Okcflyer wrote:

What would the trip fuel had been for the A359 for the above trip photo-documented?

To carry 47.6 tonnes of payload over a distance of 4000 nm, the A359 would burn around 10% less fuel (source flysmart A359 inflight performance CI120 with TOW of 235 tonnes 4000 nm ISA conditions, RVSM even optimum profile), however you would not be able to seat 415 pax with the same configuration in the A359 so the question is rather academic.

Okcflyer wrote:

enzo011 wrote:

Okcflyer wrote:

The A35K's strongest competitor is the A359 (especially later builds). What would the trip fuel had been for the A359 for the above trip photo-documented?

Per several analysis, there is very little, if any, per-seat fuel burn advantage of the K over the 9. Without a unit cost advantage, the primary reason to buy the more expensive stretch (K model) is if the carrier's network needs additional capacity.

Further, how do engine maintenance costs vary between the 9 and K?

The sales data suggest the K's economic advantages over the 9 are usually not justified.

But isn't that true for all models? If you don't need the extra seats the A359 has over the 789 you should look at the 789 instead. Is this is not true for aviation as a whole?

Typically the larger airplanes have a lower CASM (cost per available seat mile).Basically, the cost per seat decreases as the capacity increases.

What’s very unique to the A359/A35K case is that the unit seat costs are effectively the same despite the A35K being larger and more expensive.

In the case of the 787, for any route the 78J can fly, the per-seat costs are materially less than the 789 on the same route. This increases profitability when those other seats are used.
This IS NOT the case for the A35K.

(Ignore revenue management for this ... that actually further helps the smaller airplanes).

The idea from Airbus, and the demand from their customers as they made the change late, was to have two sizes of plane with otherwise identical abilities. The 787-10 serves a different market than the 789, shorter routes (with short being very, very relative here), the A359/K serve the same market, just that you shift the Ks to where the demand is currently higher, and the 9 to where it is lower. So more of a revenue up than cost down approach to a family.

With the 781 making up ~14% of 787 orders, the A35K making up 18% and considering it was available earlier in the program relative to the first variant it seems both approaches are about equally valid and successful.

best regards
Thomas

any previous discussion about 280t 74m length A35J?

Armadillo1 wrote:

any previous discussion about 280t 74m length A35J?

The have been previous threads on the A350-1100 eg viewtopic.php?t=607299

Armadillo1 wrote:

any previous discussion about 280t 74m length A35J?

Looking at the latest version of Airbus AIRCRAFT CHARACTERISTICS - AIRPORT AND MAINTENANCE PLANNING, the A35K currently has 9 different Weight Variants and some of them are around the 280 ton MTOW

WV005 > MTOW 270 ton
WV007 > MTOW 260 ton
WV009 > MTOW 290 ton

Looking at MTOW the A35K varies from 260 ton to 316 ton and the A359 varies from 217 ton to 280 ton (and EASA TCDS mention another variant with MTOW 210 ton for the A359)

Okcflyer wrote:

enzo011 wrote:

Okcflyer wrote:

The A35K's strongest competitor is the A359 (especially later builds). What would the trip fuel had been for the A359 for the above trip photo-documented?

Per several analysis, there is very little, if any, per-seat fuel burn advantage of the K over the 9. Without a unit cost advantage, the primary reason to buy the more expensive stretch (K model) is if the carrier's network needs additional capacity.

Further, how do engine maintenance costs vary between the 9 and K?

The sales data suggest the K's economic advantages over the 9 are usually not justified.

But isn't that true for all models? If you don't need the extra seats the A359 has over the 789 you should look at the 789 instead. Is this is not true for aviation as a whole?

Typically the larger airplanes have a lower CASM (cost per available seat mile).Basically, the cost per seat decreases as the capacity increases.

What’s very unique to the A359/A35K case is that the unit seat costs are effectively the same despite the A35K being larger and more expensive.

In the case of the 787, for any route the 78J can fly, the per-seat costs are materially less than the 789 on the same route. This increases profitability when those other seats are used.
This IS NOT the case for the A35K.

(Ignore revenue management for this ... that actually further helps the smaller airplanes).

What is so special about the 35K that it does not follow the falling CASM logic according to you?

CRJockey wrote:

Okcflyer wrote:

enzo011 wrote:

But isn't that true for all models? If you don't need the extra seats the A359 has over the 789 you should look at the 789 instead. Is this is not true for aviation as a whole?

Typically the larger airplanes have a lower CASM (cost per available seat mile).Basically, the cost per seat decreases as the capacity increases.

What’s very unique to the A359/A35K case is that the unit seat costs are effectively the same despite the A35K being larger and more expensive.

In the case of the 787, for any route the 78J can fly, the per-seat costs are materially less than the 789 on the same route. This increases profitability when those other seats are used.
This IS NOT the case for the A35K.

(Ignore revenue management for this ... that actually further helps the smaller airplanes).

What is so special about the 35K that it does not follow the falling CASM logic according to you?

Because it doesn’t lose capability (payload/range) as a simple stretch would.

Fred


Sent from my iPhone using Tapatalk

flipdewaf wrote:

CRJockey wrote:

Okcflyer wrote:

Typically the larger airplanes have a lower CASM (cost per available seat mile).Basically, the cost per seat decreases as the capacity increases.

What’s very unique to the A359/A35K case is that the unit seat costs are effectively the same despite the A35K being larger and more expensive.

In the case of the 787, for any route the 78J can fly, the per-seat costs are materially less than the 789 on the same route. This increases profitability when those other seats are used.
This IS NOT the case for the A35K.

(Ignore revenue management for this ... that actually further helps the smaller airplanes).

What is so special about the 35K that it does not follow the falling CASM logic according to you?

Because it doesn’t lose capability (payload/range) as a simple stretch would.

Fred


Sent from my iPhone using Tapatalk

Thanks. So the weight gain to retain capability does fully offset any CASM advantage? Interesting.

CRJockey wrote:

flipdewaf wrote:

CRJockey wrote:

What is so special about the 35K that it does not follow the falling CASM logic according to you?

Because it doesn’t lose capability (payload/range) as a simple stretch would.

Fred


Sent from my iPhone using Tapatalk

Thanks. So the weight gain to retain capability does fully offset any CASM advantage? Interesting.

Probably not fully, but a large chunk of it. Per m2 of Cabin area the A35k is a touch lighter than the A359, but having essentially the same wing, higher weights and induced drag increasing with the square of weight you won´t get much of fuel savings. You still just need one cockpit crew to fly it, one slot for departure and landing and all the little things where costs are essentially per flight, so CASM will still be better, but not by much compared to going from the 789 to a 781. But you get ~14% more cabin floor and 22% more room for cans and pallets downstairs, so you can extract quite a bit more revenue from the flight too.

best regards
Thomas

CRJockey wrote:

flipdewaf wrote:

CRJockey wrote:

What is so special about the 35K that it does not follow the falling CASM logic according to you?

Because it doesn’t lose capability (payload/range) as a simple stretch would.

Fred


Sent from my iPhone using Tapatalk

Thanks. So the weight gain to retain capability does fully offset any CASM advantage? Interesting.

It’s a rather rare case of bigger isn’t much better.

Keep in mind the A35K’s MTOW is 39T greater. That’s almost 14% increase. The 35K has a *longer* range than the shorter A359.

-K gets a 6-wheel boggie (although rumor is that it’s not much heavier than the -9’s), trailing edge extension on the wings (slightly lower aspect ratio), reworked engines with 13klbs additional thrust each, slightly worse SFC.

All together, it’s really over capable for 99% of its missions.

what about 772ER vs 77W?

if you say 35K overcapable (with range?) so 359 must be as well to.

Armadillo1 wrote:

what about 772ER vs 77W?

if you say 35K overcapable (with range?) so 359 must be as well to.

The 77E vs 77W is the OPPOSITE case. The 77W features a half-generation newer engines, significant L/D reduction due to raked wingtips, and other PIPs / enhancements.

The 77W barely uses more fuel than a 77E for the same payload over the same range (especially once >4000nm).

Therefore, the additional 33ft of cabin length comes almost "free", and is easy to offset by additional revenue potential. It's CASM is significant less (15% or so) compared to 77E.

The A35K is opposite. It's trip fuel cost increase is nearly equal to the cabin size increase. The CASM is effectively the same between the two models.

Okcflyer wrote:

Armadillo1 wrote:

what about 772ER vs 77W?

if you say 35K overcapable (with range?) so 359 must be as well to.

The 77E vs 77W is the OPPOSITE case. The 77W features a half-generation newer engines, significant L/D reduction due to raked wingtips, and other PIPs / enhancements.

The 77W barely uses more fuel than a 77E for the same payload over the same range (especially once >4000nm).

Therefore, the additional 33ft of cabin length comes almost "free", and is easy to offset by additional revenue potential. It's CASM is significant less (15% or so) compared to 77E.

The A35K is opposite. It's trip fuel cost increase is nearly equal to the cabin size increase. The CASM is effectively the same between the two models.

6000 nm trip, close to zero average wind, 48t payload - 95t fuel burn for 77e and 104 for 77w. That is close enough to 10%. If that qualifies as "barely more fuel", the a35k also uses barely more fuel than the a359.

Okcflyer wrote:

enzo011 wrote:

Okcflyer wrote:

The A35K's strongest competitor is the A359 (especially later builds). What would the trip fuel had been for the A359 for the above trip photo-documented?

Per several analysis, there is very little, if any, per-seat fuel burn advantage of the K over the 9. Without a unit cost advantage, the primary reason to buy the more expensive stretch (K model) is if the carrier's network needs additional capacity.

Further, how do engine maintenance costs vary between the 9 and K?

The sales data suggest the K's economic advantages over the 9 are usually not justified.

But isn't that true for all models? If you don't need the extra seats the A359 has over the 789 you should look at the 789 instead. Is this is not true for aviation as a whole?

Typically the larger airplanes have a lower CASM (cost per available seat mile).Basically, the cost per seat decreases as the capacity increases.

What’s very unique to the A359/A35K case is that the unit seat costs are effectively the same despite the A35K being larger and more expensive.

In the case of the 787, for any route the 78J can fly, the per-seat costs are materially less than the 789 on the same route. This increases profitability when those other seats are used.
This IS NOT the case for the A35K.

(Ignore revenue management for this ... that actually further helps the smaller airplanes).

A slight difference though: the 78X has less range, whereas the A35K is nearly (equally) as capable as the A359, the 78X is much less capable than the 789.

Okcflyer wrote:

The 77E vs 77W is the OPPOSITE case. The 77W features a half-generation newer engines, significant L/D reduction due to raked wingtips, and other PIPs / enhancements.

The 77W barely uses more fuel than a 77E for the same payload over the same range (especially once >4000nm).

Therefore, the additional 33ft of cabin length comes almost "free", and is easy to offset by additional revenue potential. It's CASM is significant less (15% or so) compared to 77E.

The A35K is opposite. It's trip fuel cost increase is nearly equal to the cabin size increase. The CASM is effectively the same between the two models.

I think the problem is that the A35K is the 773 and not the 77W of the family. It has the same technologies of the base model where the 77W had years to wait for, as you mention, newer engine technology and other enhancements. But the A35K isn't competing against the A359 which is what you were comparing, it is competing for sales in the area where the 77W sits currently. Yes, there will be cases where the A359 will be better for airlines over the A35K, but that is still a A350 sale for Airbus if that is the case.

Here's a thought - Ory-Ptp is 4,194nm, or near the 4,000nm max range of the A321XLR with full passenger load. So:
The A35K carries 415 pax in relatively dense configuration (94% of exit limit) 4,194nm burning 51.5t of fuel, or 0.0296kg fuel/pax/nm (excuse the mixed units)
The A321XLR has 39,500l fuel capacity, or maybe 35,500l ex reserves, or 28,542kg, so can carry 230 pax (94% of 244 exit limit) 4,000 miles using 28.542tonnes or 0.0310 kg fuel/pax/nm, or about 5% more than the A35K

Does that make sense?

In addition, the flight crew cost will be greater for the A321XLR (2 pilots for 230 pax vs 2 pilots for 415), so a little more in the A35K favour. The A330neo and 787 will presumably be slightly better over the shorter range (the A35K having more modern design/engines, but too much range)

This broadly aligns with my thought that the A321XLR will offer similar economics to wide bodies, but not a step change (slightly less good, but with half the pax, it can run on thinner routes or higher frequency). on this basis, it would seem likely that the A321XLR will find a place in the medium range between secondary cities, but will not be a game changer.

thoughts?

MrHMSH wrote:

Okcflyer wrote:

enzo011 wrote:

But isn't that true for all models? If you don't need the extra seats the A359 has over the 789 you should look at the 789 instead. Is this is not true for aviation as a whole?

Typically the larger airplanes have a lower CASM (cost per available seat mile).Basically, the cost per seat decreases as the capacity increases.

What’s very unique to the A359/A35K case is that the unit seat costs are effectively the same despite the A35K being larger and more expensive.

In the case of the 787, for any route the 78J can fly, the per-seat costs are materially less than the 789 on the same route. This increases profitability when those other seats are used.
This IS NOT the case for the A35K.

(Ignore revenue management for this ... that actually further helps the smaller airplanes).

A slight difference though: the 78X has less range, whereas the A35K is nearly (equally) as capable as the A359, the 78X is much less capable than the 789.

As far as I can see the the A35K is more capable all round vs the A359. It carries more stuff further than the A359. The payload range of the 789 crosses that of the 781 however as far as I can tell the 359 at no point matches that of the A35k.

Fred


Sent from my iPhone using Tapatalk

Carmitage wrote:

Here's a thought - Ory-Ptp is 4,194nm, or near the 4,000nm max range of the A321XLR with full passenger load. So:
The A35K carries 415 pax in relatively dense configuration (94% of exit limit) 4,194nm burning 51.5t of fuel, or 0.0296kg fuel/pax/nm (excuse the mixed units)
The A321XLR has 39,500l fuel capacity, or maybe 35,500l ex reserves, or 28,542kg, so can carry 230 pax (94% of 244 exit limit) 4,000 miles using 28.542tonnes or 0.0310 kg fuel/pax/nm, or about 5% more than the A35K

Does that make sense?

In addition, the flight crew cost will be greater for the A321XLR (2 pilots for 230 pax vs 2 pilots for 415), so a little more in the A35K favour. The A330neo and 787 will presumably be slightly better over the shorter range (the A35K having more modern design/engines, but too much range)

This broadly aligns with my thought that the A321XLR will offer similar economics to wide bodies, but not a step change (slightly less good, but with half the pax, it can run on thinner routes or higher frequency). on this basis, it would seem likely that the A321XLR will find a place in the medium range between secondary cities, but will not be a game changer.

thoughts?

How did you arrive at the A350-100 numbers ? 51.5T fuel for 42T payload over a 10 hour flight seems really really optimistic. @zeke or other resident A35K pilots can chime in here with real data.

sabby wrote:

How did you arrive at the A350-100 numbers ? 51.5T fuel for 42T payload over a 10 hour flight seems really really optimistic. @zeke or other resident A35K pilots can chime in here with real data.

On the previous page there is a cockpit photo, 51.2 tonnes over 8:11 for the sector.

Carmitage wrote:

Here's a thought - Ory-Ptp is 4,194nm, or near the 4,000nm max range of the A321XLR with full passenger load. So:
The A35K carries 415 pax in relatively dense configuration (94% of exit limit) 4,194nm burning 51.5t of fuel, or 0.0296kg fuel/pax/nm (excuse the mixed units)
The A321XLR has 39,500l fuel capacity, or maybe 35,500l ex reserves, or 28,542kg, so can carry 230 pax (94% of 244 exit limit) 4,000 miles using 28.542tonnes or 0.0310 kg fuel/pax/nm, or about 5% more than the A35K

zeke wrote:

sabby wrote:

How did you arrive at the A350-100 numbers ? 51.5T fuel for 42T payload over a 10 hour flight seems really really optimistic. @zeke or other resident A35K pilots can chime in here with real data.

On the previous page there is a cockpit photo, 51.2 tonnes over 8:11 for the sector.

Thank you zeke. I didn't validate Carmitage's stated distance as it turns out ORY-PTP is 3648nm not 4194nm as they claimed. So I considered a 10 hour flight for the A350. If I assume A321XLR should take around 9:15 hours for the same route, which would mean around 10% less fuel that Carmitage's calculation so actually 5% better fuel cost per person. All of this is actually kind of moot as the entire point of using A321XLR against a bigger widebody is when demand is much lower so what really matters is revenue and trip costs. There's also the fact that at 9 hours with 24T, we are talking about extreme ends of the A321XLR design where it is mot optimized. Pretty much all the widebody aircraft are optimized for 3500-7000nm (depending on aircraft) ranges so of course at those conditions, the advantage of A321XLR would diminish quite quickly.

It depends on many variables of course, but you can probably assume for a typical mission and payload 6.2 to 6.6 tons per hour of fuel burn. For the cockpit photo referenced above fuel burn would have averaged just under 6.3 tons per hour for an 8.11 hour mission. Relative to most 77W missions my back of envelope calculations would say the A350-1000 has between 18% to 21% better fuel burn than the 77W.

Zeke, are you looking at the LRC numbers for the A350 on your trips? What are you getting? I looked at ours, and out to three places LRC is identical at optimum altitude, .796M. So if the ole 73
has those numbers easily available in the FMC and on the flight deck cards, I assume the A350 does too. .86+?

On 744 we could take 465pax and with max payload of 56 tons and fly for 11hours, burning on average around 10,5t/h on on such a flight. Don't just do raw comparison without comparing actual payload and capability.

Dufo wrote:

On 744 we could take 465pax and with max payload of 56 tons and fly for 11hours, burning on average around 10,5t/h on on such a flight. Don't just do raw comparison without comparing actual payload and capability.

12 hrs is within the max structural payload range for the A350-1000, therefore capable of over 70 tonnes of payload over that range. The 744 has a lot more floor area and capable of carrying a more passengers. Under floor the 744 will carry 10 pallets (5 in front and 5 in the rear), the A350-1000 can carry 14 (8 in the front, 6 in the rear).

I also flew the 744 years ago, I wouldn’t see an average of 10.5 tonnes per hour at high weights, starting off around 13 tonnes per hour going down to around 9 tonnes per hour towards top of descent, average over 11 tonnes per hour.

Zeke? What is the A350's LRC at optimum altitude? Or are you still claiming it is .86+ and/or LRC at optimum altitude varies?

http://youtu.be/FebToTrmd2Y?t=109 Sam Chui has a very detailed video showing the cockpit from a LAX-DOH flight with the a35k. Tow 304.5t trip fuel 100.6t air distance 7100 zfw 194t. The payload should be around 40t given that the QR a35k has the qsuite thus is heavier than usual. http://vdocuments.site/sfo-dxb.html has a trip data from an ek 77w flying almost the exact distance with a similar payload(ek 77w empty weight varies a lot but 175t-177t is a figure I hear). Trip fuel is 122.6t and trip time 25m longer. Note both these are pre flight data but should be quite accurate which means the 77w burned 22% more trip fuel than the a35k for a similar air distance and payload.

A35K (as with all new/more efficient designs) has largest efficiency improvement at max range window. The 77W is burning more fuel to carry more fuel. This is how the gains multiply at the edge cases.

I’m curious as to the improvement at a more normal range. 4500nm / 10 hour sector for similar payload. I would expect it’s close to 15% for older 77W’s. Closer to 12% compared to 2014+ models.

Okcflyer wrote:

A35K (as with all new/more efficient designs) has largest efficiency improvement at max range window. The 77W is burning more fuel to carry more fuel. This is how the gains multiply at the edge cases.

I’m curious as to the improvement at a more normal range. 4500nm / 10 hour sector for similar payload. I would expect it’s close to 15% for older 77W’s. Closer to 12% compared to 2014+ models.

When you break down the figures given by xwb565 using Breguet and build them back up again at 4500nm the difference is 19% higher for the 77W vs A35k. (16% if you invert the reference).

Fred


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Sam Chui published this today in a Instagram Story regarding Qatar first full vaccinated flight on board an A35K A7-ANF

https://instagram.com/samchui?igshid=1h91kdad0rtym

DOW: 160438 Kg

Wow ....that is 8-9t heavier than other a35k but the qsuite is a winner with passengers so worth it I guess.