10MAX and big NMA, they would be working on a composites wing. Which they haven't shelved, they're just keeping quiet. Now and then there is a slip of the tongue confirming this. (there's always involved, deeply enthousiast engineers crossing the line :biggrin: )
 
User avatar
lightsaber
Moderator
Posts: 24641
Joined: Wed Jan 19, 2005 10:55 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Tue Sep 11, 2018 2:44 pm

keesje wrote:
lightsaber wrote:
keesje wrote:

I assumed a ~10% bigger wingspan, based on required wing fuel volume (+30%) and more optimal wing loading.

Image

What has become clear though is that Airbus very much wants to stick to current wings / gate compatibility, understandably. If they have to go for a bigger wingspan, maybe there is extra space (until the next IATA gate enveloppe limitation) to do a real optimal wing, making able to do a significant longer / heavier NB with the required 4500NM range.

Anyway it seems the "Operational Weak Spots of the Airbus A321NEO/LR" have landed by airlines in TLS, hence their new A321XLR study. No doubt bumping the wing / fuel / operational / performance limitations listed above.

Image

A new wing is a multi billion effort. I see no reason it wouldn't be CFRP. Due to demand for fitting in 738 gates, it would probably have folding wingtips, so added fuel +10%, not +30%. The empty weight would be about the same, maybe 1t less.

I would pair it with 787-10 like gear to improve takeoff, so stretch the cabin by 60" or so for 10 more seats (not for long haul).

And yes, lighten the ACTs... Past due for a complete redesign.

However, the MoM will have modern subsystems (they save about 3% in fuel) and higher bypass engines designed for CMC turbine blades. At some point, only new is competitive.

Also, a higher cruise altitude would be desired which is a fatigue issues and requires a new cabin pressurization.

Lightsaber


You are correct Lightsaber, lots of things that could be improved.

What I find interesting though, is the weight (symbolic) Airbus gives to maintain maximum commonality with the existing customer base and supply chain. Plus ensuring short time to market.

Airbus apparently is accepting significant sub optimization to keep commonality as close as possible to the base A320 and capture a big share of the market before Boeing can respond. I think if Boeing was focussing on a NSA design iso 737-9/10MAX and big NMA, they would be working on a composites wing. Which they haven't shelved, they're just keeping quiet. Now and then there is a slip of the tongue confirming this. (there's always involved, deeply enthousiast engineers crossing the line :biggrin: )

Sub optimization works until it doesn't, see MD-90.

Once the A220 is out in numbers, we will have more evidence of the benefits of the technology I posted.
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Fri Nov 16, 2018 4:01 pm

keesje wrote:
While the A321NEO has been selling well over the last couple of years, there are obviously some weak spots on the LR from an airline perspective.

1. Range. TATL is being promoted but the 4000NM clean/still air range proved short for the 757 under real conditions. Why would the A321LR do any better?
2. Longer flights mostly require crew rests for cockpit & cabin crew. Limited options seem available without cutting passenger seat capacity.
3. Early stage cruise performance: the limited wing area limits early cruise levels, leading to sub optimal fuel consumption
4. Luggage space. With the 2 ACT's required for longer flights, available space for luggage / cargo seems low. specially with >200 passengers.
5. Cruise speed. Mach 0.78 is a kind of low for 4-7 hr flights. hurting utilization. E.g. a 787 is 10% faster.
6. Cargo: longer flights are dominated by containerized full LD3 / pallets. An A321 can't take them.
7. Capacity, with todays sleeper seats & premium economy cabins required for medium flight commonality, capacity seems limited to 150-170 seats, low for 5-7 hr flights.
8. Limited future growth perspective when buying A321LR's. No family concept / future growth option.



Apparently Airbus themselves sees the operational weakspots (or the airlines do) because they are pushing/pulling..

https://www.flightglobal.com/news/articles/airbus-indicates-a321xlr-would-have-over-100t-mtow-453590/

Of the weak spots identified,

1. range would be ~solved if they manage to increase it to 4500Nm or above.
3. early stage cruise performance &
4. luggage space would still be critical.
8. family potential (stretch) could be there, based on a 100t MTOW. Maybe the intention of this mod is to have 2 versions?

tbc..
 
parapente
Posts: 3061
Joined: Tue Mar 28, 2006 10:42 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Mon Nov 19, 2018 11:54 am

The A321neo LR (3act's) and XLR built in additional tanks does not really effect what Boeing are proposing with their 797 mom.Theirs is a 220-270 two class seating low/Midrange model using the larger twin aisle format.They are not imho really competitors.
There are really no good existing comparisons to either aircaft.
But the 797 seems far better equipt to replace 767's and 332's,particularly the latter if the range and lifting capabilities are not required.
The 321LR/XLR appears to be effectively a Midrange 200 odd seater with very little cargo capacity.This doesn't make it better or worse ,just different.
 
tealnz
Posts: 724
Joined: Mon Nov 09, 2015 10:47 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Mon Nov 19, 2018 3:19 pm

keesje wrote:
Of the weak spots identified,

1. range would be ~solved if they manage to increase it to 4500Nm or above.
3. early stage cruise performance &
4. luggage space would still be critical.
8. family potential (stretch) could be there, based on a 100t MTOW. Maybe the intention of this mod is to have 2 versions?

From what we know of the XLR configuration the new integral aft hold tank would carry the equivalent of four ACTs in the space currently occupied by two ACTs plus a void behind the undercarriage bay. That means the forward hold plus three LD3-45 spaces in the aft hold would be available for baggage. Should be sufficient for the likely XLR passenger configurations.
 
BREECH
Posts: 663
Joined: Tue Jun 30, 2009 3:20 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Mon Nov 19, 2018 4:39 pm

keesje wrote:
2. Longer flights mostly require crew rests for cockpit & cabin crew. Limited options seem available without cutting passenger seat capacity.

It's absolutely amazing what a person can do when he's bored.
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Tue Dec 25, 2018 4:24 pm

keesje wrote:
While the A321NEO has been selling well over the last couple of years, there are obviously some weak spots on the LR from an airline perspective.
1. Range. TATL is being promoted but the 4000NM clean/still air range proved short for the 757 under real conditions. Why would the A321LR do any better?
2. Longer flights mostly require crew rests for cockpit & cabin crew. Limited options seem available without cutting passenger seat capacity.
3. Early stage cruise performance: the limited wing area limits early cruise levels, leading to sub optimal fuel consumption.
4. Luggage space. With the 2 ACT's required for longer flights, available space for luggage / cargo seems low. specially with >200 passengers.
5. Cruise speed. Mach 0.78 is a kind of low for 4-7 hr flights. hurting utilization. E.g. a 787 is 10% faster.
6. Cargo: longer flights are dominated by containerized full LD3 / pallets. An A321 can't take them.
7. Capacity, with todays sleeper seats & premium economy cabins required for medium flight commonality, capacity seems limited to 150-170 seats, low for 5-7 hr flights.
8. Limited future growth perspective when buying A321LR's. No family concept / future growth option.

Image

The A321LR is more efficient than the 35 yr old 757, congratulations. But apart from that.. Maybe the A321LR is the best Airbus can do right now, but there's seems definitely room for improvement. :coffee:


In the previous 18 months Airbus has innitiated serious efforts to neutralize some of the Operational Weak Spots of the Airbus A321NEO/LR.

1. ++ Range. If Airbus manages to secure 4700NM with sufficient payload, that seems covered.

2. -/+ Crew rest can be realized at the cost of passenger capacity.

3. - Early stage cruise. With an 101t MTOW, this remains a serious restriction. Wing optimization still seems desirable.

4. + Airbus seems to work on efficient fuel tanks. For medium range 2-3 class cabins 6 AKH worth of space seems enough.

5. - Cruise speed seems low, significant wing mods would be required to increase this.

6. -/+ Lack of cargo capability seems a price to be paid for a A321 medium range operation.

7. - Low capacity seems hard to solve, a stretch would eat into range.

8. + The XLR's MTOW growth of 4t could offer acceptable capacity for range Airbus, as studied 20 yrs ago.

Image

All in all I wonder what wing improvements could be done without compromizing commonality too much.
 
tealnz
Posts: 724
Joined: Mon Nov 09, 2015 10:47 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Tue Dec 25, 2018 4:57 pm

On early-stage cruise and future growth, Leeham reported that Airbus are looking at a new split wingtip for the XLR. Sounds as if this would be the interim fix.

Clearly the longer-term answer is a new longer CFRP wing with more integral fuel and higher cruise mach capability. Airbus officials in UK this year said that a 40-44m wing is being developed to go into production within a decade. That also opens the way to a stretch with more than trans-continental range. But not in the short term.
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Thu Jun 06, 2019 1:07 pm

tealnz wrote:
On early-stage cruise and future growth, Leeham reported that Airbus are looking at a new split wingtip for the XLR. Sounds as if this would be the interim fix.

Clearly the longer-term answer is a new longer CFRP wing with more integral fuel and higher cruise mach capability. Airbus officials in UK this year said that a 40-44m wing is being developed to go into production within a decade. That also opens the way to a stretch with more than trans-continental range. But not in the short term.


Looking back at the opening posts 2 years back, Airbus has been chipping away LR weaknesses that were identified.
The MTOW bump of 4t & better tanks vastly improving flexibility / operational reliability.

I'm curious to see if / how they improve the A321LR wing, without compromising A321 commonality too much..
A time line of 2023-24 is now mentioned. Assume Airbus started putting in serious engineering efforts a year ago, that gives them 4-5 years.

That's enough to do more than just beefing up structure.. We have seen wing mods using variable camber, slat, flap, OAO tilting, laminair, wingtip devices and adjustments in the FBW flight control setting.

Image

If no wing mods are made, V1 would rise a bit, which could be compensated by a slight thrust bump on the engines (for no growth in runway lenght).
 
flipdewaf
Posts: 5307
Joined: Thu Jul 20, 2006 6:28 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Thu Jun 06, 2019 2:53 pm

Keesje, if you keep resurrecting dead threads like this you will find yourself as the focal point of a religion!

Whilst I agree with the technical parts of what you have written with regards to Airbus putting a larger wing on the A32X series in terms of performace (range, field length etc) the biggest challenge and risk airbus face with this is how to they integrate this in to the supply and manf. chain without causing discontinuity in parts and work routines and how this affects the low costs associated with the relatively high level of production.

Keesje: do you work for a company with links to the aerospace industry?

Fred
 
tealnz
Posts: 724
Joined: Mon Nov 09, 2015 10:47 am

Re: Operational Weak Spots of the Airbus A321NEO/LR Discussion Thread

Thu Jun 06, 2019 5:33 pm

The XLR will be a good test of Airbus’s ability to make incremental improvements without disrupting production, sales or commonality for operators. Wing improvements are one or several big unanswered questions. Just a MAX-style wingtip treatment? Or something more substantial? We haven’t really had any good clues so far apart from the Leeham reference.
 
Armadillo1
Posts: 647
Joined: Thu Apr 20, 2017 5:14 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Fri Jun 07, 2019 7:42 am

hudicourt wrote:
In any case, such an aircraft, when used for TransAtlantic flights, will only do one round trip per day. No more. A six hour leg eastbound, a seven hour westbound leg and two two hour turnarounds add up to 17 hours. That leaves just 7 hours in the day, not enough for more than a couple short haul legs.

how airlines planned schedule? 1-day basis only? no week or 2-3 days basic (2/3 day for one leg, 1/2 for second, 2/3 for 3rd leg for example)?
 
448205
Posts: 2323
Joined: Mon May 02, 2016 4:55 am

Re: Operational Weak Spots of the Airbus A321NEO/LR Discussion Thread

Fri Jun 07, 2019 3:17 pm

The wing is simply the biggest limitation for this airplane. When it was designed, the A320 weighed 155,000lbs. 58,000lbs less than the 213k of today.
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR Discussion Thread

Wed Jun 12, 2019 12:38 pm

tealnz wrote:
The XLR will be a good test of Airbus’s ability to make incremental improvements without disrupting production, sales or commonality for operators. Wing improvements are one or several big unanswered questions. Just a MAX-style wingtip treatment? Or something more substantial? We haven’t really had any good clues so far apart from the Leeham reference.


I think nothing has been communicated about possible wing changes / improvements for the XLR. If I have time left next week I'll ask around / keep my eyes open. I thought it would be just beefing up structure & live with the compromises. But now 2024 EIS has been mentioned, I'm not sure anymore.. even a moderate cord extension would do wonders for fuel capacity & wing loading. But it is ~ a new wing..

Image
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR Discussion Thread

Fri Jun 21, 2019 7:55 pm

Has any sketch / drawing / cutaway been published on the new A321XLR fuel tank configuration?
 
astuteman
Posts: 7942
Joined: Mon Jan 24, 2005 7:50 pm

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Sat Jun 22, 2019 6:39 am

A380MSN004 wrote:
hudicourt wrote:
1)
One problem I do see, that was not raised here is the MTOW of 97 tonnes with two wheel bogies, which will probably not allow this aircraft to have the short runway performance that the 757 had. I was wondering if Airbus would re-activate the 4 wheel bogie for this option as they had for the early A320s......


Does someone can tell the takeoff distance at 97T for the 321 NEO/LR ?


The February 2019 A321 ACAP now contains the field performance (or take off and landing limitations) for the A321LR

It shows the field length at 0 ft and ISA conditions to be about 8 300ft at 97 tonnes.
Conveniently, the graph goes up to 100 tonnes, at which weight the field length is 9 000ft.
Given the flap modifications made, I would expect the 101t A321 XLR to be about the same as the 100t LR

keesje wrote:
I think nothing has been communicated about possible wing changes / improvements for the XLR. If I have time left next week I'll ask around / keep my eyes open. I thought it would be just beefing up structure & live with the compromises. But now 2024 EIS has been mentioned, I'm not sure anymore.. even a moderate cord extension would do wonders for fuel capacity & wing loading. But it is ~ a new wing..


Of course we know now that something HAS been communicated about possible wing changes / improvements for the XLR

https://www.flightglobal.com/news/artic ... ig-459156/

"Our [computational fluid dynamics] capabilities have improved a lot since the 1980s so we've been able to design a single-slotted flap that's as efficient as a double-slotted design and gives a similar kind of performance globally, because it also saves some weight."
He adds: "For take-off especially, we're reducing drag in the second-segment climb."
Another new feature being introduced on the XLR's flap system is the ability to set the surfaces at intermediate positions, depending on operating conditions.


Cheaper, lighter, simpler, and more effective.

Rgds
 
User avatar
keesje
Topic Author
Posts: 15156
Joined: Thu Apr 12, 2001 2:08 am

Re: Operational Weak Spots of the Airbus A321NEO/LR.

Sun Jun 23, 2019 10:30 am

astuteman wrote:
A380MSN004 wrote:
hudicourt wrote:
1)
One problem I do see, that was not raised here is the MTOW of 97 tonnes with two wheel bogies, which will probably not allow this aircraft to have the short runway performance that the 757 had. I was wondering if Airbus would re-activate the 4 wheel bogie for this option as they had for the early A320s......


Does someone can tell the takeoff distance at 97T for the 321 NEO/LR ?


The February 2019 A321 ACAP now contains the field performance (or take off and landing limitations) for the A321LR

It shows the field length at 0 ft and ISA conditions to be about 8 300ft at 97 tonnes.
Conveniently, the graph goes up to 100 tonnes, at which weight the field length is 9 000ft.
Given the flap modifications made, I would expect the 101t A321 XLR to be about the same as the 100t LR

keesje wrote:
I think nothing has been communicated about possible wing changes / improvements for the XLR. If I have time left next week I'll ask around / keep my eyes open. I thought it would be just beefing up structure & live with the compromises. But now 2024 EIS has been mentioned, I'm not sure anymore.. even a moderate cord extension would do wonders for fuel capacity & wing loading. But it is ~ a new wing..


Of course we know now that something HAS been communicated about possible wing changes / improvements for the XLR

https://www.flightglobal.com/news/artic ... ig-459156/

"Our [computational fluid dynamics] capabilities have improved a lot since the 1980s so we've been able to design a single-slotted flap that's as efficient as a double-slotted design and gives a similar kind of performance globally, because it also saves some weight."
He adds: "For take-off especially, we're reducing drag in the second-segment climb."
Another new feature being introduced on the XLR's flap system is the ability to set the surfaces at intermediate positions, depending on operating conditions.


Cheaper, lighter, simpler, and more effective.

Rgds


Hi Astute, indeed. You can see Airbus has choosen to keep the basic wing as standard as possible, working on the edges. It will be interesting to see how the new flaps look. I guess they'll be larger than the NEO's and the flap .5, 1.5 area will be used to lower wingloading during extended flight stages. Maybe they'll do a similar review / mod of the slats too. CFD might provide new insights over this eighties design.

Image

Equally, I wouldn't consider the current Sharklets fixed for the XLR yet. I can see a lot of pulling and pushing going in labs, windtunnels and design offices as we speak.
 
User avatar
TheRedBaron
Posts: 3282
Joined: Tue Mar 29, 2005 6:17 am

Re: Operational Weak Spots of the Airbus A321NEO/LR Discussion Thread

Tue Jun 25, 2019 10:46 pm

Varsity1 wrote:
The wing is simply the biggest limitation for this airplane. When it was designed, the A320 weighed 155,000lbs. 58,000lbs less than the 213k of today.


Correct, as I have read Airbus is trying to bring down empty weight , and simplifying the wing using variable angle flaps and multi position Slats.... and making them as efficient as possible (with the current geometry) to allow a much better lift/drag/weight/ I am curious as how much the A350 wing and winglets will layout in these modifications.

Regards

TRB
 
Max Q
Posts: 10240
Joined: Wed May 09, 2001 12:40 pm

Is the A321LR done already ?

Wed Jun 26, 2019 10:06 pm

With the recent launch of the significantly
more capable A321XLR it seems doubtful
there will be any more customers for the
‘regular’ LR version


Several airlines have already converted existing LR orders to the XLR model


I’m thinking the LR will join the ranks of
the 747SP, 767-400, 737-900, as far as popularity and total orders
 
Vladex
Posts: 544
Joined: Sat Oct 26, 2013 2:44 pm

Re: Is the A321LR done already ?

Wed Jun 26, 2019 10:13 pm

there would be no XLR without LR so it's a moot point
 
Max Q
Posts: 10240
Joined: Wed May 09, 2001 12:40 pm

Re: Is the A321LR done already ?

Wed Jun 26, 2019 10:19 pm

Vladex wrote:
there would be no XLR without LR so it's a moot point



Not at all, that’s not the question
 
User avatar
ikolkyo
Posts: 4460
Joined: Tue Nov 05, 2013 8:43 pm

Re: Is the A321LR done already ?

Wed Jun 26, 2019 10:23 pm

Eh, the LR is really just an MTOW bump over a regular A321NX. Not a good comparison to the 764 and etc. It will probably live on as a 97t weight option.
 
User avatar
enilria
Posts: 10410
Joined: Fri Feb 22, 2008 7:15 pm

Re: Is the A321LR done already ?

Wed Jun 26, 2019 10:42 pm

ikolkyo wrote:
Eh, the LR is really just an MTOW bump over a regular A321NX. Not a good comparison to the 764 and etc. It will probably live on as a 97t weight option.

I was about to say the same thing. This doesn’t hurt Airbus at all. What it hurts is resale value on the 321LR for airlines that bought. Whatever the upsell was is probably completely lost.
 
VSMUT
Posts: 5496
Joined: Mon Aug 08, 2016 11:40 am

Re: Is the A321LR done already ?

Wed Jun 26, 2019 10:52 pm

IMO, it will still be an A321 capable of TATL flights, so will remain extremely capable and valuable. It will inevitably be cheaper than the XLR, but still more capable than the baseline 321neo. That alone will place it in valuable niche.

Max Q wrote:

Several airlines have already converted existing LR orders to the XLR model


Which airlines?
 
KFLLCFII
Posts: 3666
Joined: Sat Sep 11, 2004 7:08 am

Re: Is the A321LR done already ?

Wed Jun 26, 2019 11:31 pm

Max Q wrote:
With the recent launch of the significantly
more capable A321XLR it seems doubtful
there will be any more customers for the
‘regular’ LR version


Several airlines have already converted existing LR orders to the XLR model


I’m thinking the LR will join the ranks of
the 747SP, 767-400, 737-900, as far as popularity and total orders


And the XLR will join the same ranks after the XXLR is offered for sale.
 
RJMAZ
Posts: 3573
Joined: Sat Jul 09, 2016 2:54 am

Re: Is the A321LR done already ?

Thu Jun 27, 2019 4:57 am

I expect the A321XLR to become the only A321 model produced in about 5 years time

However the A321XLR will be derated to different MTOW's which Airbus often does. The names will probably live on to represent the different MTOW's.

93T A321
97T A321LR
101T A321XLR

The engines will probably be derated to provide lower servicing costs and greater time between overhauls. There will be a decent price increase between the models.

Most A321's have been flying with one ACT for the last decade or two. A large percentage have been flying with two ACT's. So the larger fuel tank in the A321XLR will work great even though the lowest 93T MTOW version will probably not be able to fill the tank right up with a normal payload.

Who is online

Users browsing this forum: gregorygoodwin, planecane and 29 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos