jtdieffen wrote:

I'm surprised by what look like a fifth set of exit doors. I thought Boeing had removed a pair from the original spec. Is this an optional feature or perhaps a glimpse into future model(s)?

Yes, Boeing deleted the Type A overwing exit found on the 777-300ER and the 777-9's exits are all fore or aft of the wing.

The 777-9 is offered with four exit configurations:

1) Four Type A (for an Exit Limit of 440 seats)
2) Three Type A and One Type C (for an Exit Limit of 385 seats)
3) Three Type A and Two Type C (for an Exit Limit of 440 seats)
4) Four Type A and One Type C (for an Exit Limit of 475 seats)

(Doors are per side so total exists would be twice that)

Thanks, Stitch! That's really interesting! Will be interesting to see who's choosing which configs.

Stitch wrote:

The 777-9 is offered with four exit configurations:

1) Four Type A (for an Exit Limit of 440 seats)
2) Three Type A and One Type C (for an Exit Limit of 385 seats)
3) Three Type A and Two Type C (for an Exit Limit of 440 seats)
4) Four Type A and One Type C (for an Exit Limit of 475 seats)

Here's something I never really understood, perhaps you could help with it:

What would be an airline's incentive to take less than the max available doors for allowing max seating?
Even if they don't plan on using it, one would think that it'd affect potential resale/re-lease.

My guess is that different configurations amount to differing (higher) weights, and that additional doors may also "block" what could've been a potential row of seats-- but I figure the latter could be rectified by the amount of extra seats allowed.

Anyone?

LAX772LR wrote:

Here's something I never really understood, perhaps you could help with it: What would be an airline's incentive to take less than the max available doors for allowing max seating? Even if they don't plan on using it, one would think that it'd affect potential resale/re-lease.

I believe most 777-300ER operators configure their frames with less than 440 seats. Outside of ANA's and JL's domestic shuttles, the highest-density configuration I can think of off the top of my head is AF's 468. As such, the fifth Type A door is mostly just taking up space that could be used for seats or more galley / lavatory space. Therefore, I believe most 777-9 operators will take the four Type A configuration.

EK's highest-density configuration is 428 and they have said their 777-9's will max out at 440 seats, which would be covered under a 4xType A configuration.

LAX772LR wrote:

My guess is that different configurations amount to differing (higher) weights...

Eliminating the overwing Type A exit is said to reduce the weight by around 450kg / 1000 pounds. In a four-door configuration, the distance between the 2nd and 3rd doors would be 60 feet, which meets certifying authority maximums.

LAX772LR wrote:

Stitch wrote:

The 777-9 is offered with four exit configurations:

1) Four Type A (for an Exit Limit of 440 seats)
2) Three Type A and One Type C (for an Exit Limit of 385 seats)
3) Three Type A and Two Type C (for an Exit Limit of 440 seats)
4) Four Type A and One Type C (for an Exit Limit of 475 seats)

Here's something I never really understood, perhaps you could help with it:

What would be an airline's incentive to take less than the max available doors for allowing max seating?
Even if they don't plan on using it, one would think that it'd affect potential resale/re-lease.

My guess is that different configurations amount to differing (higher) weights, and that additional doors may also "block" what could've been a potential row of seats-- but I figure the latter could be rectified by the amount of extra seats allowed.

Anyone?

I can answer that. Each seating setup changes the distribution of seats. At each type C, the pitch must be 36" (going from memory, so when someone quotes another number, they are right). 4 Type A slightly reduces business class seating. So airlines with large business cabins go for Three type A doors to improve revenue.

4 Type A and a C is only useful on very high density configurations and most airlines do not require this. It adds weight and maintenance costs. Type C can be retrofitted, so airlines that do not require it for initial configurations will not order them. The resale value improvement is less than the cost to operate for 12 years.

Lightsaber

PHBVF wrote:

OldAeroGuy wrote:

WIederling wrote:

If that ever catches on you will have the Boeing PR people wring their hands to no end.

As long as it's unofficial, I think they'd love it. The connotation is good and there is no bad PR.

Besides, wasn't "LONGER" one of the A340-600's catch words painted on the demo airplane?

Actually it was Longer - Larger - Fart

I thought I was maturing until I saw that picture

Stitch wrote:

jtdieffen wrote:

I'm surprised by what look like a fifth set of exit doors. I thought Boeing had removed a pair from the original spec. Is this an optional feature or perhaps a glimpse into future model(s)?

Yes, Boeing deleted the Type A overwing exit found on the 777-300ER and the 777-9's exits are all fore or aft of the wing.

The 777-9 is offered with four exit configurations:

1) Four Type A (for an Exit Limit of 440 seats)
2) Three Type A and One Type C (for an Exit Limit of 385 seats)
3) Three Type A and Two Type C (for an Exit Limit of 440 seats)
4) Four Type A and One Type C (for an Exit Limit of 475 seats)

(Doors are per side so total exists would be twice that)

Just so we're on the same page, what does a Type C exit look like? I assume Type A is a standard door. Is Type C like an overwing 737-style exit? Would Type B be like the R1 door on the MD8X? Is there a Type D?

BWIAirport wrote:

Just so we're on the same page, what does a Type C exit look like? I assume Type A is a standard door. Is Type C like an overwing 737-style exit? Would Type B be like the R1 door on the MD8X? Is there a Type D?

A Type A is a floor-level exit with a rectangular opening of not less than 42 inches wide by 72 inches high.

A Type C is a floor-level exit with a rectangular opening of not less than 30 inches wide by 48 inches high. It appears to be that carriers who use Door 2L on the A321 for boarding it is a Type C, as it is larger than the Type I used on the other exits. I believe most narrowbodies use Type I exits.

The overwing exit on the 737NG/MAX is known as a Type III - this type is a rectangular opening of not less than 20 inches wide by 36 inches high and with a step-up inside the airplane of not more than 20 inches. If the exit is located over the wing, the step-down outside the airplane may not exceed 27 inches.

Type B is a floor-level exit with a rectangular opening of not less than 32 inches wide by 72 inches high. I am not sure what frames use them (if any).

(Information taken from FAR Sec. 25.807 — Emergency exits)

Stitch wrote:

BWIAirport wrote:

Just so we're on the same page, what does a Type C exit look like? I assume Type A is a standard door. Is Type C like an overwing 737-style exit? Would Type B be like the R1 door on the MD8X? Is there a Type D?

A Type A is a floor-level exit with a rectangular opening of not less than 42 inches wide by 72 inches high.

A Type C is a floor-level exit with a rectangular opening of not less than 30 inches wide by 48 inches high. It appears to be that carriers who use Door 2L on the A321 for boarding it is a Type C, as it is larger than the Type I used on the other exits. I believe most narrowbodies use Type I exits.

The overwing exit on the 737NG/MAX is known as a Type III - this type is a rectangular opening of not less than 20 inches wide by 36 inches high and with a step-up inside the airplane of not more than 20 inches. If the exit is located over the wing, the step-down outside the airplane may not exceed 27 inches.

Type B is a floor-level exit with a rectangular opening of not less than 32 inches wide by 72 inches high. I am not sure what frames use them (if any).

(Information taken from FAR Sec. 25.807 — Emergency exits)

Thanks for the information!

lightsaber wrote:

LAX772LR wrote:

Stitch wrote:

The 777-9 is offered with four exit configurations:

1) Four Type A (for an Exit Limit of 440 seats)
2) Three Type A and One Type C (for an Exit Limit of 385 seats)
3) Three Type A and Two Type C (for an Exit Limit of 440 seats)
4) Four Type A and One Type C (for an Exit Limit of 475 seats)

Here's something I never really understood, perhaps you could help with it:

What would be an airline's incentive to take less than the max available doors for allowing max seating?
Even if they don't plan on using it, one would think that it'd affect potential resale/re-lease.

My guess is that different configurations amount to differing (higher) weights, and that additional doors may also "block" what could've been a potential row of seats-- but I figure the latter could be rectified by the amount of extra seats allowed.

Anyone?

I can answer that. Each seating setup changes the distribution of seats. At each type C, the pitch must be 36" (going from memory, so when someone quotes another number, they are right). 4 Type A slightly reduces business class seating. So airlines with large business cabins go for Three type A doors to improve revenue.

4 Type A and a C is only useful on very high density configurations and most airlines do not require this. It adds weight and maintenance costs. Type C can be retrofitted, so airlines that do not require it for initial configurations will not order them. The resale value improvement is less than the cost to operate for 12 years.

Lightsaber

I suspect the most common option will be A-A-A-A and A-A-C-A as alluded to above.

Simply because Door 2 will be the most common "general" door for boarding (you would not want a type C there) and from what I understand the first and last set of doors are fixed as full type A doors. (Per Boeing ACAPS). It remains to be seen if the "optional service door" (type C) would actually be useful for servicing, thus why 4 full type A doors seems the logical choice, with the supplementary A-A-A-C-A and A-A-C-C-A config restricted to ultra high density configs. (Personally, apart from the Boeing test frames, I doubt we will see anything but A-A-A-A in the real world)

Some more photos of the static test frame







https://twitter.com/BoeingEurope/status ... 4432857088

The third pic really shows off the wingtips in their folded up position. They almost look like super massive winglets.

If I understood correctly winglet are more efficient at cruise and for such an LR bird I'd think you don't want a "flat" wing once folding tips are deployed, right ?
Or the tip device is just missing as not needed for fatigue testing ?

Grizzly410 wrote:

If I understood correctly winglet are more efficient at cruise and for such an LR bird I'd think you don't want a "flat" wing once folding tips are deployed, right ?
Or the tip device is just missing as not needed for fatigue testing ?

The bit pointing up is the folding wingtip. My understanding is the motors and such for folding aren't installed but the wingtips are still needed for the non flying tests. So they're installed. To move them up or down you'll need to use outside mechanisms.

My understanding for winglets vs raked wingtips is that if you've got the space to spare then the raked wingtips are preferable. But if you've got space restrictions then winglets are better than nothing. So for the B777X they're going for the best of both worlds, raked wingtips for flight and folding mechanism to fit the space restrictions. I expect these sorts of mechanisms to appear in narrowbodies in the not too distant future.

Grizzly410 wrote:

If I understood correctly winglet are more efficient at cruise and for such an LR bird I'd think you don't want a "flat" wing once folding tips are deployed, right ?
Or the tip device is just missing as not needed for fatigue testing ?

The raked wingtip (while flat) adds 85% of the wingtip's length into the effective wing span. A blended wingtip (folded) adds 45% of the wingtip's length into the effective wing span.

In other words, the effective wingspan after unfolding the wing tip would be 64.8 (the length of the wing) + 0.85 * 7 (effect of span increase due to raked wingtip) = 70.75 m
While the wingtips are folded, the effective wing span would be 64.8 + 0.45 * 7 = 67.95. Those are of course rough estimates. The flat wing in this case adds 3m to the effective span over the folded (kinda blended) wingtip.

ZaphodHarkonnen wrote:

My understanding for winglets vs raked wingtips is that if you've got the space to spare then the raked wingtips are preferable. But if you've got space restrictions then winglets are better than nothing

True, the raked wingtip adds more to the wingspan for a given length and weight of a wingtip device, but it has a negative side to it, it wastes horizontal wingspan while doing so. On the other hand, a blended wingtip extends upwards, so it eventually does not waste any span. The folding wingtip of the 77X fixes this problem for the raked wingtip as it keeps it at 64.75 span limit when needed.

That's why I always wondered why the 777 (non -X model) was designed with a raked wingtip if it's limited at the 64.75m span. This 64.75m span of the 777 is actually wing+(0.8*wingtip length), so its effective wingspan is actually somewhere between 63-64m. That could've been more if they went for a blended wingtip back in the day.

Eyad89 wrote:

Grizzly410 wrote:

If I understood correctly winglet are more efficient at cruise and for such an LR bird I'd think you don't want a "flat" wing once folding tips are deployed, right ?
Or the tip device is just missing as not needed for fatigue testing ?

The raked wingtip (while flat) adds 85% of the wingtip's length into the effective wing span. A blended wingtip (folded) adds 45% of the wingtip's length into the effective wing span.

In other words, the effective wingspan after unfolding the wing tip would be 64.8 (the length of the wing) + 0.85 * 7 (effect of span increase due to raked wingtip) = 70.75 m
While the wingtips are folded, the effective wing span would be 64.8 + 0.45 * 7 = 67.95. Those are of course rough estimates. The flat wing in this case adds 3m to the effective span over the folded (kinda blended) wingtip.

ZaphodHarkonnen wrote:

My understanding for winglets vs raked wingtips is that if you've got the space to spare then the raked wingtips are preferable. But if you've got space restrictions then winglets are better than nothing

True, the raked wingtip adds more to the wingspan for a given length and weight of a wingtip device, but it has a negative side to it, it wastes horizontal wingspan while doing so. On the other hand, a blended wingtip extends upwards, so it eventually does not waste any span. The folding wingtip fixes this problem for the raked wingtip as it keeps it at 64.75 span limit when needed.

That's why I always wondered why the 777 was designed with a raked wingtip if it's limited at the 64.75m span. This 64.75m span of the 777 is actually wing+(0.8*wingtip length), so its effective wingspan is actually somewhere between 63-64m. That could've been more if they went for a blended wingtip back in the day.

You can look at it the other way round. A raked wingtip is optimal as long as you do not hit the limits of the airport categories, C less than 36 m, D less than 52 m, E less than 65 m and F less than 80 m.

If you want to extend the effective span, as opposed to the geometric span, past the category limits, you can either go up (or down) with a blended winglet or go passed the limit and do a raked folding wingtip.

So the 777-8/9 goes well past the category limit and folds the raked tip. The 787 is well below the limit with a raked tip. The A350 and A330neo go geometrically right to the limit and extend the effective span past the limit with the sharklet or blended winglet, however you want to call it.

Here's an article with a picture of the folding wing-tip that will actually fly. Lots more pictures in the article itself. Cool.

https://www.bizjournals.com/seattle/news/2018/10/03/boeing-777x-jet-folding-wingtips-everett.html?ana=yahoo&yptr=yahoo

http://aviationweek.com/propulsion/ge9x ... tification tells us "GE9X For Boeing 777X Delivered For Final Flying Testbed Certification" and that everythings on track for EIS. I've posed more details in tech-ops at viewtopic.php?f=5&t=1385673&p=20773469#p20773469 ....

So when is rollout of the first flight test plane expected for?

If an airline leases the B777x,not purchase,are they able to retrofit their cabins after 5-10years without attachments from the lessor?emirates did that to their b777, but i think they are purchased.is it for airlines more attractive to purchase a new aircraft,than to retrofit them after 10years?or to buy them out from the leasing agreement with low price,and then retrofit them?maybe its more profitable,i don't know.can someone explain about aircraft leasing?i already search through wikipedia,but its not well-explained.

A few photos of the wings being attached to the first flight test aircraft









https://twitter.com/BoeingAirplanes/sta ... 7644118016

SleeplessInZh wrote:

If an airline leases the B777x,not purchase,are they able to retrofit their cabins after 5-10years without attachments from the lessor?emirates did that to their b777, but i think they are purchased.is it for airlines more attractive to purchase a new aircraft,than to retrofit them after 10years?or to buy them out from the leasing agreement with low price,and then retrofit them?maybe its more profitable,i don't know.can someone explain about aircraft leasing?i already search through wikipedia,but its not well-explained.

If an airline leases a new aircraft on a 12 year lease, end of lease (EOL) negotiations will usually start in Y10 if the leasee has plans to do anything other than return the aircraft at the end of the 12th year.

The EOL balloon payment, usually includes the leasee making a payment to the leasor sufficient to replace the interior, or they negotiate a discount of the EOL payment based on the value applied to the current interior.

If a leasee of a new aircraft on a 12 year lease wants to replace the interior say at the halfway mark, and plans to return the aircraft to the leasor at the end of the lease, they will try to negotiate a new (higher) EOL interior valuation with the leasor, before embarking on the changes.

Changing a complete interior is pretty unusual mid lease, because it puts the leasor in a strong bargaining position at end of lease. A case of the leasee showing their hand, for example increasing the odds the lease will be extended.

qf789 wrote:

A few photos of the wings being attached to the first flight test aircraft

All I can say is Wow!

That is the the finest example of aviation porn I've seen in a long time!

The flight test wings look so much more buttoned up than the stress test wings.

The pictures show the significance of the folding wingtips beautifully.

Think of how much money those photos capture.

Billions for the design, and the building of the wing factory, and these early examples.

More billions for the rest of the flight test squad and the flight tests themselves.

We're lucky to witness this next step in aviation.

Does the GE9X have the saw-figure trailing edge, same as the 747-8, 787 and 737MAX? I've seen renderings with and without it, and e.g. the flying testbed was without it.

I just find it very cool personally, and would be a shame if they don't include it.

Carlos01 wrote:

Does the GE9X have the saw-figure trailing edge, same as the 747-8, 787 and 737MAX? I've seen renderings with and without it, and e.g. the flying testbed was without it.

I just find it very cool personally, and would be a shame if they don't include it.

From the pictures of the engine on the GE testbed, it does not appear so.

Carlos01 wrote:

Does the GE9X have the saw-figure trailing edge, same as the 747-8, 787 and 737MAX? I've seen renderings with and without it, and e.g. the flying testbed was without it.

I just find it very cool personally, and would be a shame if they don't include it.

GE ditched the Chevrons a while ago. They claimed they've achieved the desired noise levels without the feature. Production units will now have a "regular" trailing edge fan cowl. Also, the chevrons weigh more so they'll be saving some weight on each engine.

Well if they just bolted on the wings, I figure we're still a few months from a formal rollout, let alone first flight

Sooner787 wrote:

Well if they just bolted on the wings, I figure we're still a few months from a formal rollout, let alone first flight

I don't recall, and can't find, if Boeing has given any more specific target than 1Q, 2019, so they've got as much as 5 months to go before first flight, unless the schedule slides.

Thank you smartplane!
I'd like to know more about 'leasing agreements' (not found in wiki) and you gave a good reply.

PHL9R wrote:

GE ditched the Chevrons a while ago. They claimed they've achieved the desired noise levels without the feature. Production units will now have a "regular" trailing edge fan cowl. Also, the chevrons weigh more so they'll be saving some weight on each engine.

Chevrons also creates a little drag, - so I am happy to see they can achieve noise levels without.



KR/
Airboe

I could not see this posted, but Boeing shared this picture. looks really good

Anyone compare and contrast the 777 and 777x on wikipedia. Im looking it over and Im finding inconsistencies.

The fuel capacity of the 777x is 52k vs 48k gallons. Yet with this extra fuel it only flies 200nm further...

Then there is the overall seating capacity. The 777x is 4meters longer yet the 3-class seating capacity is 16 seats less.

Whats the deal here. Burns more fuel and carries fewer people??!

Yes I know the seating numbers are estimations and carriers will do what they want. And range is not entirely accurate either... I get all that.

But still...

danj555 wrote:

Anyone compare and contrast the 777 and 777x on wikipedia. Im looking it over and Im finding inconsistencies.

The fuel capacity of the 777x is 52k vs 48k gallons. Yet with this extra fuel it only flies 200nm further...

Then there is the overall seating capacity. The 777x is 4meters longer yet the 3-class seating capacity is 16 seats less.

Whats the deal here. Burns more fuel and carries fewer people??!

Yes I know the seating numbers are estimations and carriers will do what they want. And range is not entirely accurate either... I get all that.

But still...

Can't answer all of the points but yes the -9X is longer than -300 and -8X longer than -200 so the capacity is larger in the -9X than -300/300ER. Maybe the new "typical 3-class" seating is more premium heavy or the business class takes up more room than older products. That is all I can think of.

As for tanks I don't know but the fuel economy is better. i.e. The 8X/9X will burn less per mile than old 200/300. Range of the -8X should be longer than -200LR and the Range of the 9X again slightly longer than -300ER.

danj555 wrote:

The fuel capacity of the 777x is 52k vs 48k gallons. Yet with this extra fuel it only flies 200nm further...

Neither aircraft can fill its tanks with a full brochure-configuration passenger load. The 777-300ER will burn more fuel on the brochure mission than the 777-9. The 777-9 will rarely use its full fuel capacity--the capacity is intended for a 777-8 flying ULH missions.

Then there is the overall seating capacity. The 777x is 4meters longer yet the 3-class seating capacity is 16 seats less.

Boeing has been adjusting its reference density downward with newer widebody products, to stay consistent with the practice of the largest airline customers. Airlines have been devoting more space to Business, and Business products have become a bit less space-efficient.

With the same space allocation, the 777-9 will typically hold 25-30 more passengers than the 777-300ER.

Carlos01 wrote:

Does the GE9X have the saw-figure trailing edge, same as the 747-8, 787 and 737MAX? I've seen renderings with and without it, and e.g. the flying testbed was without it.

I just find it very cool personally, and would be a shame if they don't include it.

the chevrons kill noise at significant cost. You are better of without them ( if you can meet the noise requirements.)

danj555 wrote:

Anyone compare and contrast the 777 and 777x on wikipedia. Im looking it over and Im finding inconsistencies.

The fuel capacity of the 777x is 52k vs 48k gallons. Yet with this extra fuel it only flies 200nm further...

Then there is the overall seating capacity. The 777x is 4meters longer yet the 3-class seating capacity is 16 seats less.

Whats the deal here. Burns more fuel and carries fewer people??!

Yes I know the seating numbers are estimations and carriers will do what they want. And range is not entirely accurate either... I get all that.

But still...

The ACAP documents are usually far better for comparison than wikipedia
https://www.boeing.com/commercial/airports/plan_manuals.page

Oykie wrote:

I could not see this posted, but Boeing shared this picture. looks really good

In this picture it appears the tail is similar to the 787 tail now....was this apart of the changes or am I just seeing things ?

TropicalSky wrote:

Oykie wrote:

I could not see this posted, but Boeing shared this picture. looks really good

In this picture it appears the tail is similar to the 787 tail now....was this apart of the changes or am I just seeing things ?

No, you are right the tail is a 787 style "shark fin"

Sent from my LG-H870 using Tapatalk

mullac30 wrote:

TropicalSky wrote:

Oykie wrote:

I could not see this posted, but Boeing shared this picture. looks really good

In this picture it appears the tail is similar to the 787 tail now....was this apart of the changes or am I just seeing things ?

No, you are right the tail is a 787 style "shark fin"

Sent from my LG-H870 using Tapatalk

Boeing sure did put a lot of things learnt on the 787 program back into the 777.....will it also have the luminar flow feature that's on 789&10 tail ?

TropicalSky wrote:

Boeing sure did put a lot of things learnt on the 787 program back into the 777.....will it also have the luminar flow feature that's on 789&10 tail ?

Wasn't that discontinued on the 787 already? "Too much hassle".

danj555 wrote:

The fuel capacity of the 777x is 52k vs 48k gallons. Yet with this extra fuel it only flies 200nm further...

The range isn't simply determined by the maximum fuel capacity (even though it could be a limiting factor at times). it is rather determined by the payload/range chart for a specific payload. That chart gets its shape from the maximum structural payload of the aircraft, maximum zero fuel weight, and maximum take off weight.

MTOW: 351t (same as 77W)
MZFW: 255t (18t heavier than 77W)
MSP: still unknown

Once MSP is announced, we will see why it is given the range it has for a certain payload.

Lufthansa News
‏
Cuenta verificada

@lufthansaNews

Lufthansa Boeing Airplanes
Congrats! A few more weeks, then it's our turn. We're looking forward to our 34 Boeing 777-9s.

The later said "We have ordered 20 aircraft and firmly reserved 14 more (reconfirmable)" .

chiki wrote:

The later said "We have ordered 20 aircraft and firmly reserved 14 more (reconfirmable)" .

In September 2013, the Lufthansa AG Board "committed" to 34 frames (of which 20 were firm orders via a transfer of deposits from their 20 747-8 Purchase Options) with up to an additional 30 purchase rights / options.

I'm guessing Lufthansa has something similar to what American did with the 787-9 and those 14 never-firmed frames have guaranteed production slots assigned to them that Lufthansa must confirm a certain period of time ahead (AA's window was 18 months prior) or they become available for another customer.

Stitch wrote:

chiki wrote:

The later said "We have ordered 20 aircraft and firmly reserved 14 more (reconfirmable)" .

In September 2013, the Lufthansa AG Board "committed" to 34 frames (of which 20 were firm orders via a transfer of deposits from their 20 747-8 Purchase Options) with up to an additional 30 purchase rights / options.

I'm guessing Lufthansa has something similar to what American did with the 787-9 and those 14 never-firmed frames have guaranteed production slots assigned to them that Lufthansa must confirm a certain period of time ahead (AA's window was 18 months prior) or they become available for another customer.

OT...been a while...good to see you back at this forum, Stitch.

Eyad89 wrote:

danj555 wrote:

The fuel capacity of the 777x is 52k vs 48k gallons. Yet with this extra fuel it only flies 200nm further...

The range isn't simply determined by the maximum fuel capacity (even though it could be a limiting factor at times). it is rather determined by the payload/range chart for a specific payload. That chart gets its shape from the maximum structural payload of the aircraft, maximum zero fuel weight, and maximum take off weight.

MTOW: 351t (same as 77W)
MZFW: 255t (18t heavier than 77W)
MSP: still unknown

Once MSP is announced, we will see why it is given the range it has for a certain payload.

Wait, so its weight without fuel is higher, it carries more fuel (which adds weight), and its take off weight it the same??

Something has to give. That must mean that payload takes a hit.
Yet it can carry more cargo and pax. What am I missing here?

danj555 wrote:

Eyad89 wrote:

danj555 wrote:

The fuel capacity of the 777x is 52k vs 48k gallons. Yet with this extra fuel it only flies 200nm further...

The range isn't simply determined by the maximum fuel capacity (even though it could be a limiting factor at times). it is rather determined by the payload/range chart for a specific payload. That chart gets its shape from the maximum structural payload of the aircraft, maximum zero fuel weight, and maximum take off weight.

MTOW: 351t (same as 77W)
MZFW: 255t (18t heavier than 77W)
MSP: still unknown

Once MSP is announced, we will see why it is given the range it has for a certain payload.

Wait, so its weight without fuel is higher, it carries more fuel (which adds weight), and its take off weight it the same??

Something has to give. That must mean that payload takes a hit.
Yet it can carry more cargo and pax. What am I missing here?

Hopefully the fuel consumption is less.

When the future operator needs less fuel to fly a higher payload over the same distance (+200nm) the MTOW can remain the same as with the 77W.

danj555 wrote:

Wait, so its weight without fuel is higher, it carries more fuel (which adds weight), and its take off weight it the same??

Something has to give. That must mean that payload takes a hit.
Yet it can carry more cargo and pax. What am I missing here?

No, the fuel capacilty is higher becase of a larger wing where fuel is stored, which will rarely be filled. Typical fuel loads on a flight will be lower than the existing 777's.

Sometimes increases in weight reduce fuel consumption in aircraft...If the the weight is going into more effcient higher bypass ratio jet engines or a higher aspect ratio wing. Both are the case for the 777X.

danj555 wrote:

Yet it can carry more cargo and pax. What am I missing here?

Full payload does not allow full tanks.
Full tanks allow a certain, reduced payload.
Between full payload (MZFW) and full tanks you exchange payload for fuel.
Beyond you reduce payload at about twice that rate to achieve comparable incremental range.

extreme example on the left side is the A321 without aux tanks. full payload and full tanks is just 3 miles apart
extreme example on the right is the A332 that before the last MTOW boosts could not
completely fill its tanks even with zero payload.