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The Enigmatic A350-800  
User currently offlineferpe From France, joined Nov 2010, 2804 posts, RR: 59
Posted (2 years 3 months 12 hours ago) and read 7513 times:

I once tried to start a thread about the A350-800, guess there was to much to read before one came to the conclusion:

Airbus Strange Definition Of The 350-800 (by ferpe Sep 17 2011 in Tech Ops)


Here my wonder straight of the bat:

- Why have A put the revised A350-800 MTOW at 259t? (the original 248t now seems more a weight-variant, ie paper derate). It makes it having no salient characteristic and in it's size class it is overshadowed by the 789.

- Why not offer a 268t variant as well, my calculations put it at a 9150nm spec range and as such it could take over the job of the 777-200LR on thin routes (it seats 30 Pax less), instead of 141t trip fuel for a 9000nm leg it would need 100t    .


That would be a 40t saving or 40%    which could make many ULH city-pairs feasible which does not work with todays frames  Wow! .

I know it is a small market but the 777-200LR and A340-500 have sold about 100 copies together and a 268t A358 would not be different from a 259t variant as what you add would be fuel only ie the OEW could potentially be the same (with some clever tuning of the FBW for loadalleviation) or marginally higher. All the stuff is there to carry the weight and the tanks start to limit beyond the 9200nm point.

Thus the ultra-long-range 268t A358 would be merely a weight variant with unique features, why not offer it    , it would have this market to itselves at that fuel burn level ?


Non French in France
28 replies: All unread, showing first 25:
 
User currently offlinepoLOT From United States of America, joined Jul 2011, 2259 posts, RR: 1
Reply 1, posted (2 years 3 months 11 hours ago) and read 7497 times:

Quoting ferpe (Thread starter):
- Why have A put the revised A350-800 MTOW at 259t? (the original 248t now seems more a weight-variant, ie paper derate). It makes it having no salient characteristic and in it's size class it is overshadowed by the 789.

Was this done when Airbus decided not to optimize the A358 and instead make it just a straight shrink? What was the original MTOW?

Quoting ferpe (Thread starter):
Thus the ultra-long-range 268t A358 would be merely a weight variant with unique features, why not offer it , it would have this market to itselves at that fuel burn level ?

Very few 777-200LR and A345 customers are using their planes at max range. For most of them the standard A358/A359 will probably be good enough. Even if you pretend the price of fuel is much lower the number of viable ULH flights is rather limited, due to fact that many places that far away have limited economic or tourism ties.


User currently offlineferpe From France, joined Nov 2010, 2804 posts, RR: 59
Reply 2, posted (2 years 3 months 9 hours ago) and read 7420 times:

Quoting poLOT (Reply 1):
Was this done when Airbus decided not to optimize the A358 and instead make it just a straight shrink? What was the original MTOW?

Yes, the original CFRP 350-800 (the warmed over 330 variant was also called 350-800 IIRC ) was an optimised shrink, ie it had it's own weight optimized landing gear with smaller brakes, wheels etc, the aircond was reduced, the fuselage structure thinned etc. It had a 245t TOW and then it was raised to 248t when A raised all variants 3t.

The straight shrink left everything the same from the 359 except cutting the forward section 4 frames, aft section 6 frames and restressing the upper mid section panel. One aircond cell is also deleted and oxygen and firefighting bottles are reduced. This mean that everything except the upper mid panel is stressed for 268t, why then restrict the frame to 259t and drag those extran kilos around with no use? You virtually amputate the frame of 650nm (9t of fuel), and I ask myselves for what reason?

Quoting poLOT (Reply 1):
Very few 777-200LR and A345 customers are using their planes at max range. For most of them the standard A358/A359 will probably be good enough

I would have thought you use them on legs where your normal fleet can't do the job, why buy them otherwise? You drag inefficiency around on a daily basis in this case, the 200ER is 18t lighter then the 200LR and the 340-300 is a whopping 38t lighter then the 340-500 for the same cabin space (the 333 is 45t lighter).

Note that the 358HGW would be a mere 5t heavier then a 789 and perhaps the odd ton heavier then a non HGW 358.



Non French in France
User currently offlinepoLOT From United States of America, joined Jul 2011, 2259 posts, RR: 1
Reply 3, posted (2 years 3 months 9 hours ago) and read 7405 times:

Quoting ferpe (Reply 2):
I would have thought you use them on legs where your normal fleet can't do the job, why buy them otherwise? You drag inefficiency around on a daily basis in this case, the 200ER is 18t lighter then the 200LR and the 340-300 is a whopping 38t lighter then the 340-500 for the same cabin space (the 333 is 45t lighter).

Airlines also bought them (specifically the 772LR, I don't know about the A345- that aircraft is not Airbus's finest hour) to do routes that the normal variants could do, but with more payload. I can't remember exactly, but I believe it is around 5000nm where the 772LR starts to be more efficient (lift more payload) than the 772ER. For most airlines I am guessing that the standard A350s will be efficient enough vs the 772ER for most operators that a ULH version of the A358 won't be needed (and they would probably be more interested in an ULH version of the A359 instead anyways).


User currently offlineStitch From United States of America, joined Jul 2005, 31110 posts, RR: 85
Reply 4, posted (2 years 3 months 9 hours ago) and read 7390 times:
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Airlines appear to be buying the 777-200LR for it's payload-range - it's a real freight train. The A350-800 lifts a significantly lower payload than the 777-200LR - some 20t less based on charts and comments provided by Airbus. As such, I don't see the A350-800 replacing the 777-200LR on high-payload missions as it lacks the space and the lift.


As to why Airbus offered a 259t MTOW, I believe it was to try and convince A330-200 operators to order the type. Per Airbus, the A350-800's payload is not much more than the A330-200 (some 3 tons), so they're selling the range - 1400nm farther than the A330-200. However, as above, nobody's really exploring ULR missions so airlines seem to be saying "meh". Therefore, with few if any carriers needing the A350-800 at 259t, the market for a 268t is even smaller.

I could see SQ taking a handful to replace their A340-500s on LAX/EWR-SIN, but as the A380-800 becomes more capable, it may be possible for SQ to use that plane on those missions (with perhaps a more comfortable Economy cabin with less seats to lower DOW).

Overall, however, I expect the A350-800 to be the weakest seller of the family and the 787-9 to be the more popular choice - especially for carriers who also operate the 787-8 (and/or 787-10X).



Quoting ferpe (Reply 2):
You drag inefficiency around on a daily basis in this case, the 200ER is 18t lighter then the 200LR...

In terms of OEW, the 777-200LR is 7t heavier than the 777-200ER in an effectively identical Boeing OEM configuration - 145t vs. 138t.

[Edited 2012-07-23 12:44:17]

User currently offlineferpe From France, joined Nov 2010, 2804 posts, RR: 59
Reply 5, posted (2 years 3 months 8 hours ago) and read 7323 times:

I made a payload-range diagram based on the latest ACAP for the 200ER and LR, 789 and the 800 and 800HGW (click on it to enlarge it):

http://i298.photobucket.com/albums/mm262/ferpe_bucket/Payload-range800HGWvs200LR.jpg

As can be seen the 200ER has a higher MSP (the 200LR is heavy) and is the better lifter below 6000nm by a margin, the 800HGW (which has the 800 OEW and the 900 ZFW) is a phenomenal lifter but would be totally volume constrained so the 70t MSP is pointless, some 55t would make more sense. Anyway the 800HGW would go some 1200nm longer then the 789 in the interesting 25-35t payload range.

It would also haul 35t 8000nm where the 200LR would do 9000nm but at some 2/3 the fuel burn, at a cabin filled with some 250-270 people (25-27t) there is not much difference between the 800HGW and the 200LR except for the fuel burn.

The slopes of the MTOW limited part of the diagram tells you the fuel burn, the 777 trades more kg fuel/nm then the new crop (789, 800, 800HGW) Big grin .

[Edited 2012-07-23 14:13:09]


Non French in France
User currently offlineCM From , joined Dec 1969, posts, RR:
Reply 6, posted (2 years 3 months 7 hours ago) and read 7272 times:

Quoting ferpe (Reply 5):
I made a payload-range diagram

Ferpe, there's such a huge difference in the MZFW lines of those airplanes, I suspect the baseline A350 structure (floors & wing center section in particular) could never handle the cargo density this represents. These structures could be made to handle it, but that would add OEW to an airplane which is already widely viewed as sub-optimized. I suspect driving the A350-800 to higher gross weights is exactly the opposite direction most operators are pressuring Airbus.

This industry is wise to the cost of payload/range. With the exception of a very short list of operators (I can count them on one hand), most carriers are averse to and critical of airplanes which offer more capability than their network demands. I have this discussion regularly with airlines who feel we are offering capability they do not need, and view this capability as an efficiency penalty to the airplane. See the recent success of the A330-300 and the scarce orders for the 777-200LR as examples of airlines voting with their feet on this very issue.

As a shrink aircraft, payload/range is one thing the A350-800 should be able to add quite easily. However, the vast majority of operators don't need range over around 7,000 nm to accommodate their existing network or to support their future network strategies. I think Airbus will see far better interest in the A358 if they throw any added design effort after efficiency rather than 9000nm range and the payload capability that represents.


User currently offlineStitch From United States of America, joined Jul 2005, 31110 posts, RR: 85
Reply 7, posted (2 years 3 months 4 hours ago) and read 7195 times:
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Quoting ferpe (Reply 5):
I made a payload-range diagram based on the latest ACAP for the 200ER and LR, 789 and the 800 and 800HGW (click on it to enlarge it)...
MSP for the 777-200LR is 64t, not 52t.

And there is no way an A350-800HGW will out-lift a 777-200LR. Heck, your 70t value for the A350-800HGW is higher than the MSP for the A350-1000.  

Airbus' own charts show an MSP of ~50t for the A350-800HGW vs. 45t for the A330-200HGW (238t).

The 787-9 was 58t as of 2005, so that looks good, but the 777-200ER should be above it, as it's 59t.

[Edited 2012-07-23 18:12:32]

User currently offlineferpe From France, joined Nov 2010, 2804 posts, RR: 59
Reply 8, posted (2 years 2 months 4 weeks 1 day 22 hours ago) and read 7106 times:

Quoting Stitch (Reply 7):
MSP for the 777-200LR is 64t, not 52t.

And there is no way an A350-800HGW will out-lift a 777-200LR. Heck, your 70t value for the A350-800HGW is higher than the MSP for the A350-1000.  

Thanks     , haven't used this part of my little sheet for a while and did the chart on the double   , here is a better one (actually the faulty MZFW which should have come from the -900 came from CMs brainchild the -950    as I converted this column from -950 to -800HGW ) . This should then serve better as a basis for discussion:

http://i298.photobucket.com/albums/mm262/ferpe_bucket/Payload-range800HGWvs200LR-1.jpg

I have still left the -800HGW MZFW the one from the 900 just to show the effect, once again it can make sense to lower it to something floors etc can accept without reinforcements.

@CM, your comments are exactly the ones I wanted. When making the cut and shut -800 A can only seek efficiency in the parts they touch. To my understanding that is section 11-14 (forward fuselage that they shorten), section 16-18 (aft fuselage that they shorten). On the middle section the don't change anything and could leave it intact, here they thin the top panel which is straightforward to change as it is a simple uniform panel. They don't touch the complicated parts around the wing junction, one can understand that, it can be a can of worms (what do you touch and don't). My problem was (but I am getting over it slowly now with the wisdom from CMs all encounters with Airliners) that the key structural parts (wing, MLG, centre section, engines, cockpit with NLG, empennage....) all were capable of 268t and bringing it there would perhaps cost an additional ton in the touched parts (or even less).

I ran the extra ton OEW for the -800 in my model on a 7000nm leg, it costs 0.5% in fuel burn. Guess it would not be worth sacrificing this 0.5% for all customers to enable the 268t HGW variant with a 9100nm range   .


PS
The wrong MZFW came as I quickly converted my A350-950 (CMs proposed -900 with the -1000 fuselage in a -1000 thread) to a -800HGW, I did not lower the MZFW to the original -900 again. The -950 goes exactly in the direction CM is putting forward, the airliners want max efficiency for their main route network, it had (has ) a phenomenal fuel burn per seat, it also had the range of the 787-10, 6800nm  . DS

[Edited 2012-07-23 23:45:17]


Non French in France
User currently offlineCM From , joined Dec 1969, posts, RR:
Reply 9, posted (2 years 2 months 4 weeks 1 day 22 hours ago) and read 7098 times:

Quoting ferpe (Reply 8):
here is a better one

Interesting stuff, Ferpe. Can you tell me about the fuel volume limit lines on your P/R chart? It looks like the A350 models are able to trade payload for range much more efficiently than the 787-9. In fact, the 787-9 trades payload for range at about the same ratio as the 777-200ER. What fuel burn does your model assume for these three aircraft?


User currently offlineferpe From France, joined Nov 2010, 2804 posts, RR: 59
Reply 10, posted (2 years 2 months 4 weeks 1 day 22 hours ago) and read 7082 times:

Quoting CM (Reply 9):
Can you tell me about the fuel volume limit lines on your P/R chart? It looks like the A350 models are able to trade payload for range much more efficiently than the 787-9. In fact, the 787-9 trades payload for range at about the same ratio as the 777-200ER. What fuel burn does your model assume for these three aircraft?

The payload range charts is still old technology by me , I have not run the points through my model yet (still trying to get the SA frames to make sense before using it for my P/R charts). I used the spec case + the regulatory reserves to get the average fuel burn for the spec trip then just scaled that to extrapolate back to MZFW and up to the fuel volume limit. After the fuel volume limit brake the slope down to max range and no payload is not very reliable (used to put in a caveat for this if you go back to my chart times  ).

The average FF for the 789 on the 8000nm leg was 5.5t/hr, -800 5.3 and -900 5.6. My model has it at 5.55, 5.37 and 5.65. When I look at the 789 fuel limit slope it seems to be something wrong as well, will check it.

Getting those R/P charts up to snuff is WIP   .

[Edited 2012-07-24 00:31:18]


Non French in France
User currently offlineairmagnac From Germany, joined Apr 2012, 316 posts, RR: 52
Reply 11, posted (2 years 2 months 4 weeks 1 day 19 hours ago) and read 7012 times:

Quoting ferpe (Reply 10):
Getting those R/P charts up to snuff is WIP

It is already very interesting, and I wish to thank you for your efforts in the several Tech/Ops threads and the A350 development thread you initiated !   


My own thoughts on this A350-800 subject are less quantitative, but I am wondering if this "strange definition", as you put it, is not a consequence of Airbus management simply playing a waiting game.
The decision to revert to a simple shrink rather than building an optimised frame was made around the end of 2009/ early 2010. At that time, with the A340 already in its death throes, I guess that the main priority was to "plug the hole" in the Airbus offering. Meaning establishing the -900 in between the 787 and 777 where it would have some market space to itself, then bring out an optimised upgauge to move in on the 77W. That much being decided, now there is the question of what to do with the 200-300 seat market, and this is where many questions would pile up, as any A350 variant here would only come out around 2017-2018 at the earliest, so 8 years down the road from the decision point.

8 years is quite a long time, and this is a very active part of the market, so Airbus management would have been faced with many questions :
How well would the A350 development/industrialisation go ? Where will we stand regarding optimisation of the frame (weights, engines...) ?
What will B be doing ? What will the 787-9 be like ? Will there be a 787-10 ? What will they be doing with the 777 ?
Where will we stand regarding the A330 ? will it be on its way out, or still holding some ground ?
Will we need to develop a new SA product at that time ? (in Jan 2010, the NEO discussion was just beginning)
Will the market be requesting us to develop an A380-900 ?
And those would just be the questions about the airliner market, then you still have questions regarding economic conditions etc...
Of course, Airbus employs competent people to try to answer those questions, but it is difficult and anyway, few airlines would order so far in advance (see the -1000, or 787 ordering history), so what is the point in rushing into a new development ?

Add to that the quotes we have here :
http://www.flightglobal.com/news/art...be-developed-as-900-shrink-337033/
Leahy says: "The more we looked at [changes on the -800], the more we thought: 'Why?'"

http://www.flightglobal.com/news/art...rethink-on-a350-800-design-337132/
Says the programme's marketing chief Sophie Pendaries. "The planned optimisation of the -800's design - slight changes to the structure and landing gear, tyre and brake changes - was not bringing the expected benefits"

Maybe the tweeking of the design decreased the commonality and so increased the specific costs, while not bringing any performance increase that could be judged sufficient to fit into the market 8 years later.

In the end, maybe an optimised A350 shrink would be a proper response. Maybe an improved A330 would be better. Maybe a whole new family would have to be developed. To decide, some answers would be needed, but that takes time. So let's delay any major decision for a few years till we actually see how things are going.
In the mean time, to avoid vacating the market entirely, go for the cheapest, simplest, otpion : just take a few frames off the -900 and change nothing else, see what performance numbers result, and offer that.
Low cost, low risk, should not introduce too many headaches, but it will buy some time.
If some airlines like it, good. If not, well at least there is something occupying some market space, and it didn't cost much.

And after all, Airbus did sell a quite respectable number of them (currently 118, although many of those are at risk, or worse : Afriqiyah, or Air Libya for example). 118 is much better than nothing at all, so maybe it wasn't such a bad idea ?



One "oh shit" can erase a thousand "attaboys".
User currently offlinepanais From Cyprus, joined May 2008, 463 posts, RR: 0
Reply 12, posted (2 years 2 months 4 weeks 1 day 18 hours ago) and read 6971 times:

If you look at it from Airbus's vantage point, you will see that to them, the A350-800 is more fuel efficient than the A330-200 and the A330-300 it replaces. As a new design it will also cost less to maintain and with pilot training and engine parts commonality, it will create economies of scale for any airline that operates the A350. This makes it a great people mover just like the A330-300 is now, which has about 50% of the A330 orders.

Is there still a market for a 250 seat widebody? Maybe, Boeing is sold out for the next few years so we do not know in 2020 what airlines will be ordering.

In my opinion, Airbus does not see a market in 2020 for a 250 seat widebody plane. For ranges below 3,000 nm, the narrowbody will be more efficient, for more than 5,000nm, the 787-8 is too small in size and payload to make a 3-class route profitable.


User currently offlineferpe From France, joined Nov 2010, 2804 posts, RR: 59
Reply 13, posted (2 years 2 months 4 weeks 1 day 8 hours ago) and read 6738 times:

I agreed with CM that the fuel limited part of my P/R chart looked odd so I checked it. First of all I once again realized how difficult that part of a chart is to extrapolate using the OEMs spec data as a reference. The spec range and payload implicitly tells you the average fuel burn in a MTOW leg, you just have to get the OEW and the reserves right. One can then with reasonable accuracy extrapolate back to the MZFW point and forward to the Max fuel point, all points along the MTOW part is flown with the same flight profile and therefore induced drag and fuel consumption profile up to the point.

Once past the max fuel point one no longer trades payload for fuel, one starts with a lower TOW to gain range at the expense of payload. Then the whole step-up cruise is different and so is your induced drag all along the leg and your extrapolation breaks down. I used the max fuel less reserves with an assumed average FF for the no payload leg to seek that range point. I historically used PianoX and the 787 to get a hunch of the relation to the spec average FF and applied that ratio to other similar frames, a method which has large pitfalls, something I also knew and flagged when showing the diagrams of late.

I now have a complete aircraft model including a way to handle different step-up cruise profiles. Checking the 789 and the -800 (the 777 data is from ACAP) showed that the 789 was reasonably correct but the -800 flew to long without payload, here my final shot at the chart   , (I don't think the fuel limited part is the interesting part but I wanted to understand what was wrong) :

http://i298.photobucket.com/albums/mm262/ferpe_bucket/Payload-range800HGWvs200LR-2.jpg


This whole thing has now convinced me I need to make a makro for my model to paint the P/R diagram but it will stretch my excel programming a bit so will take a while  .



Non French in France
User currently offlineferpe From France, joined Nov 2010, 2804 posts, RR: 59
Reply 14, posted (2 years 2 months 4 weeks 1 day 7 hours ago) and read 6711 times:

@ airmagnac and panais, I think your posts carry a lot of sense, I would add to these my own additional reflection (on top of CMs experience which IMO explains the present -800s definition):

1. The A350-800 has become the ugly duckling after the -1000 to some extent. I am not sure it deserves all this "it is no good and will be skipped". When I run it it is a very efficient frame, it has exactly the same fuel burn per m2 cabin space as the 789 on a 8000nm leg. The problem is that the 789 is more efficient on the more common shorter legs (it is lighter) and has more earning potential, it's cabin is longer (and a smidgen narrower) thus one can probably get a few more seats in those m2 then the -800 and it carries a full 8 LD3 more. Further the 789 is available 2 years earlier (at least) and is the second iteration of an architecture with a lot of milage, ie it is likely to be good, very good and the -800 is rumored to be overweight and late. I think the overweight will depend on As interest to work it, if they invest anything near the effort it deserves it should come in some 5t over the 789 which should be OK and which is what I have modeled.

2. So given it's (unfortunate  ) competitive situation and the fact the A earn less margin on it then the -900 A fields it to cover a market area and to make good on those that have ordered it. It also makes a lot of sense if you have a large A fleet and use the other 350 models or need the range it can provide. It will also have excellent hot and high performance, the wing and engines are made to carry a -900 out of a hot and high place (the hot and high is not quite the 789s forte, it has a very high V2 speed it needs to reach should an engine decide it needs a break (182 vs 160kts for the -800)   ).

3. Those who have ordered it probably got a good price, thus A commits to deliver on these promises with least possible risk and effort. It just might be so (given what I have shown above) that while stressing the touched parts and with the -900 test flight data in hand that A will stress and tune the -800 so that they make good on commitments but can field a 268t variant later pretty easily. In such case they can ask a premium for this model from the handful of customers that want it and can charge anyone who wants the upgrade as well. But why boast that now and increase the risk budget for little gain, stay calm and take that Ace out of your jacket later    .


PS
I also came to realize the -800 will be a fun one to fly, those 84klbf engines with the big wing will make for some nice climbs after gear-in should one have "forgotten" to program the FMC derate, the 757 of the 2020ies    DS

[Edited 2012-07-24 15:17:27]


Non French in France
User currently offlineLAXDESI From United States of America, joined May 2005, 5086 posts, RR: 47
Reply 15, posted (2 years 2 months 4 weeks 1 day 6 hours ago) and read 6682 times:

Quoting panais (Reply 12):
If you look at it from Airbus's vantage point, you will see that to them, the A350-800 is more fuel efficient than the A330-200 and the A330-300 it replaces.

  
As per my model, for a 5,000 nm mission, A358 should burn about 15% less fuel than A332HGW for the trip, while carrying nearly 30 more passengers.

For the same mission as above at MTOW, A358 burns roughly the same amount of fuel as as a " fully mature" B788, while carrying more passengers. A358 is nearly 13 feet longer than B788(about 5 additional Y rows = 40 to 45 Y seats).

A358 is $55 million more expensive than B788 at list, and is nearly $50 million more expensive than A332. With 50% discount, the net price difference of nearly $25 million will negate a large portion of the operational advantage of A358 over A332 and B788.


User currently offlineStitch From United States of America, joined Jul 2005, 31110 posts, RR: 85
Reply 16, posted (2 years 2 months 4 weeks 1 day 5 hours ago) and read 6670 times:
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Quoting LAXDESI (Reply 15):
As per my model, for a 5,000 nm mission, A358 should burn about 15% less fuel than A332HGW for the trip, while carrying nearly 30 more passengers.

In April 2010, A350 chief engineer Gordon McConnell claimed a 23% fuel burn reduction per seat on a 4000nm mission compared to the A330-200 (also seating 30 more than an A330-200).


User currently offlineLAXDESI From United States of America, joined May 2005, 5086 posts, RR: 47
Reply 17, posted (2 years 2 months 4 weeks 23 hours ago) and read 6566 times:

Quoting Stitch (Reply 16):
In April 2010, A350 chief engineer Gordon McConnell claimed a 23% fuel burn reduction per seat on a 4000nm mission compared to the A330-200 (also seating 30 more than an A330-200).

My model yields about 25% lower fuel burn per seat in favor of A358 for a 4,000 nm mission, which is close to Airbus estimate.

Assuming two 4,000 nm missions per day, A358 saves about $9,000 per day in fuel costs(2,600 gallons X $3.50), which is about $3 million per year. Assuming a fifteen year life, present value of the fuel saving is about $23 million over the life of aircraft at 10% cost of capital.

One needs to add revenue potential of 30 additional seats of A358 on some of the current A332 routes. Assuming 70% load factor on the additional seats at lower average ticket price($400) on each 4,000 nm mission, A358 could earn about
$6 million more per year.

In summary, A358 could have an annual operational advantage of nearly $9 million over A332 on some routes, which is enough to offset the A358 net additional acquisition cost of $25 million in about three years. Not a bad payback period.

Ignoring additional passenger revenues, it will take about 10 years for an airline to recover the higher cost of A358 from fuel savings. IMO, A358 at $15 million more than A332 is a good value.


User currently offlineCM From , joined Dec 1969, posts, RR:
Reply 18, posted (2 years 2 months 4 weeks 23 hours ago) and read 6564 times:

For reasons of expedience,I believe Airbus will initially deliver a fairly simple shrink of the A359 in the A350-800. This airplane should have excellent mission capability at the price of our previously discussed efficiency penalty. I see this airplane being a tough sell in Europe where there is minimal demand for the kind of range this airplane would offer and where there can be extraordinary airport fees based on airplane operating weights. Middle east and Pacific rim operators would love it.

After this airplane entered service, Airbus could do the opposite of what OEMs have traditionally done with many other types by moving backward from that very capable A358 frame. Take the 777-200 as an example of a typical model evolution:

Year...........Model...........................MTOW........Design Range........Sold
1995 .........777-200 A-Market............545K ...........5120nm...............88
1997 .........777-200 IGW ..................632K ...........6940nm...............70
1997 .........777-200ER .....................650K ...........7370nm...............80
1998 .........777-200ER .....................656K ...........7510nm...............278
2006 .........777-200LR .....................766K ...........9290nm...............57

Boeing incrementally added structural capability, wingspan, thrust (and OEW) to gain mission capability. These things came at an efficiency penalty, but in the process the 777-200 truly covered the market and has sold nearly 600 units (not counting the freighter).

I see the potential for Airbus to achieve the same thing, except in reverse. Deliver the initial HGW A358 with all the mission capability it will ever have. This is the path of least resistance as it is minimal change from the A359. Then, over the next few years offer 1 or 2 reduced weight versions which have been re-optimized for lower operating weights. Perhaps a 6500nm - 7000nm version aircraft which takes out several tonnes and operate at much lower thrust.

Airbus has only a couple alternatives to the above:

1. Invest in a major upgrade of the A330 - probably more expensive than an re-optimized A358, even with a new engine.

2. Continue to compete in the 200-250 seat market with small improvements to the A330-200 offered at increasingly heavy discounts (didn't work great for the 767 against the A330).

3. Concede much of the small widebody / moderate range market to Boeing.

One litmus test for the A358 will be Lufthansa. Generally speaking, LH leans toward buying Airbus aircraft. However, LH is quintessentially German and they cannot help being pragmatic in their buying decisions. As such, LH is highly averse to buying aircraft with capability they will not use. The 787-9 and 787-10 are a very nice fit for LH's network. Airbus will need to see if they can defend a good widebody customer by offering an airplane that is compelling for replacement of A340-300s and A330-300s flying routes like FRA-ATL, FRA-DEN and FRA-DXB. As currently defined, the A358 is not the most efficient replacement aircraft available for the aircraft flying these routes.


User currently offlineferpe From France, joined Nov 2010, 2804 posts, RR: 59
Reply 19, posted (2 years 2 months 4 weeks 9 hours ago) and read 6374 times:

@LAXDESI:

Could you help us with an economical analysis A350-800 at 259t (todays spec) and the 789 (todays spec)? You can pick your your model data if you want or mine for fuel burn, here is what my model says for a 7000nm trip: 789 78.0t trip fuel and 350-800 75.2t trip fuel. Lets run it with the nominal cabins, 280 vs 270 pax and see what happens. You can run it with what you think would be reasonable cargo or take the input from my question below (lets assume it is a LH case  Wow! , we would try to second guess their deliberations just to make things more exiting  ) .

To all:
What LH leg would require a 7000nm still air range when one includes the extra trip reserves of some 4-5% that airlines add to the regulatory ones reserves and the alternatives that would be possible?

What would be the typical pax and cargo yields one would get on such a trip in a normal world economy?

[Edited 2012-07-25 13:15:19]


Non French in France
User currently offlineLAXDESI From United States of America, joined May 2005, 5086 posts, RR: 47
Reply 20, posted (2 years 2 months 4 weeks 5 hours ago) and read 6307 times:

[

Quoting ferpe (Reply 19):
Could you help us with an economical analysis A350-800 at 259t (todays spec) and the 789 (todays spec)? You can pick your your model data if you want or mine for fuel burn, here is what my model says for a 7000nm trip: 789 78.0t trip fuel and 350-800 75.2t trip fuel. Lets run it with the nominal cabins, 280 vs 270 pax and see what happens

Going by your numbers, difference is about 900 gallons lower trip fuel burn for A358 relative to B789 on a 7,000 nm mission.

Assuming one 7,000 nm trip per day, A358 saves about $3,150 per day in fuel costs, which is about $1.15 million per year.

Assuming 70% load factor on the additional 10 seats of B789 at an average price of $800 yields $5,600 in additional revenue relative to A358, or about $2 million per year. However, going by the 7 feet length advantage of B789 over A358, the seat advantage to B789 in 9-abreast Y is likely to be closer to 20 seats.

Ignoring cargo, the net advantage to B789 is about $1 million per year, or about $7 million present value benefit over the life of the aircraft at 10% discount rate.

A358 at list is about $20 million more expensive than B788 at list, but I suspect it is unlikely to be more expensive than B789 on a net basis.

B789 in 9-abreast Y with 20 Y seat advantage over A358 makes about $4 million more annually.


User currently offlineLAXDESI From United States of America, joined May 2005, 5086 posts, RR: 47
Reply 21, posted (2 years 2 months 4 weeks 5 hours ago) and read 6296 times:

Comparing the 314 seat A359 to 280 seat B789, my model suggests negligible difference in fuel trip burn and cargo for a 7,000 nm trip. However, A359 is nearly $50 million more at list.

At 70% load factor, the extra 34 seats may earn about $7 million more per year. So it may take about 5 years in discounted cash flow to recover the extra net cost of $25 million relative to B789.


User currently offlinepanais From Cyprus, joined May 2008, 463 posts, RR: 0
Reply 22, posted (2 years 2 months 3 weeks 6 days 15 hours ago) and read 6130 times:

Quoting LAXDESI (Reply 20):
Going by your numbers, difference is about 900 gallons lower trip fuel burn for A358 relative to B789 on a 7,000 nm mission.

Any data on how the difference looks like on a 4,000 and a 5,500nm trip?


User currently offlineferpe From France, joined Nov 2010, 2804 posts, RR: 59
Reply 23, posted (2 years 2 months 3 weeks 6 days 13 hours ago) and read 6086 times:

Here what I get out of my model (OEW 125 and 130t):

5500nm:
The 789 starts with TOW 218.8t and the -800 with 221.7t, they have trip fuels of 59.7 and 58.7 respectively. When the -800 previously had a mid cruise FL of 390 and gained over the 789 who because of the higher wingloading climbed 330-350-370-390-410 (mid 370) it now can fly almost the same profile as the -800 (mid cruise FL390). At 220t TOW the 789 wing is in the design window from it's donor, the 788.

Now the -800 could also fly a higher profile then before but because of the stop in decline of the temperature above FL360 the nm/kg fuel actually decrease at midweight over FL390 (at least in my model   ). So the -800 goes almost directly up to FL390 but then step climbs much slower as the curve for optimum FL vs weight is much flatter above FL360.

@real airline pilots, does this jive with reality as well?


4000nm:
The 789 starts with TOW 201.4t and the -800 with 205.1t, they have trip fuels of 43.0 and 42.9 respectively.


We can clearly see how the lower TOW makes the 789 come into an optimum design area for it's wing and the -800 is going further and further away from it's wing optimum which is around the -900 weights.

[Edited 2012-07-26 08:57:47]


Non French in France
User currently offlinepanais From Cyprus, joined May 2008, 463 posts, RR: 0
Reply 24, posted (2 years 2 months 3 weeks 4 days 23 hours ago) and read 5738 times:

Quoting ferpe (Reply 23):
the -800 is going further and further away from it's wing optimum which is around the -900 weights

Therefore, it seems that any attempt by Airbus to modify the A350 to compete with the B787-8 will require wing modification as well.

CM's opinion for Airbus

Quoting CM (Reply 18):
Then, over the next few years offer 1 or 2 reduced weight versions which have been re-optimized for lower operating weights. Perhaps a 6500nm - 7000nm version aircraft which takes out several tonnes and operate at much lower thrust.

is spot on. Anything else seems to be too much engineering and expense for very little gain.


25 TP313 : IMHO, the 350-800 will either: - Trade some of its "excessive" range for payload and be stretched by 1 or 2 LD-3 rows. - "Suffer" a bigger stretch an
26 Post contains images ferpe : This is exactly the development CM proposed in a 350-1000 thread, take the fuselage from the -1000 and weights, LG, engines etc from the -900. It tur
27 Stitch : Back in 2008, Airbus floated the idea of the "A350 Regional" that would not lower the OEW, but would reduce the MTOW by up to 30t to lower airport and
28 Post contains images ferpe : With a capacity north of 440 pax I guess this variant used the -1000 fuselage .
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