15 Jan 2015: Airbus officially launched what to date has been called A321neoLR as the A321LR at their annual press conference Tuesday. The former A321neoLR name was formed by Leeham News on 21 Ocober 2014 when we could reveal the existence of a A321neo variant which Airbus had started to present to airlines at the time. The final name kept the LR attribute used in the article to distinguish the longer range variant from the standard A321neo.
The A319 has used the LR designation but its use has been limited. The suffix is more commonly identified with Boeing, used as it is with the 777-200LR. Boeing has also commonly used the ER for extended range like 777-200ER, 737-900ER and 777-300ER.
Airbus has traditionally not given more capable versions a special suffix, the aircraft has been named A330-300 in their 3000nm version as well as 6000nm. Sometimes one has seen an unofficial HGW for Higher Gross Weight or A340-300E for Enhanced but not ER or typically LR. The A321LR is a 97t version intended to brand an aircraft variant that takes on the Boeing 757.
What is in the LR?
To understand what is behind the LR suffix, we will go through the process of adding range to an A321neo just like Airbus did. We will use our proprietary model to change parameters and see the results. This will brings us in steps to the final specification for the A321LR. It is a bit more involved than just adding fuel but we will take it in steps and when through we have also experienced what Airbus has been through over the years as they have gradually extended the capabilities of the A320 range and what airlines discuss with them when they sit down to understand if A321LR is something for them.
Extending the range of A321neo
A standard A321, whether it is ceo (current engine option), or neo (new engine option), is limited in range at just about any cabin and passenger combination by its internal fuel capacity (all in the wings). If we use the OEM “show room” or brochure cabin configuration of 185 seats divided over 16 premium seats (short haul first class recliners at 36 inch pitch) and 169 economy seats (standard economy at 32 inch pitch) and the highest standard weight variant at 93.5t, then A321neo would have a range of 3000nm. A321neo press releases and presentations says 3600nm but there is a caveat in there which is called extra tanks.
Here is how it works
When we have loaded our 185 passengers on the 93.5t A321neo, we fill the wings with fuel for our trip. At 86t, the fuel guy comes onto the intercom and says “tanks are full.” We look at our load-sheet and see we have a whopping 7.5t still to our Max TakeOff Weight (MTOW). We have a fully booked flight (185 pax + bags payload at the OEM standard weight of 16.7t) so we can’t add any more passengers but ideally we would have wanted to add more payload in the form of cargo. As our 2700nm flight due to headwinds needs the 3000nm range we can’t take cargo even though the passenger bags have only taken eight of our 10 LD3-45 positions. We need to fly the aircraft at 86t to get the 3000nm still air range for the day. This is called that the aircraft is fuel limited, i.e., the tank volume limits its use at high payloads and long range.
The way to extend the range of our A321neo is then to add fuel tankage in the form of “Additional Center Tank” or ACTs in the cargo bays. Each of these tanks take the place of an LD3-45 and adds 2990l or 2.4t of fuel.
So let’s assume that we need to fly our A321neo a bit longer. To do that, we add one ACT in the rear cargo hold. The first thing that happens is that our empty weight increases with 0.6t. The ACT only weights 0.4t each but the base installation kit with plumbing, pumps, safety fire wall, etc., takes another 200kg. This extra weight carves into our useful payload (passengers + cargo) on shorter haul so we would only do this modification if the aircraft would be used a lot for long haul at up to the range limit. On long hauls, we know we reach fuel before weight limits so we can add the tank without weight worries.
For the same flight our tanks would now be full at 88.8t, so the aircraft is still fuel limited but now has a range of 3400nm. We can now take on longer destinations or we can trade fuel for more payload. The only problem is that we now have only one cargo position left after passenger bags are loaded. Typically one LD3-45 position adds 0.5t cargo, so there is no large extra revenue source from cargo in this case.
Should we want to fly even longer we add another tank and we would have our limits at 91.5t and 3800nm, still fuel limited at two ACTs in an OEM “show room” spec. case.
Actual airline cabins leads to A321LR
Everyone who has bought a car and looked at the brochure weight and then weighed the delivered car knows there is a large difference between the figures. Airplanes are no different. The example above assumes an OEM standard cabin with typical short range premium seats, very basic galley and entertainment equipment and no optional equipment like extra avionics or on-board WiFi internet. With such a configuration the A321neo empty weight is just above 50t. Depending on the airline this will increase to close to 55t in a real case when premium seating, modern IFE, WiFi and catering equipment is included with other aircraft options. This means the above discussion gets pushed up four tonnes and we start to hit our MTOW limit before we have the fuel guy telling us the tanks are full, our aircraft is now weight limited.
This is what Airbus has been working on with the airlines since the summer. They knew they had to get a realistically configured A321neo to fly minimum 3500nm reliably to take on long range 757-200 missions. To do that they needed to fly still air distances of around 4000nm with 15-18t of passengers (160-200 passengers with bags) and still have room for 25t of fuel in the aircraft to get flight times of 8 to 9 hours. This all adds up to a max takeoff weight of 80t plus payload, and 95-98t MTOW is needed.
With our trip through the realities of the Airbus A321neo, we have learned the different trades that have to be considered for an airline that buys a A321LR for Trans-Atlantic missions. A big influence will be the cabin and optional equipments choices. Airbus advertises the A321LR at launch as 16 business class (36 inch pitch) and 190 economy (30 inch pitch) for a total of 206 seats. Our model shows that the empty weight of the A321LR has to stay below 52t for this to work, so Airbus assumes a typical “OEM show room” configuration with very basic assumptions for seat weights, IFE, galley equipment, aircraft options, quite different from the typical Boeing 757-200W configurations we compared with from Delta Air Lines and United Airlines in October.
We can also see that Airbus has assumed non LD3-45 loaded passenger bags. The bags simply does not fit for 206 passengers in a containerized concept with normal assumptions for bags per passenger and bags per container. It requires nine containers free and we would only have seven after the three fuel tanks have been installed. With bulk-loaded bags, including using the bulk cargo area, the bags for 206 passengers will fit with a bit of room to spare.
By using our model we have reproduced some of the iterations that Airbus design group has gone through to reached the base specification for A321LR. We now also know the trades there are when weighing things like premium business seats (which weigh as much as three times the premium seats assumed by Airbus in the base specification) versus economy seats, versus extra tanks and what has to be considered for cargo + bags storage concepts. This round robin optimization discussion is nothing unique for the A321LR. This is the practical process for any configuration of an airliner.
In the end, both examples of configurations that has been discussed are realistic, typical mainline carriers would tend towards our October examples (162 seats in lie flat business; premium and standard economy) whereas low cost carriers might tend more towards Airbus launch example.
Finally, Boeing on Tuesday tried to make the case that Airbus is merely “catching up” to the 737-9. As our previous analyses have shown, the 737-9 is inferior to the A321neo and then-proposed A321neoLR for long range stretching.
Boeing on Tuesday said a 737-9 BBJ with three additional tanks has a range of 6,000 nautical miles. This shows how disturbed Boeing is by the fact that Airbus could cover a large part of the segment they had identified as a starting point for their next generation small airplane with a further refinement of an existing A320. The issue is of course airliner-to-airliner, not BBJ-to-airliner. In the former, Airbus has the advantage, and sales figures bear this out: the A321neo is outselling the 737-9 by a ratio of 2.6:1.
an excellent presentation and synopsis.
As a next step I’d like some information into engine requirements and the expected solution. does the 35klbs GTF engine cover the increased thrust demand for keeping acceptable runway performance?
it was all covered in our October article series, we deduced all important requirements on a 757-200 replacement and then applied them to A321neo and 737 MAX 9, out came the spec for A321neoLR. Airbus then confirmed they were working on such a variant, Boeing did not as the MAX 9 is limited in its takeoff regime by rotation limitations. The runway performance of an A321neoLR is no worse then many other operational airliners. There are two main parameters which govern takeoff performance, wing-loading (lift required at takeoff over wing area) and power-loading (takeoff thrust over takeoff mass). As an example the A321LR is better than the 777-300ER in both respects (all in the articles).
Re engines; A321LR is available with both A321neo engines and in the base spec they have the same capabilities. Pratt & Whitney (PW) has announced improvements coming up for 2019 when the A321LR will start deliveries. The thrust bump to 35klbf is not without caveats to our knowledge, lets see what it really entails before drawing to many conclusions.
CFM is about 6-9 months behind in the development of LEAP-1A for A320, they will most likely follow PW with any improvement announcements but probably don’t want to before having more flight test data on their engines (-1A flew for first time just before Christmas on GE’s 747).
In any case the base 33klbf specification is fully adequate to give the A321LR the start performance it need for normal airliner operation. Any higher thrust versions carry consequences on the maintenance cost side as is covered in our up-and-coming Monday article in our Fundamentals series, it covers the series 737 MAX 8 and its engine; CFM LEAP-1B.
Thank you very much, Bjorn!
THE AIRBUS 321 LR PILOTS’ PRAYER
“Sweet Jesus, the Air Force never taught us glider flying, but thanks for that Canadian drag-strip down there.
With Thy Grace, let us glide A-L-L the way to the ‘What-bird’? Islands.
Thy Mercy coined the great TWA gag…Try-Walkin’-Across, right?
Forgive us, three heavy-weather approaches to Saint Croix WERE a bit much, even for St. Christopher…. And the supposedly fun-filled seasonal 727 ferry flight ‘home’…. How many times was Thy name invoked?
And Lord, lead Long Island folks to welcome airliners with empty tanks into their backyards again.
Grant us the A320 SFO-OAK shuttle bid, with a few hundred extra pounds in each wing.
And PLEASE, Dear Lord, send Thy Angel ‘Captain Sully’ to guide all A321LR airmen/airwomen.
Thank you, Sweet Jesus!
Great series of articles.
The questions which require further insight upon relate to the ability of existing wing / engines and LDG Assy to deliver on the required takeoff / climb / cruise and landing performance with the envisaged weights and operational envelope and airfields.
Consider the F / S and Green Dot figures which are required for weight/ wing and thrust combinations to give a good platform , additionally the Crz Opt levels and Mach speeds will be an important factor .
A heavy A321 is a nice machine to fly but needs extreme care on both ends of the speed tape in all stages of flight , especially if abnormal LDG perf considerations are valid
The extra weight for the LR will require some improvements in both powerplant / wing and LDG Assy , IMHO.
The Altitude above you, the runway behind you, and the fuel not in the plane … Murphy’s Law
There’s one assumption in your good & realistic prognoses. The 36 inch business class seat has no place on the Atlantic. an airline offer a consistent business class product, regardless of the aircraft type. These that means a seat converted into a horizontal 80 inch bed. Various configurations exist. For the A321 can can take the AA business class seat as a reference.
Together with a 31-32 inch economy that work work out into a seatcount of e.g. 139 economy and 20 business class, 159 seats. Shaving about ~2500kg of the paylaod.
As your say, IFE is heavy, easily 300-400 kg for 159 seats.
an edit within 30 minutes function would be great.. 😉 was in a hurry
Yes for sure !
This is correct and is the very configuration example we use in the original article series. There are LCC’s that fly long-haul (Norwegian is one example with their 787-8) which does not offer lie-flat, they only have premium economy @46”:
This is the type of recliners Airbus use for their example. So both examples have real world applications.
Bjorn, this is no technical issue.
I used to specify many different long haul aircraft configurations for a big airline. Starting points were airline product specifications, which were determined by market conditions regardless of aircraft types. Then we would do dozens of LOPA’s and have discussion with revenue management and network planning about the numbers of seats. They run different fleet-network simulations.
For Transatlantic, flat business class seats and maybe a few rows economy+ with extra pitch are the standard. Regardless of what Airbus or Boeing thinks. I cannot remember ever consulting / taking into consideration Airbus/ Boeing seat charts/ seat specs working on airline LOPA’s. ~160 Seat two class is my best estimation for a long range A321s. (You need the galley so no Zodiac Space-Flex). For existing 757/A320/321 operators like DL, AA, UA, BA, LH, AF/KL, SAS, IB, AZ, SR that dominate TATL routes.
As I already responded this is exactly what we did for the 757 replacement articles, 16 Diamond lie flats, 48 partway recliners in W thereby re-using the double overwing exits spacing requirements and 98 Y for 162 total.
Wonder why Airbus didn’t arrange for a proper tailtank ? W&B issues ?
Airbus had all components for a A321LR (except for structural beefing which was minor) ready available, the multi ACTs were certified and flying on their ACJ A320 (bizjet) variants. So creating the A321LR was straight forward, no need for elaborate tail-tank developments and certification worries (tail tanks are tricky for limited gains, was left out of A350 for this reason).
Hello Scott ?
Do you know if the 3 ACT will end up in the rear cargo hold ? or will it be split between the front and the rear cargo hold ?
The first two goes in the aft hold and the third in the forward hold, all for CG reasons.
So there’s two sets of plumbing !
One set of plumbing with tubes going forward and backward, passing the wingbox / wheel bay area.
One or two pumps ? maybe I go too far in the detail.
On another point, 97t on 4 main wheels, it will be interesting to see the pavement loading numbers !
Hi Scott. Are all 3 ACT installed after wingbox (in the back)? This must hell influence the center of mass. what can be done as a countermeasure?
Look at a A321 planform drawing, center of lift is around the MLG wheel bay in the length axis; placing the first two ACT directly behind gives the least influence on CG possible, then it is time for the forward hold.
All easily controllable in the standard CG calculations which is part of aircraft load planning and load-sheet creation.
The good work of Airbus with A321LR is more than four fiths the way towards an A322 if customers can accept a straight fuselage-stretch-for-range trade-in. Max rotation at take-off of A321 is 11.3º and – seoo – same for A322 (= A321 + 210″) would come to a flat 10.0º. With room for 13 AKH, the A322 would correct the shortcomings of A321LR in terms of number of free payfreight AKH positions after Checked-in Luggage + ACT. The combination A321LR + A322 feeder – both @97t MTOW – would even better cover the 752 + 753 successor markets … what are the prospects for near-term excursions of MTOW beyond 97t ? Ideally, a development towards 104t is recommendable !
A back-of-the-envelope calculation would seem to indicate that a 97 tonne A322, stretched by 1o frames, would have no less range range capability than the current A321ceo and still be able to fly US transcon routes with a reasonable payload.
I would not be surprised if we see spec creep of the A321LR over the A321NEO this year. Mostly on the wing and a few klbs on the engines.
I thought I had heard 100 times that the 321 is at the limit with its wings and that a true 757 replacement or a further stretch “aka 322” would need a new wing, which at that time could then be carbon and designed in a way that additional tanks would fit in there or another 10 t would be easily feasible.
Is this now all null and void? Or is the 321 LR just a bit of bricolage to cover most of the market and a new wing just not worth it for a few planes more?
I have already touched on this in the response to Uwe. The wing is loaded to about the same level as the 777-300ER (both around 785 kg/m2) but has a considerably higher aspect ratio (11.2 vs 9 ) and the LR has a higher power to mass ratio (0.31 vs 0.30) with the standard 33klbf engines. Further the starting distance is shorter than 777-300ER (or 737-900ER or MAX 9) so why does the A321LR need a new wing when these don’t. The talk about a new wing is assumptions from those that have not done the numbers, the wingloading is high so something needs to be done to the wing if further MTOW increases or stretches should be needed but right now the LR is defined at 97t and is OK with the wing it has.
Both the 777-300ER and A321LR benefit from the fact that they operate at Max TOW relatively seldom. That means over their lifetime they operate mostly where takeoff performance and first flightlevel is comfortably good, then occasionally they are asked to go to the limits which they do and the airline is happy.
A back-of-the-envelope calculation indicates that in order to equal the 777-300ER in wing-loading, the MTOW of an A321LR-IGW/A322 would be around 100 metric tonnes. Interestingly, the A340-600HGW has a considerably higher wing-loading — i.e. 870 kg/m2 vs. 783 kg/m2 for the 77W)– With a wing-loading as high as 870 kg/m2 the MTOW of an A321LR-IGW/A322 could be as high as 111 metric tonnes; not taking into account, of course, that a quad has a better takeoff performance at the same take-off weight.
Maybe wingloading during take-off is more relevant, with all lift adding devices in place. You can add a lot but it takes weight, fuel capacity and relative much lift induced drag.
in principle you are right, this is not how the aero guys see things however. The wing area one use for wingloading measurement is not the actual wingarea, it is a reference area that remains constant even when e.g. flaps with fowler effect are used. They catch the effect of the enlarged wingarea in the lift coeffient instead, thereby they can compare different ideas around high lift devices etc using one parameter, Cl, the wings lift coefficient. The A321 has a good flap system with a nice fowler effect but that is included in the takeoff distance calculations. The critical drag is the induced drag directly after liftoff, see our Fundamentals 3 article https://leehamnews.com/2014/11/19/fundamentals-of-airliner-performance-part-3/ , this is helped by the addition of sharklets. The high lift devices raises the parasitic drag, i.e. drag independent of lift.
Remember, that for any given length of wing, the actual span from tip-to-tip decreases when the wing sweep angle is increased. Wing sweep angles for the A321 and the 777 are 25 and 31.6 degrees, respectively. Induced drag is inversely proportional to the aspect ratio of the wing, which means that higher aspect ratio wings give slightly more lift at low speeds. As Bjorn pointed out, the aspect ratio of the A321 wing is significantly higher than the AR on the 77W wing. Also, the A321 wing not only has both outboard and inboard double slotted flaps compared to the A320’s single slotted flaps, but there is also a tapering chord extension on the trailing edge outboard of the engines and a constant chord extension on the trailing edge inboard of the engines, thus increasing the wing area by about 4 square meters.
“The issue is of course airliner-to-airliner, not BBJ-to-airliner. In the former, Airbus has the advantage, and sales figures bear this out: the A321neo is outselling the 737-9 by a ratio of 2.6:1.”
Thank you for including that, my take was it was an apples to rutabaga comparison.
From that conference also they made a big deal about how they put out more aircraft despite fierce competition.
More BS, its not like Airbus has subversive agents in the Boeing plants and production and sabotaging the Boeing system.
Any issues Boeing has competition wise are purely self inflicted.
Any issues Airbus has competition wise are purely self inflicted.
I split Airbus into the new era vs the old. With the new structure I believe they are succeeding for the most part on being a competitive company rather than an arm of the various European Airbus launching states.
That said, they still have aspects involved in that. The A380 being one they inherited and its a political hot potatoes as well as a resource user for no foreseeable gain (obviously you disagree but that’s my take as the program looks never to make any money) said resources better spent in a product that will make money.
Tough spot to be in that current management had nothing to do with.
Current management had nothing to do with it? Tom Enders, Fabrice Bregier, Harald Wilhelm and John Leahy, to name a few, where all there before the launch of the A380.
EIS I mean…
Looking at Boeing the “mainstreaming” of Airbus has the potential to shorten its planning horizon.
The accumulated Airbus potential has not been gained from pure market mechanics quite the contrary ( and could not have been achieved on that path. )
I see what most everybody and Scott lauds as a loss.
2A: who was responsible for all of it and the older structure were all different.
It seems to me that Enders et all are working to making the structure as business like as it can get. That may just me of course.
Worth noting that Airbus has previously used just an “R” to indicate the extended range variant of the A300. i.e. A300-600R
Just for the fun of it, I would so want to see the numbers if one used a next generation PW GTF or the RR Ultrafan with 10-15% improvement in fuel burn over the current ones. Range, payload, no. of ACTs etc… and does today’s wing become tomorrow’s “optimum-size” under such conditions?
What are the prospects for an extra tank in the 737m8 ?
Latest rendition of wingtip looks nice-
Even more interesting than the shape is the aerodynamic profile, it is a laminar flow profile delaying the onset of turbulent flow on the winglet blades.
We have looked into adding extra cargo bay tanks to the MAX 8;
The 737 has a better starting point than A320, its wing holds about 2/3 of an ACT of more fuel therefore the need for extra tank would come later in the range search. The MAX 8 is weight limited however, this means adding extra tanks (they are available from the biz jet program as for A320) does not bring anything until Boeing releases a version with a higher MTOW.
Its standard range of 3600nm enables long haul possibilities, we described what could be achieved in the article. The MAX 8 would have attractive seat cost for the sectors it could take on.
Bjorn do you know the max number of ACTs that can be fitted to an A321 CEO? If 4 x tanks could be fitted, my back of envelope calcs suggest it could work as an all biz transatlantic platform (e.g. 62 Thompson Aero Vantage)
I am writing my bachelor diploma thesis on Airbus 321neo LR in long-haul segment. I found this article very useful, but could you give some links and references that you took infromation from?
I did not take information from other places. I have a complete performance model for airliners that calculate all these values. It’s nothing that is easy to replicate, it took several years to develop the model.
Take the information from our articles and make a note that it was produced with a comprehensive first principles model.
One thing that I am concerned about with the new 321 Neo LR is, having flown both the 321 and 757, I am aware of the 321’s very poor climb performance at higher weights as well as the flight envelope limitations associated with it. The yellow bars get very close at those weights. Also, the 321 cruises at Mach .78 with a max ceiling of 39000 feet which I can honestly say I was never able to make when the aircraft was relatively light. The 757 cruises at Mach .80, has a ceiling of 42000 feet and has far superior climb performance. In a Transatlantic capacity, what levels would the 321 make over the ocean given it’s poor climb performance? Will the new engines rectify this? Also, a single bogie for a 97 tonne aircraft will increase bearing limits and no doubt increase accelerate stop distances required. Also, there will be no freight capacity which is available on the 757.
All of these questions for an aircraft that has the same range as a 30 year old 757-200 with winglets. I could be wrong, but there is so little information available on the 321 Neo LR, I’m a bit concerned.
You overlook the (massive?) difference in fuel use for the same payload. In the payload/range overlays shown the A321LR seems to fully “overlap” the 752 ( except for a rather small inversion at the first corner.)