LAXDESI
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A350-10 Versus B773ER Updated Analysis

Sat May 21, 2011 11:49 pm

It's time to further update my model based on Airbus announcement that A350s OEW will likely come in higher at 2 tonne, and MTOW will be increased by 3 tonnes. Furthermore, MZFW will increase by 5 tonnes. Airbus also indicated that the range will remain the same, with a 1% fuel burn penalty.

General Specifications:
....................................A3510.......................B773ER
Fuselage Length..............242..........................242.5 feet
Fuselage Width.................19.6........................20.33
Wingspan.......................213..........................213
Wingarea......................4767.........................4605 sq. feet
Seats(3 class).................350..........................365 (210 lbs. per passenger/baggage)


MTOW.....................657,000....................775,000 lbs.
MZFW......................481,700....................524,000
OEW........................328,000...................370,000 (OEW for A3510 is my estimates)
MSP.........................153,700...................154,000
Design Range................8,000.....................7,930 nm (passenger only, and zero cargo)
List Price........................$299......................$284 million
Engine Thrust..............93,000...................115,500 lbf

Ratois
OEW/MTOW.....................0.50...........................0.48
MTOW/Wingarea............138............................168 (777 has much higher wingloading)
MTOW/Thrust....................3.53...........................3.35 (777 has more powerful engines normalised for MTOW)

Under the assumption of a 6,300 nm (HKG-LAX) mission at MTOW:

B773ER burns about 8,500 gallons more at a current cost of $26,000.
B773ER has the potential to carry about 13,000 lbs. additional cargo, and earn about $10,000 at 50% load factor.
B77ER has the potential to earn about $7,000 in additional 15 Y seat revenues at 70% load factor.

Overall, A350-10 has a net advantage of $9,000, or about $3 million annually for a 6,300nm mission.

Under the assumption of a 4,800 nm (NRT-LAX or LAX-LHR) mission at MTOW:

B773ER burns about 7,500 gallons more at a current cost of $23,000.
Minor difference in cargo capability, and therefore not material.
B77ER has the potential to earn about $6,000 in additional 15 Y seat revenues at 70% load factor.

Overall, A350-10 has a net advantage of $17,000, or about $6 million annually for a 4,800 nm mission.

If A350-10 comes in at above specs., the current B773ER will be at a competitive disadvantage.

B777ER has a payload advantage over A350-10 beyond 5,700 nm. So for operators like Cathay, B773ER has its appeal. One must also keep in mind $15 million list price advantage to B773ER.
 
LAXDESI
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RE: A350-10 Versus B773ER Updated Analysis

Sun May 22, 2011 1:11 am

In this post, I will compare a hypothetical B77W(10-abreast 390 seat NG) against the A350-10. I will assume a CFRP wing with similar wingarea as the current wing. Overall, I expect the NG to weigh about 5,000 lbs. less even with 25 more seats as the new CFRP wing(lighter by 8,000 lbs.) will offset the higher weight related to seats. I will assume an overall fuel burn that is 4% less(sfc and aero) than the current B77W.

General Specifications:
....................................A3510.......................B77W(NG)
Fuselage Length..............242..........................242.5 feet
Fuselage Width.................19.6........................20.33
Wingspan.......................213..........................213
Wingarea......................4767.........................4605 sq. feet
Seats(3 class).................350..........................390 (210 lbs. per passenger/baggage)


MTOW.....................657,000....................775,000 lbs.
MZFW......................481,700....................524,000
OEW........................328,000....................365,000 (OEW for A3510 and 77WNG are my estimates)
MSP.........................153,700....................154,000
Design Range................8,000.....................8,200 nm (passenger only, and zero cargo)
List Price........................$299......................$299 million (assume identical list price)
Engine Thrust..............93,000....................115,500 lbf

Under the assumption of a 6,300 nm (HKG-LAX) mission at MTOW:

B773ER burns about 7,000 gallons more at a current cost of $21,000.
B773ER has the potential to carry about 20,000 lbs. additional cargo, and earn about $14,000 at 50% load factor.
B77ER has the potential to earn about $16,000 in additional 40 Y seat revenues at 70% load factor.

Overall, B77W(NG) has a net advantage of $9,000, or about $3 million annually for a 6,300nm mission.

Under the assumption of a 4,800 nm mission at MTOW:

B773ER burns about 5,200 gallons more at a current cost of $15,600.
B77ER has the potential to earn about $13,000 in additional 40 Y seat revenues at 70% load factor.

A350-10 has $2,600 net trip advantage over B77w(NG).

Overall, a 10-abreast 77W(NG) should be able to compete under the specs. and assumptions I have laid out above on long and dense routes. However, the A350-10 has a lower trip cost and is to be preferred on routes which can not absorb the capacity of 77w(NG).
 
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RE: A350-10 Versus B773ER Updated Analysis

Sun May 22, 2011 1:11 am

Quoting LAXDESI (Thread starter):

If A350-10 comes in at above specs., the current B773ER will be at a competitive disadvantage.

This has been the general consensus that I have seen on this forum. I certainly expect it to turn out this way.

Quoting LAXDESI (Thread starter):
One must also keep in mind $15 million list price advantage to B773ER.

This is relatively small potatoes, and considering that planes do not get sold at list, the actual difference is much smaller. According to your figures, the savings from the A3510 would pay for this in as little as three years. And if fuel prices rise significantly the payback will be much quicker. The main advantage that the 77W will have in the next few years is availability. But without improvement or replacement its days are clearly numbered.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
 
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Stitch
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RE: A350-10 Versus B773ER Updated Analysis

Sun May 22, 2011 9:16 pm

For one carrier I know of, the OEW difference between the 777-300ER and A350-1000 is about 8 tons in favor of the A350-1000 with a seating difference of two less Economy Seats (both configured for 9-abreast).
 
WingedMigrator
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RE: A350-10 Versus B773ER Updated Analysis

Mon May 23, 2011 3:43 am

Quoting Stitch (Reply 3):
OEW difference between the 777-300ER and A350-1000 is about 8 tons

Well that would just about kill the A350-1000, wouldn't it? Eyeballing the numbers above, you'd need to trade that extra weight for ~11 tons less payload. That's a lot of payload.

Either that, or the brochure OEW figures have absolutely no connection with the porky interiors found in reality.
 
ferpe
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RE: A350-10 Versus B773ER Updated Analysis

Mon May 23, 2011 5:46 am

Quoting Stitch (Reply 3):
For one carrier I know of, the OEW difference between the 777-300ER and A350-1000 is about 8 tons in favor of the A350-1000

That would put the OEW of the 350-1000 at 160t and the OEW/MTOW at 0,54, one of the worst figures in the industry.

Based on their qouted payload-range figures the fullPnoC ratio is 11,1 % for 350-1000 and 11,2% for 77W, i.e. they have the same payload/MTOW ratio, i.e. no efficiency gain over 15 years of evolution?.

With this OEW the fuel burn advantage of the 350-1000 would be 31% but Lehay says it is 25% in the last intervju in Toulouse.

This OEW is very airline specific in that case, at the more normal 150t OEW to 298t MTOW the fuel burn fits with the stated 25% advantage for the 350-1000. I will stay with the typical 50% of MTOW for the OEW of the 350-1000 until we know more.
Non French in France
 
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Stitch
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RE: A350-10 Versus B773ER Updated Analysis

Mon May 23, 2011 4:20 pm

Quoting ferpe (Reply 5):
That would put the OEW of the 350-1000 at 160...

That matches the projected OEW.

[Edited 2011-05-23 10:14:20]
 
ferpe
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RE: A350-10 Versus B773ER Updated Analysis

Mon May 23, 2011 7:14 pm

Quoting Stitch (Reply 6):
That matches the projected OEW.

projected by whom, the said airline? There must be something wrong there, perhaps they said 18 tons, if this would be true nothing fits any longer, EKs complains with stated payload deficiencies etc.

Things like the above validates my emphasis for doing some simple check with ratios, for instance:

B starts with the troubled 788 and lands at a OEW/MTOW of about 50%, then they make the stretch and we assume they improve to even 48%.

A makes a very similar frame 4 years later and their first shot most likely lands pretty close to 50% (as per As reveal of MEWs in the Boeing weight problems). Then they make their optimised stretch and they duff down to an industry lowest 54%       . When we get such figures we must react and start to ask questions, wether it is my side of the Atlantic or not. These figures can simply not be based on the same comparison base.

[Edited 2011-05-23 12:26:19]

[Edited 2011-05-23 12:27:59]
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Stitch
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RE: A350-10 Versus B773ER Updated Analysis

Mon May 23, 2011 7:56 pm

Quoting ferpe (Reply 7):
projected by whom, the said airline?

Correct. With (effectively) the same number of seats, the A350-1000 has an 8t lower empty weight than the 777-300ER for this operator.
 
sunrisevalley
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RE: A350-10 Versus B773ER Updated Analysis

Tue May 24, 2011 2:35 am

Quoting WingedMigrator (Reply 4):
Either that, or the brochure OEW figures have absolutely no connection with the porky interiors found in reality.

A carrier who has the 77W fitted out at about 300 seats has a DOW of ~172t. Others at ~365 seats are at ~175t.
 
LAXDESI
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RE: A350-10 Versus B773ER Updated Analysis

Tue May 24, 2011 5:18 am

Quoting sunrisevalley (Reply 9):
A carrier who has the 77W fitted out at about 300 seats has a DOW of ~172t. Others at ~365 seats are at ~175t.

Your numbers are consistent with ferpe's rule of thumb of 50-60 kg per seat(65 X 50 kg = 3,250 kg).
 
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Stitch
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RE: A350-10 Versus B773ER Updated Analysis

Tue May 24, 2011 12:27 pm

NH's 247-seat "Inspiration of Japan" 77Ws have a higher DOW than AC's 349-seat 77Ws, but that is because of the much higher percentage of First and Business Class seating on the NH frame.
 
sunrisevalley
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RE: A350-10 Versus B773ER Updated Analysis

Tue May 24, 2011 3:17 pm

Quoting Stitch (Reply 11):
NH's 247-seat "Inspiration of Japan" 77Ws have a higher DOW than AC's 349-seat 77Ws, but that is because of the much higher percentage of First and Business Class seating on the NH frame.

My understanding of DOW is that it is OEW plus crew and catering. Sometime ago Zeke provided a break out of the weight of catering for each class of seating. In the example used by Stitch by my understanding , the higher weight of the NH frames would be a combination of spread between MEW and OEW plus spread between OEW and DOW.

a useful link is Which Is The Real Meaning Of OEW? (by Ferdinando Apr 1 2007 in Tech Ops)
 
ferpe
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RE: A350-10 Versus B773ER Updated Analysis

Tue May 24, 2011 7:28 pm

Quoting sunrisevalley (Reply 12):
My understanding of DOW is that it is OEW plus crew and catering.

The standard crew (the safety rule minimum) is part of OEW per definition. The extra crew which might contain more attendants and more exchange pilots as per airline standard would then land on the DOW side if I understand things right.
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RE: A350-10 Versus B773ER Updated Analysis

Wed May 25, 2011 6:29 pm

Quoting Stitch (Reply 11):
NH's 247-seat "Inspiration of Japan" 77Ws have a higher DOW than AC's 349-seat 77Ws, but that is because of the much higher percentage of First and Business Class seating on the NH frame.

Which goes to show that subtracting OEW (or DOW) and fuel burn-off from MTOW in order to determine useful payload is a nearly meaningless exercise. I've done it too, but with proper caveats... you need to keep in mind that every additional pound of interior is one less pound of available payload, and each airline will have a different trade-off for where that sweet spot might be. It would seem that the outcome of LAXDESI's revenue calculations would be highly sensitive to such OEW variations.

But again, this statement:

Quoting Stitch (Reply 8):
With (effectively) the same number of seats, the A350-1000 has an 8t lower empty weight than the 777-300ER for this operator.

doesn't pass the smell test, because the logical consequence is that the A350-1000 has no chance of competing against the 777-300ER if you substitute those values into LAXDESI's results. And yet "this operator" seems to have bought the A350-1000... What gives?
 
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Stitch
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RE: A350-10 Versus B773ER Updated Analysis

Wed May 25, 2011 7:01 pm

Quoting Stitch (Reply 8):
Correct. With (effectively) the same number of seats, the A350-1000 has an 8t lower empty weight than the 777-300ER for this operator.
Quoting WingedMigrator (Reply 14):
doesn't pass the smell test, because the logical consequence is that the A350-1000 has no chance of competing against the 777-300ER if you substitute those values into LAXDESI's results. And yet "this operator" seems to have bought the A350-1000... What gives?

While an A350 customer, this airline has not as yet ordered the A350-1000. And they appear to have access to OEM-provided data to work with and real route planning software to model on.

[Edited 2011-05-25 12:37:57]
 
LAXDESI
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RE: A350-10 Versus B773ER Updated Analysis

Thu Jun 09, 2011 6:00 pm

Cross posting from the following thread to keep track of recently announced changes to A350-10.
A350-1000's TrentXWB Gets 5,000lbs Extra Thrust (by PolymerPlane Jun 5 2011 in Civil Aviation)

Quoting sirtoby (Reply 13):
You can find more details here:

http://aeroturbopower.blogspot.com/2....html

General Specifications:
....................................A3510.......................B773ER
Fuselage Length..............242..........................242.5 feet
Fuselage Width.................19.6........................20.33
Wingspan.......................213..........................213
Wingarea......................4767.........................4605 sq. feet
Seats(3 class).................350..........................365 (210 lbs. per passenger/baggage)


MTOW.....................684,000....................775,000 lbs.
MZFW......................483,000...................524,000
OEW........................333,000...................370,000 (OEW for A3510 is my estimate)
MSP.........................150,000...................154,000
Design Range................8,500.....................7,930 nm (passenger only, and zero cargo)
List Price........................$299......................$284 million
Engine Thrust..............98,000...................115,500 lbf

Ratois
OEW/MTOW.....................0.49...........................0.48
MTOW/Wingarea............144............................168 (777 has much higher wingloading)
MTOW/Thrust....................3.49...........................3.35 (777 has more powerful engines normalised for MTOW)

I would expect the A350-10 to have about 30 Y seats less than the current 10-abreast 773ER in EK configuration(12F, 42J, 304Y). Going by A.net, EK leaves about 30-40 Y seats empty to make DXB-LAX(about 7,250nm) possible.

So on paper, the revised A350-10 would carry the same passenger payload as 77W but burning much less fuel on DXB-LAX/SFO. This should force Boeing to work on 77W(NG) sooner than they would like to.
 
LAXDESI
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RE: A350-10 Versus B773ER Updated Analysis

Fri Jun 10, 2011 9:18 pm

For future reference, let me post specs. for a hypothetical A350-11(80m).

General Specifications:
....................................A3511.......................B773ER
Fuselage Length..............262..........................242.5 feet
Fuselage Width.................19.6........................20.33
Wingspan.......................213..........................213
Wingarea......................4767.........................4605 sq. feet
Seats(3 class).................380..........................365 (210 lbs. per passenger/baggage)


MTOW.....................730,000....................775,000 lbs.
MZFW......................510,000...................524,000
OEW........................355,000...................370,000 (OEW for A3511 is my estimate)
MSP.........................155,000...................154,000
Design Range................8,500.....................7,930 nm (passenger only, and zero cargo)
List Price........................$320......................$284 million
Engine Thrust..............104,000...................115,500 lbf

Ratois
OEW/MTOW.....................0.48...........................0.48
MTOW/Wingarea............153............................168 (777 has 10% higher wingloading)
MTOW/Thrust....................3.51...........................3.35 (777 has 5% more powerful engines normalised for MTOW)

A350-11 could be Airbus's response to a possible B77W(10 abreast NG) from Boeing.

[Edited 2011-06-10 14:20:50]
 
incitatus
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RE: A350-10 Versus B773ER Updated Analysis

Sat Jun 11, 2011 4:36 pm

As the base A350 has not even flown, I expect the OEW of the A3510 to go up more, at least once. I say the first post is optimistic on the A3510 side, as the 77W is fully operational with proven performance. The second post seems optimistic on the NG version of the 77W. As Boeing looks at updating the 777, there will be weight-gaining enhancements as well, and shaving off 5000 lb of the OEW will be a struggle.

[Edited 2011-06-11 09:36:55]
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RE: A350-10 Versus B773ER Updated Analysis

Sat Jun 11, 2011 5:06 pm

Quoting LAXDESI (Thread starter):

Any reason why we need this thread when the thread you started on the same topic is still open ?

A350-10 Versus B773 ER Economic Analysis (by LAXDESI Jun 1 2008 in Tech Ops)

This is the third thread where you have rehashed the same discussion points.

Quoting incitatus (Reply 18):
I say the first post is optimistic on the A3510 side, as the 77W is fully operational with proven performance.

It is actually still tonnes higher than the spec OEW for the A350XWB-1000.
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LAXDESI
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RE: A350-10 Versus B773ER Updated Analysis

Sat Jun 11, 2011 6:42 pm

Quoting incitatus (Reply 18):
The second post seems optimistic on the NG version of the 77W. As Boeing looks at updating the 777, there will be weight-gaining enhancements as well, and shaving off 5000 lb of the OEW will be a struggle.

Depends on the size of proposed CFRP wing relative to the current wing. Others have speculated that the current wing is 10,000 lbs. heavier than it should be. I expect 77W(NG) to lose 10,000 lbs. with similarly sized CFRP wing as the current wing, and perhaps add about 5,000 lbs. with other enhancements.

On the other hand, there is news about new Al-Li material from Alcoa that could make it possible to lose some additional weight from the fuselage. Interesting times ahead.
 
parapente
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RE: A350-10 Versus B773ER Updated Analysis

Mon Jun 13, 2011 12:41 pm

Whilst I accept is is true.Does anybody know how 2 aircraft of equal length,that both seat 9 across,how one has a row and three quarters more people in it? (ie 15 pax)
 
MoltenRock
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RE: A350-10 Versus B773ER Updated Analysis

Mon Jun 13, 2011 2:25 pm

Didn't anyone bother to read the Alcoa release? Those weight savings were for short range / narrow body aircraft only.

http://www.alcoa.com/global/en/news/...eID=20110609005855en&newsYear=2011
 
LAXDESI
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RE: A350-10 Versus B773ER Updated Analysis

Mon Jun 20, 2011 3:12 am

New estimates and comparison based on the following link. The link also suggests that A350-10 will burn 25% less fuel than 77W on a 4,000 nm mission.
http://www.flightglobal.com/articles...d-to-2017-as-rolls-raises-xwb.html

General Specifications:
....................................A3510.......................B773ER
Fuselage Length..............242..........................242.5 feet
Fuselage Width.................19.6........................20.33
Wingspan.......................213..........................213
Wingarea......................4767.........................4605 sq. feet
Seats(3 class).................350..........................365 (210 lbs. per passenger/baggage)


MTOW.....................679,000....................775,000 lbs.
MZFW......................492,000...................524,000
OEW........................338,000...................370,000 (OEW for A3510 is my estimate)
MSP.........................154,000...................154,000
Design Range................8,400.....................7,930 nm (passenger only, and zero cargo)
List Price........................$309......................$284 million
Engine Thrust..............97,000...................115,500 lbf

Ratois
OEW/MTOW.....................0.50...........................0.48
OEW/MZFW......................0.69...........................0.71(consistent with lighter material of A350-10)
MZFW/MTOW....................0.72...........................0.67(consistent with lower fuel burn of a newer aircraft)
MTOW/Wingarea............143............................168 (777 has much higher wingloading)
MTOW/Thrust....................3.50...........................3.35 (777 has more powerful engines normalised for MTOW)

Using my model, here's what I get for a 4,000 nm trip:

A350-10 burns about 17,480 gallons of fuel, and B77W burns about 22,740 gallons. Based on above estimates, my model yields 23% lower trip fuel burn(compared to 25% in the link above). There is only a slight difference in payload capability. On a per seat basis, the revised A350-10 has a 20% lower GSM(gallon seat mile).

A350-10 0.0125 GSM(gallon seat mile) and 0.0568 GTM(gallon ton mile)
B77W 0.0156 GSM and 0.0738 GTM

As per my model, A350-10 saves about $16,000 in fuel cost. B77W has the potential to earn about $5,000 in additional passenger revenue(15 seats X 70% X $500), leaving A350-10 with a net benefit of nearly $11,000 per 4,000 nm trip.
 
hal9213
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RE: A350-10 Versus B773ER Updated Analysis

Tue Jun 21, 2011 2:54 pm

Quoting parapente (Reply 21):
Whilst I accept is is true.Does anybody know how 2 aircraft of equal length,that both seat 9 across,how one has a row and three quarters more people in it? (ie 15 pax)

The 77W figures with typical 365 pax are for 10 abreast. That being said, 15 pax difference seems a bit low. Lets take EK for example. I will try and calculate a possible configuration for EK (currently 354/364 seats).

Currently, six 7-abreast J-rows, and either 2x6 F-Seats or 2x4 Suites, rest is economy (304/310 seats, 29 full rows, more narrow rows in back) Lets suppose, they keep their philosophy of 8/12F and 42J (Thats what they have in everything but the A380).
F would stay the same in length (The suites fit fine in their A345 too). J is already narrow, so they would need to do 7 rows of 6-abreast with the current seats (=1 additional J-row). That takes away 2,5 Y-rows. Now assuming 2 less Y-rows and 27 seats less for all full Y-rows, 47 less Y-seats.
So EK would have a config of 8/42/257 for a long-haul-version 350-1000, totalling 307 pax.

Assuming, they will introduce A380-style J-seats: A "set" has a very similar length to the 777-style seats, however would feature 8-abreast (4+4 staggered actually) on the same cabin length due to design (Lets assume they use the couple of inch extra width just for comfort, as in the F-Suites).
We could have 5 J-rows instead, accounting for 5 more Y-rows than before, or 5.5 J-Rows for, lets say, 3 more Y-rows, that makes either 8/40/302 = 350 or 8/44/284 = 336.

Thus, the 15-pax or less difference could only be achieved with the 380-style J-seats, otherwise it would be more like
a 47 seats difference.
Aaaaah, now I nearly finished this post, and noticed, the 350-1000 is only going to have 8 doors????    So, more seats afterall...   
 
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Stitch
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RE: A350-10 Versus B773ER Updated Analysis

Tue Jun 21, 2011 5:21 pm

Quoting hal9213 (Reply 24):
Lets take EK for example. I will try and calculate a possible configuration for EK (currently 354/364 seats).

EK themselves have said the A350-1000 will seat 317 using the same seats found in their 354-seat 777-300ER.
 
PolymerPlane
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RE: A350-10 Versus B773ER Updated Analysis

Tue Jun 21, 2011 6:17 pm

Quoting hal9213 (Reply 24):
The 77W figures with typical 365 pax are for 10 abreast.

Wrong.

http://www.boeing.com/commercial/airports/acaps/777rsec2.pdf

page 19/ page 13 on the pdf
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LAXDESI
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RE: A350-10 Versus B773ER Updated Analysis

Thu Jun 23, 2011 8:41 pm

Thanks to mffoda, I got a link to another blog where there was discussion on the revised specs. for A350-10. It is suggested in the comments section that the A350-10 is about 11,000 lbs. overweight. Based on numbers from this blog, let me present a new set of specs.

General Specifications:
....................................A3510.......................B773ER
Fuselage Length..............242..........................242.5 feet
Fuselage Width.................19.6........................20.33
Wingspan.......................213..........................213
Wingarea......................4767.........................4605 sq. feet
Seats(3 class).................350..........................365 (210 lbs. per passenger/baggage)


MTOW.....................679,000....................775,000 lbs.
MZFW......................485,000...................524,000
OEW........................343,900...................370,000 (OEW for A3510 is my estimate)
MSP.........................141,100...................154,000
Design Range................8,400.....................7,930 nm (passenger only, and zero cargo)
List Price........................$309......................$284 million
Engine Thrust..............97,000...................115,500 lbf

Ratois
OEW/MTOW.....................0.50...........................0.48
OEW/MZFW......................0.71...........................0.71
MZFW/MTOW....................0.71...........................0.67(consistent with lower fuel burn of a newer aircraft)
MTOW/Wingarea............143............................168 (777 has much higher wingloading)
MTOW/Thrust....................3.50...........................3.35 (777 has more powerful engines normalised for MTOW)

Using my model, here's what I get for a 4,000 nm trip:
B77W has the potential to carry 9,000 lbs. additional cargo, and has a 15 seat advantage in 9-abreast, but burns much less fuel.

As per my model, A350-10 saves about $16,000 in fuel cost. B77W has the potential to earn about $5,000 in additional passenger revenue(15 seats X 70% X $500), and about $5,000 in cargo revenue, leaving A350-10 with a net benefit of nearly $6,000 per 4,000 nm trip.

For operators like EK with 10-abreast Y layout, the seat advantage is about 37 seats, and that tilts the advantage slightly to B77W for a 4,000 nm mission.

On a mission length of 6,300 nm(HKG-LAX), A350-10 would burn about 9,000 gallons less(25%) than B77W. B77W would have a cargo advantage of 3,000 lbs., and 15 seats in 3 class format. My model suggests that A350-10 will have an advantage of nearly $15,000 over B77W(9-abreast) for such a mission.

On a mission length of 7,250 nm(DXB-LAX), EK leaves about 35 seats empty in its 10-abreast configuration. A350-10 should be able to fly with the same no. of passengers while burning nearly 25% less fuel.
 
PolymerPlane
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RE: A350-10 Versus B773ER Updated Analysis

Thu Jun 23, 2011 10:36 pm

Quoting LAXDESI (Reply 27):
On a mission length of 7,250 nm(DXB-LAX), EK leaves about 35 seats empty in its 10-abreast configuration. A350-10 should be able to fly with the same no. of passengers while burning nearly 25% less fuel.

Do you know EK's DOW for 77W? how can you say with certainty that A350-10 can do the mission without knowing the weight of EK's interior? Once you start mentioning specific airlines, the OEW becomes meaningless. On paper, with "standard" 77W, EK does not have to leave anybody to complete 7,250 NM mission.
One day there will be 100% polymer plane
 
LAXDESI
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RE: A350-10 Versus B773ER Updated Analysis

Fri Jun 24, 2011 12:50 am

Quoting PolymerPlane (Reply 28):
how can you say with certainty that A350-10 can do the mission without knowing the weight of EK's interior? Once you start mentioning specific airlines, the OEW becomes meaningless. On paper, with "standard" 77W, EK does not have to leave anybody to complete 7,250 NM mission.

I do not know the weight of EK 77W that are used on DXB-LAX mission. I am going by what I have read on A.net from other posters.

The distance flown on the most recent EK 77W DXB-LAX flight is 7,335 nm(GC distance 7,250 nm). It does seem to track the GC route. B77W design range is at 7,930 nm with 365 passengers at 9-abreast in Y. As EK's 77W is at 10-abreast in Y, I am fairly certain EK's 77W OEW is higher than that of standard 77W due to the heavier F and J seats used by most operators relative to standard configuration.
 
PolymerPlane
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RE: A350-10 Versus B773ER Updated Analysis

Fri Jun 24, 2011 4:38 am

Quoting LAXDESI (Reply 29):
I do not know the weight of EK 77W that are used on DXB-LAX mission. I am going by what I have read on A.net from other posters.

The distance flown on the most recent EK 77W DXB-LAX flight is 7,335 nm(GC distance 7,250 nm). It does seem to track the GC route. B77W design range is at 7,930 nm with 365 passengers at 9-abreast in Y. As EK's 77W is at 10-abreast in Y, I am fairly certain EK's 77W OEW is higher than that of standard 77W due to the heavier F and J seats used by most operators relative to standard configuration.

Then how do you declare A350-10 can do the job with the sampe pax count in EK configuration?
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LAXDESI
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RE: A350-10 Versus B773ER Updated Analysis

Fri Jun 24, 2011 5:10 am

Quoting PolymerPlane (Reply 30):
Then how do you declare A350-10 can do the job with the sampe pax count in EK configuration?

As I said earlier, I am going by A.net posters(who I respect) who have indicated that it leaves passengers behind. They could be wrong, and in that case my analysis of A350/B77W wrt EK and DXB-LAX sector does not hold.

I hope someone in know can clear this up.
 
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Stitch
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RE: A350-10 Versus B773ER Updated Analysis

Fri Jun 24, 2011 6:00 am

EK can be trading passengers for revenue cargo.

I've hard from EK fleet ops people that they keep sending the 77L to Houston because of the freight demand.
 
hal9213
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RE: A350-10 Versus B773ER Updated Analysis

Fri Jun 24, 2011 10:10 am

Somebody a long time ago posted here on A.net, that EK has four 77W (that somebody even posted the regs) which it specifically ordered from Boeing to have 1 Ton extra MTOW to be used for the SFO/LAX routes.
Is there anything to that statement?
 
sunrisevalley
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RE: A350-10 Versus B773ER Updated Analysis

Fri Jul 01, 2011 7:20 pm

Quoting hal9213 (Reply 33):
Is there anything to that statement?

I believe there is . Somewhere someone posted the registration numbers. I would put EK's 77W's at ~174 to 175t although with the seating limitation at about 320 they could go out lighter because of less catering.
 
astuteman
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RE: A350-10 Versus B773ER Updated Analysis

Sat Jul 02, 2011 7:21 am

Quoting sunrisevalley (Reply 34):
I would put EK's 77W's at ~174 to 175t although with the seating limitation at about 320 they could go out lighter because of less catering.

Those numbers are the ones I've heard

Quoting PolymerPlane (Reply 28):
On paper, with "standard" 77W, EK does not have to leave anybody to complete 7,250 NM mission.

As above, the Dry operating weight of EK's 773ER's is said to be some 9 tonnes over the ACAP spec (some 5 tonnes of which will be catering equipement, which both OEM's seem to leave out of their calcs for convenience sake)

That extra weight brings the range with nominal pax down to about the c. 7 350Nm of DXB-LAX.

Then don't forget that this is a "still-air" distance. But the air between Dubai and Los Angeles is rarely still.

EK operate 4 x 773ER which are (IIRC) 3t heavier MTOW (352t v 349t) than their others, specifically for this route. And as Sunrisevalley says, they limit the flight to 320 seats



Quoting Stitch (Reply 32):
EK can be trading passengers for revenue cargo.

On DXB-LAX, I've been told that the 320 seat limitation is there because it may allow a very small (as in single digit tonnes) cargo allowance, if the headwinds allow. But they don't always

Rgds
 
ferpe
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RE: A350-10 Versus B773ER Updated Analysis

Sat Jul 02, 2011 12:43 pm

Quoting astuteman (Reply 35):
EK operate 4 x 773ER which are (IIRC) 3t heavier MTOW (352t v 349t) than their others, specifically for this route. And as Sunrisevalley says, they limit the flight to 320 seats

The not so good thing about the 77W is that it lacks fuel space, it is fuel capacity limited well above it's design range, thus to leave of payload weather pax or cargo does not bring that much. Funny that B does not offer extra tankage for this frame (or do they?).
Non French in France
 
sunrisevalley
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RE: A350-10 Versus B773ER Updated Analysis

Sat Jul 02, 2011 2:10 pm

What interests me about EK's DXB-LAX operations is that more than 50% of the elapsed times as recorded by FlightAware for the most recent 13 days in June are one hour or more less than the 16hr.30m. timetable times with all but one of the balance at least 30-min. less. On the face of it , based on fuel burn according to Zeke of about 8t an hour , payloads could have been anywhere from 4t to 8t better than allowed for in the timetable times which is the equiv. of ~ 2 to 4 PMC pallets at 180kg/m^3.
I wonder if EK limit the passenger load and adjust the freight load on the day?
 
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Stitch
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RE: A350-10 Versus B773ER Updated Analysis

Sat Jul 02, 2011 6:33 pm

Quoting Stitch (Reply 32):
EK can be trading passengers for revenue cargo.
Quoting astuteman (Reply 35):
On DXB-LAX, I've been told that the 320 seat limitation is there because it may allow a very small (as in single digit tonnes) cargo allowance, if the headwinds allow. But they don't always

I can believe that. I've heard from EK Flight Planning folks that DXB-JFK has to offload 1.7 tons of cargo if the temps are in the mid-to-upper 30's at departure time.

Still, EK clearly see more pax demand than cargo on the route, since 320 passengers is almost 60 more than the 777-200LR can carry, even though the 77L can go out with full passengers and full cargo bays.



Quoting ferpe (Reply 36):
The not so good thing about the 77W is that it lacks fuel space, it is fuel capacity limited well above it's design range, thus to leave of payload weather pax or cargo does not bring that much. Funny that B does not offer extra tankage for this frame (or do they?).

No they do not. I imagine there is nothing stopping Boeing from putting in the extra tanks like the 777-200LR can have, but I am guessing that even though the 77W is fuel volume limited at design range with design payload not enough airlines are interested in trading even more payload weight for additional fuel weight.
 
astuteman
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RE: A350-10 Versus B773ER Updated Analysis

Sun Jul 03, 2011 8:31 am

Quoting ferpe (Reply 36):
The not so good thing about the 77W is that it lacks fuel space, it is fuel capacity limited well above it's design range, thus to leave of payload weather pax or cargo does not bring that much. Funny that B does not offer extra tankage for this frame (or do they?).

Although at 7 800Nm fuel limit range, I don't think it's a huge constraint in most cases

Quoting Stitch (Reply 38):
Still, EK clearly see more pax demand than cargo on the route, since 320 passengers is almost 60 more than the 777-200LR can carry, even though the 77L can go out with full passengers and full cargo bays.

  
I'd assume they know what they're doing  

Rgds
 
hal9213
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RE: A350-10 Versus B773ER Updated Analysis

Sun Jul 03, 2011 12:55 pm

Quoting astuteman (Reply 35):
EK operate 4 x 773ER which are (IIRC) 3t heavier MTOW (352t v 349t) than their others, specifically for this route.

Do you (or anybody) have the regs?
I cant find the post anymore.
 
sunrisevalley
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RE: A350-10 Versus B773ER Updated Analysis

Sun Jul 03, 2011 1:28 pm

Quoting astuteman (Reply 39):
I'd assume they know what they're doing

They seem to be one of the few that are on top of all the controllable aspects of their business   
 
mercure1
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RE: A350-10 Versus B773ER Updated Analysis

Mon Jul 04, 2011 9:10 pm

Quoting hal9213 (Reply 33):
1 Ton extra MTOW to be used for the SFO/LAX routes.

a6-ecl, -ecm, -ecn, -eco, -ecp @ 351,534 KG

most are 349.2t or 340.1t
 
CM
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RE: A350-10 Versus B773ER Updated Analysis

Thu Jun 28, 2012 3:37 pm

Not wanting to derail the 787 fuel burn thread where this topic was originally raised, I am resurrecting this thread as a good spot to get my question answered.

The statement was made in reply 81 of this Civ-Av thread (http://www.airliners.net/aviation-forums/general_aviation/read.main/5498220/#100), that Boeing never qualifies what they mean when they claim the 787-8 is 20% more fuel efficient than the 767-300ER.

Quoting zeke (Reply 81):
When I read the claims Boeings was making about the 787 relative to the 767, I could only think they were meaning the 787 with the design payload over the design range vs the 767 with the design payload over the design range, they were never specific, this in my view always gave them some wiggle room.

I provided the rule-set used by Boeing when they made that claim in rely 92 of that thread, but then went looking for what rules Airbus uses when making the A350 is 25% more efficient than the 777" claim - I can't find any.





Does anyone know on what basis (mission rules) Airbus makes this claim? The fact Airbus does not indicate the minor model for any aircraft (A350-900? 777-200ER?) and that they are claiming a 25% improvement in both trip and seat fuel (which means the aircraft must have identical seat counts) raises some pretty fundamental questions, but maybe I'm missing something. Can anyone provide the rules Airbus is using to backstop this "25%" claim?

Thanks!

CM
 
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zeke
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RE: A350-10 Versus B773ER Updated Analysis

Thu Jun 28, 2012 4:04 pm

Quoting CM (Reply 43):
that Boeing never qualifies what they mean when they claim the 787-8 is 20% more fuel efficient than the 767-300ER.

This typical of how Boeing presented the numbers, they did not even confirm it was the 767

http://i15.photobucket.com/albums/a357/thezeke/787/db71ff2a.png

Quoting CM (Reply 43):

Does anyone know on what basis (mission rules) Airbus makes this claim? The fact Airbus does not indicate the minor model for any aircraft (A350-900? 777-200ER?) and that they are claiming a 25% improvement in both trip and seat fuel (which means the aircraft must have identical seat counts) raises some pretty fundamental questions, but maybe I'm missing something. Can anyone provide the rules Airbus is using to backstop this "25%" claim?

Aircraft type/sub model, range, and seat configuration were all listed when the aircraft was launched. Do an internet search for a file called "further_pre_a350_xwb_launch_2006.pdf" you will see where this was listed in table form. This was discussed at great length at the time.
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CM
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RE: A350-10 Versus B773ER Updated Analysis

Thu Jun 28, 2012 6:27 pm

Quoting zeke (Reply 44):
search for a file called "further_pre_a350_xwb_launch_2006.pdf" you will see where this was listed in table form.

Thanks for that!

(here's the link, BTW, for anyone who wants to reference the material being discussed - Airbus_A350_XWB_Launch_Pitch)

In the referenced presentation:
  • The Airbus claims are based on comparison of aircraft on different missions (each on its design range mission)

  • The Airbus claims are based on comparison of aircraft at different comfort levels

A quick dissection of the +25% and -25% number (Airbus uses it both ways) is instructive: +25% fuel burn for the competition in the tabular format turned into -25% fuel burn advantage for the A350 in the above Airbus slides when no context is provided. Those two are not the same claim. If we assume for a moment Airbus' +30% / +25% block fuel per seat numbers for the 777-200ER / -300ER are correct, then do the math to get to an A350 advantage number (the minus number) we can see Airbus is playing pretty loose with the "minus 25%" claim, even using their own fuel burn assumptions and seat rules:
  • A350-900 vs 777-200ER = +30% block fuel per seat for the 777-200ER works out to -23% per seat & -20% per trip for the A350-900, given Airbus' seat rules

  • A350-1000 vs 777-300ER = +25% block fuel per seat for the 777-300ER works out to -20% per seat & -23% per trip for the A350-1000, given Airbus' seat rules

Given the tabular data in the Airbus pitch you referenced, none of the per/seat or per/trip comparisons add up to a -25% figure, even when using Airbus' assumptions on seat count. At best, the -25% number can be described as a generic and generous representation of how the A350 will compare to the 777. At worst, it is patently misleading, particularly when it when it is presented on a fan chart indicating this is a savings (minus 25%) in both trip and per seat fuel. The number becomes further useless when you consider the comparison is of aircraft performance on different mission lengths configured to different interior rules.
 
ferpe
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RE: A350-10 Versus B773ER Updated Analysis

Sat Jun 30, 2012 7:08 am

In line with the 3510 vs 777 discussion here the continuation of another question from the 787 fuel burn thread which contained both 787, 350 and 777 comparisions:

http://www.google.fr/url?sa=t&rct=j&...hArnWz-nYa_piRgWWX74rQMVrA&cad=rja

Could you CM explain how B came the the conclusions on slides 12 and 27 of this presentation:

http://i298.photobucket.com/albums/mm262/ferpe_bucket/788vs358comparision201206.jpg


How can 7800nm be construed as the 358s range when A says 8500nm?


http://i298.photobucket.com/albums/mm262/ferpe_bucket/777vs3510comparision201206.jpg

How can 7775nm be construed as the 3510s "design range" when A says 8400nm?
Non French in France
 
CM
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RE: A350-10 Versus B773ER Updated Analysis

Sun Jul 08, 2012 6:54 am

Quoting ferpe (Reply 46):
Could you CM explain how B came the the conclusions on slides 12 and 27 of this presentation:

Hi Ferpe. Sorry for the delayed response. Here it is in a nutshell...

A wise company would book keep at least 3 separate analysis for any competitor aircraft which has not yet flown. Each analysis has its place in trying to understand what a future competitor product may be. Each represents an equally possible outcome from a new airplane development program.

One analysis would be done with the assumption the competitor advertized mission will be met. With the mission as a given, and making (usually generous) assumptions about technology level of the aircraft, its expected aero, structural and propulsive efficiency, performance engineers can then back out to what they believe the competitor aircraft design weights would need to be in order for for that technology level aircraft to be able to make the mission. This is the most capable aircraft you could expect to be delivered.

The second analysis would be done using the competitor advertised design weights (as appears to be the case in these charts). With the design weights as a given, performance engineers can then take the same assumptions as above about the technology level of the aircraft and back out to what they believe the mission capability would be for that technology level aircraft at the given design weights. This is the most economical aircraft you could expect to be delivered.

These first two analysis represent the poles of what you could expect to enter the marketplace, both in terms of capability and economics.

The third analysis is a blend of the first two extremes. This third analysis represents a more balanced and more likely approach to designing a new aircraft, where both economics and mission performance are both traded away putting the final product into some middle point. This type of analysis is more tricky as you now have to guess how your competitor values different aspects of performance, as these values will ultimately shape the final product.

The charts you highlighted above both clearly state Boeing has performed the analysis using Airbus' spec MTOW. This means that for the advertized operating weights Boeing believes the technology being used will not deliver the advertized mission capability. Boeing is showing what they believe will be the most efficient but least capable version of the A350 on these charts. They used the same analysis on slide 16 where they compared operating costs, so the comparison aircraft is consistent throughout the deck, even though showing analysis from method 1 or 3 in the op-cost comparison would have shown an A350 outcome with relatively worse economics. The method is sound. What is worth discussing are the conclusions.

[Edited 2012-07-08 00:11:28]

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