An off-topic discussion of a potential 777X freighter derailed the 777X production thread, but it was a worthwhile discussion, and I thought I'd continue it here.

The freight market has had wild swings lately as the receding world economy and the drastic drop in passenger travel under COVID-19 push freight trends in opposite directions. It's hard to know right now how much demand there will be for additional new-build freight aircraft. But if there is such demand, what will they be?

We have the following contenders:

250 t: An-225. One built, second never completed, staggeringly expensive to fly, not likely for further production.
150 t: An-124. 55 built, marginal if any production capacity, expensive to operate, not likely to satisfy a big market.
139 t: 747-8F. Likely 105 built by the end of production, not possible to produce profitably.
103 t: 777F. Still in production with 231 total orders, and apparently profitable.

Unless there is a possibility for a MTOW increase that Boeing is not disclosing, I don't see how a 777X freighter would carry significantly more payload than the 777F. It will have similar MTOW and higher OEW; it will burn less fuel, but not enough less to change the payload equation.

What do you think is the future of this market?

The fundamental issue is when passenger flights are at normal levels there is excess cargo capacity in the market.

Market demand for new large freighters is at a low, years away from replacement cycle.

As a result of covid there will be an unprecedented level of viable widebody aircraft available for conversion.

The MTOW of the 77X is limited by the gear, any more and a center main gear would probably be needed, unlikely to happen.

The 77F will probably always have more payload than a 778F would have as the new engines are substantially heavier. However, once the route is further than the flat top of the payload range curve the 778F will carry more to that distance. The traditional routes thru ANC fall where the 77F carries more. But flying from Memphis there are a bunch of destinations where the 778F would be killer.

The 773 P2F conversion will be an excellent hauler where volume limited cargo is flown, but it must be density about 3/4 of the typical freight density. Heavy stuff can go in the hold, though.

Once Boeing certifies the 778F, it will be good for 20 to 30 orders per year, like the 77F has been.

There has never been a civilian freighter designed as such. The reason is simple; the only time anything HAS to be shipped by air is disaster/emergency relief. And then the military usually steps in (which DOES have purpose built freighters, none of which except the AN-124 and AN-225 have found their way into civilian use). Any other time it is a cost/benefit analysis as to whether to ship something by air or on the surface. If it is too big or too heavy the choice is already made.

The point is that there is simply insufficient demand for a purpose built freighter, especially for outsized cargo to justify designing and building them. The ANs manage to keep busy, but had they not already existed and been rendered surplus they would not be on the scene. Even with another partially built AN-225 there has not been the resources available to complete it. So when the present one is no longer airworthy the cargo it now carries will be carried on the surface.

There was one plane that although designed as a passenger airliner was also optimized as a freighter, and that was the 747. But that was because Joe Sutter figured that the airlines would soon switch over to SSTs and leave his creation an orphan, and so he did all he could to make sure it would serve well as a freighter. Airbus, unfortunately, did not put enough thought into the A380, which turned out to be a lousy base for a freighter.

So what it comes down to is that for the foreseeable future dedicated freighters will be either converted airliners or new build airliners built as freighters. As the 777 is soon going to be the largest plane in production, if you want a new built large freighter that will be your only option. If you want to ship something bigger than it will carry you’ll have to whistle up a 747 or AN. Once they are all gone then you will be out of luck. And with the turmoil the entire industry is going through now I think it will be a long, long time before anyone tries to build a larger plane.

Unless Russia is successful in building their proposed An-124 replacement, the "Slon" or "Elephant" which is supposed to have a payload of 180 t and use four of the PD35 engines intended for the CR929.

I see the 778F as a FedEx TPAC special, maybe with a few other sales to other operators flying TPAC nonstop with high utilization. That's not a big market. Other markets seem better suited for some combination of legacy 747s, 77W CF (which I should have included in the list), and 77F. The 778F will be extremely expensive to buy and will save significant fuel only on those nonstop TPAC routes.

I suspect the future of the 778F as a whole depends on the state of FedEx's finances in a few years.

Something that would be much cheaper to build, once engineered, would be a 789F. If I had to bet, I think I'd bet that a 789F will be on the Boeing price list before a 778F. A 789F ought to carry around 80 t over 3500 nm, not shabby at all. By the late 2020s, two of them might even be cheaper to operate than a single aging 747F.

seabosdca wrote:

I see the 778F as a FedEx TPAC special, maybe with a few other sales to other operators flying TPAC nonstop with high utilization.

I don’t agree, I think they will go with converted 77Ws as that gives them more volume (bit over 10’ longer) and a lot cheaper. Will be lots of cheap 77Ws as stock available.

FedEx is volume driven, not weight.

I am not remotely involved in aircraft construction and know only the basic fundamentals of aeronautics. The current model of developing a freighter version of a current pax airliner means that cargo flies in relative comfort and at high speed over long distances, in pressurised aircraft

It must be way more straightforward to build a rugged fuselage without pressurisation, with loading designed in from the start (front loading, rear ramp, large side door, or .....) perhaps high winged to reduce the height of the loading "door", no bleeding edge technology on engines, wings, or anything else, and designed to operate from normal airports with hard runways.Just how important is speed to cargo operators - probably most bulky cargo is not time sensitive, and stuff that is goes in the cargo holds of pax aircraft mainly? Such an aircraft would not be in the same price league as the current passenger heavies!

FedEx has ordered a fair first batch (75?) of a new Cessna twin engined aircraft designed to carry 3 standard containers. It can also be configured to carry 20 (?) pax, but was designed as a freighter. It is relatively cheap, it is "slow", and it can only do 800km hops! Now scale that up to A350/B777 dimensions with scaled up performance - a bit more speed and range. What is not to like there as a purpose built freight hauler?

I'm sure that aircraft like the A400 end up as an expensive pig as a result of attempting to include lots of exotic military requirements, operating from unprepared strips, etc

zeke wrote:

I don’t agree, I think they will go with converted 77Ws as that gives them more volume (bit over 10’ longer) and a lot cheaper. Will be lots of cheap 77Ws as stock available.

FedEx is volume driven, not weight.

FedEx gets enough utilization out of their TPAC fleet (15+ hours/day) that I expect the fuel savings of the 778 compared to converted 77Ws will be worth the price on those missions. But I also think they might well eventually buy converted 77Ws as an MD-11 replacement for shorter missions.

744SPX wrote:

Unless Russia is successful in building their proposed An-124 replacement, the "Slon" or "Elephant" which is supposed to have a payload of 180 t and use four of the PD35 engines intended for the CR929.

I won’t hold my breath. The same laws of supply and demand work in Russia as in the West. The only purpose built freighters in aviation history have been for the military, and I doubt that the Russian military is able to fund one at this time. And even if they do, it’s use will probably strictly military. The only reason the ANs came into civilian use is the military no longer wanted them. If they design a replacement, that will not happen. And they will undoubtedly be too expensive for civilian use.

seabosdca wrote:

FedEx gets enough utilization out of their TPAC fleet (15+ hours/day) that I expect the fuel savings of the 778 compared to converted 77Ws will be worth the price on those missions. But I also think they might well eventually buy converted 77Ws as an MD-11 replacement for shorter missions.

Have you got any evidence to show a 778 burns less fuel than a 77W ?
The 778 I would expect to be heavier than a 77W, and carries less volume.

FedEx is a business, if they can save 50-100 million in the capital cost per frame by converting surplus 77Ws, the 778 would never stack up in a business case. The only way you comment would make sense is if you are comparing new build 77W to new build 778, which is not what I was suggesting.

zeke wrote:

seabosdca wrote:

Have you got any evidence to show a 778 burns less fuel than a 77W ?

You mean other than the many claims, which neither GE nor Boeing has given us any reason to doubt, that the GE9x has 10% better cruise SFC than the latest GE90? The weight difference between the two frames should be much smaller than that.

If the 778 couldn't beat a 77W in fuel consumption on a long flight, the passenger 779 wouldn't have attracted a single order.

zeke wrote:

seabosdca wrote:

FedEx gets enough utilization out of their TPAC fleet (15+ hours/day) that I expect the fuel savings of the 778 compared to converted 77Ws will be worth the price on those missions. But I also think they might well eventually buy converted 77Ws as an MD-11 replacement for shorter missions.

Have you got any evidence to show a 778 burns less fuel than a 77W ?
The 778 I would expect to be heavier than a 77W, and carries less volume.

FedEx is a business, if they can save 50-100 million in the capital cost per frame by converting surplus 77Ws, the 778 would never stack up in a business case. The only way you comment would make sense is if you are comparing new build 77W to new build 778, which is not what I was suggesting.

Are you serious?what on earth? LOOOOOOL.

Don’t argue for argument sake...an aircraft that’s about 12ft shorter has longer carbon fibre wings (last we heard kept the same weight as the current wings) please bring your calculator and show us how you deduced the aircraft will be heavier.

If you don’t like the plane say you don’t like the plane because I’m sure you know what statement sounds like you’ve run out of reasonable arguments. You had a good argument with regards to the Freighter 77W vs the freighter 778 but fuel burn can simply not be one of them, unless you’re an engineer at Boeing and you have something to tell us, if not then please go back to your previous argument points.

sassiciai wrote:

I am not remotely involved in aircraft construction and know only the basic fundamentals of aeronautics. The current model of developing a freighter version of a current pax airliner means that cargo flies in relative comfort and at high speed over long distances, in pressurised aircraft

It must be way more straightforward to build a rugged fuselage without pressurisation, with loading designed in from the start (front loading, rear ramp, large side door, or .....) perhaps high winged to reduce the height of the loading "door", no bleeding edge technology on engines, wings, or anything else, and designed to operate from normal airports with hard runways.Just how important is speed to cargo operators - probably most bulky cargo is not time sensitive, and stuff that is goes in the cargo holds of pax aircraft mainly? Such an aircraft would not be in the same price league as the current passenger heavies!

FedEx has ordered a fair first batch (75?) of a new Cessna twin engined aircraft designed to carry 3 standard containers. It can also be configured to carry 20 (?) pax, but was designed as a freighter. It is relatively cheap, it is "slow", and it can only do 800km hops! Now scale that up to A350/B777 dimensions with scaled up performance - a bit more speed and range. What is not to like there as a purpose built freight hauler?

I'm sure that aircraft like the A400 end up as an expensive pig as a result of attempting to include lots of exotic military requirements, operating from unprepared strips, etc

The number of freighters needed to be sold to cover the development cost exceeds the market. It would have to have a military version to get those quantities needed to make it a success. The GEnX on a B764 freighter, it would have quite good numbers as low development cost.

BTW I love the SkyCourier, a freighter design first that will be a real workhorse. FedEx did a launch order of 50 + 50 options. FedEx already has several hundred Caravans so the SkyCourier covers well above that.

seabosdca wrote:

You mean other than the many claims, which neither GE nor Boeing has given us any reason to doubt, that the GE9x has 10% better cruise SFC than the latest GE90?

TSFC and block fuel are not the same. You made reference to block fuel.

Opus99 wrote:

Don’t argue for argument sake...an aircraft that’s about 12ft shorter has longer carbon fibre wings (last we heard kept the same weight as the current wings) please bring your calculator and show us how you deduced the aircraft will be heavier.

Show me where anyone has said officially the wing weight is the same ? AW&ST ran an article last year on the engine saying the weight of it including the pylon on the test aircraft was 40,000 lb.

The 778 as far as I am aware has more surface area (wings and engine) than the 77W. Happy to be corrected.

Carbon fibre does not mean lighter, the 767 is what 20-30 tonnes lighter than a 787 ?

zeke wrote:

seabosdca wrote:

You mean other than the many claims, which neither GE nor Boeing has given us any reason to doubt, that the GE9x has 10% better cruise SFC than the latest GE90?

TSFC and block fuel are not the same. You made reference to block fuel.

Opus99 wrote:

Don’t argue for argument sake...an aircraft that’s about 12ft shorter has longer carbon fibre wings (last we heard kept the same weight as the current wings) please bring your calculator and show us how you deduced the aircraft will be heavier.

Show me where anyone has said officially the wing weight is the same ? AW&ST ran an article last year on the engine saying the weight of it including the pylon on the test aircraft was 40,000 lb.

The 778 as far as I am aware has more surface area (wings and engine) than the 77W. Happy to be corrected.

Carbon fibre does not mean lighter, the 767 is what 20-30 tonnes lighter than a 787 ?

Please from the below. Leeham did a series of the the 777X at the start of last year:

https://leehamnews.com/2019/01/31/boein ... ed-part-2/

The quote:
“With a 7m longer wingspan (71.8m compared with 64.8m for the 777-200LR/300ER), there was no weight gain. But the fact an 11% longer wing could be kept at the same weight as the donor’s wing, it’s no small achievement.“

Do you have any proof the weight had increased. ALSO that engine weight would make GE huge liars as they’ve said the GE9X is roughly the same weight as the GE90 albeit slightly heavier. You’re saying the engine is DOUBLE the weight of the GE90. Come on. Even in this same article is says

“While the higher pressure ratio improves the engine’s efficiency, it also increases the weight of the engine. The engine’s core must be designed for higher loads as the pressures inside the engine have increased with almost 50% compared with the GE90.
In total, the installed weight of a GE9X with nacelle is more than two tonnes heavier than the GE90-115 installation on the 777-300ER.“

If it was double the weight then honestly a statement that says more than two tonnes is gravely misleading.

The GE90 is at about 19,300 pounds.

Unless of course the pylon brings on the same weight as the engine. So maybe combined they can be that. I don’t know.

Opus99 wrote:

Leeham did a series of the the 777X at the start of last year:

https://leehamnews.com/2019/01/31/boein ... ed-part-2/

The quote:
“With a 7m longer wingspan (71.8m compared with 64.8m for the 777-200LR/300ER), there was no weight gain. But the fact an 11% longer wing could be kept at the same weight as the donor’s wing, it’s no small achievement.“

I appreciate the quote, it is still an opinion, not fact.

Opus99 wrote:

Do you have any proof the weight had increased.

I have no proof, just the list of changes made, little things like changing the windows even adds weight. Carbon fibre does not automatically mean lighter, there are many areas where metal is actually preferable over car in fibre.

Opus99 wrote:

ALSO that engine weight would make GE huge liars as they’ve said the GE9X is roughly the same weight as the GE90 albeit slightly heavier.

which one is it, same or heavier, cannot be both.

Opus99 wrote:

You’re saying the engine is DOUBLE the weight of the GE90.

The article is said 40,000 lb for the engine and pylon.

Opus99 wrote:

Come on. Even in this same article is says

“In total, the installed weight of a GE9X with nacelle is more than two tonnes heavier than the GE90-115 installation on the 777-300ER.“

Which is 25-30% heavier, depends on what “more than two tonnes heavier” means, is that 2.5 tonnes, 5 tonnes, it provides no upper limit.

zeke wrote:

Opus99 wrote:

Leeham did a series of the the 777X at the start of last year:

https://leehamnews.com/2019/01/31/boein ... ed-part-2/

The quote:
“With a 7m longer wingspan (71.8m compared with 64.8m for the 777-200LR/300ER), there was no weight gain. But the fact an 11% longer wing could be kept at the same weight as the donor’s wing, it’s no small achievement.“

I appreciate the quote, it is still an opinion, not fact.

Opus99 wrote:

Do you have any proof the weight had increased.

I have no proof, just the list of changes made, little things like changing the windows even adds weight. Carbon fibre does not automatically mean lighter, there are many areas where metal is actually preferable over car in fibre.

Opus99 wrote:

ALSO that engine weight would make GE huge liars as they’ve said the GE9X is roughly the same weight as the GE90 albeit slightly heavier.

which one is it, same or heavier, cannot be both.

Opus99 wrote:

You’re saying the engine is DOUBLE the weight of the GE90.

The article is said 40,000 lb for the engine and pylon.

Opus99 wrote:

Come on. Even in this same article is says

“In total, the installed weight of a GE9X with nacelle is more than two tonnes heavier than the GE90-115 installation on the 777-300ER.“

Which is 25-30% heavier, depends on what “more than two tonnes heavier” means, is that 2.5 tonnes, 5 tonnes, it provides no upper limit.

Roughly the same. I said you can’t just take out the roughly. If sometimes us 5.2 tonnes and 5.3 tonnes, saying its roughly the same is correct in this context. Even though 5.3 tonnes is heavier.

Of course there’s no upper limit on the quote but you know that quote certainly doesn’t mean another 19 tonnes heavier. I mean! LOL

Honestly, time will tell. I do agree that the 778F will have a tough sell against the 77WSF. For multiple reasons but I don’t think the the 778 being less efficient than the 77W will be one of them

zeke wrote:

seabosdca wrote:

You mean other than the many claims, which neither GE nor Boeing has given us any reason to doubt, that the GE9x has 10% better cruise SFC than the latest GE90?

TSFC and block fuel are not the same. You made reference to block fuel.

No, they're not, but there is no reason the 778 should require enough additional thrust in cruise to make up the TFSC difference. I continue to think a 778F will have a trip fuel burn advantage over a 77W CF that will grow as flights get longer, which is why I think it would be a good product for the few operators who are flying freight transpacific without stops and with high utilization. I don't know that that market is big enough to support its development.

Unless FedEx and/or UPS ante-up and place large launch orders for the (still-conceptual) B778F, there is little chance a development program will go forward. That said, FedEx is in the midst of a fleet renewal that adds more of the existing B777F's for long & heavy-haul, so they should be pretty well set for the next decade. A similar situation exists for UPS, who is taking the last of a large order of the B748F, so their long & heavy haul needs are being filled. Besides FedEx and UPS, no other freight-only airlines have the size, financial strength and scope to launch the B778F.

Some mention designing a high-wing/ramp-loading aircraft similar to a C-17, but forget that MDD already failed badly trying to market the de-militarized version of the C-17 as a civilian freighter. If developed, such a plane would have a very tiny market and would trade loading ease/cargo capacity for higher empty airframe weight and substantially less operational efficiency when compared to airliner-based freighters.

The 777X-F may be able to carry more payload and replace 744F from range and weight perspective. It would be ideal for express carriers such as FedEx and UPS or those specializing in shipping fresh produce when they need a large freighter to carry parcels and vegetables and fish on trunk routes. But there is a hole for a freighter replacement for outsized cargo. Something with a front cargo door like the 748F will be needed fo such cargo. The market is small so I don't see Boeing or Airbus jumping into it and designing an aircraft for it. We may either see the 748F continuing to fly for the next 50 years (similar to how 732s are still flying Canadian Arctic) or they will need to use a civilian version of C-17 or A400M (which doesn't exist now) as replacement.

FLALEFTY wrote:

Some mention designing a high-wing/ramp-loading aircraft similar to a C-17, but forget that MDD already failed badly trying to market the de-militarized version of the C-17 as a civilian freighter. If developed, such a plane would have a very tiny market and would trade loading ease/cargo capacity for higher empty airframe weight and substantially less operational efficiency when compared to airliner-based freighters.

The "ramp" would not need to reach the ground. It would only need to reach level to allow loading of long items. I believe it would be cheaper to do that than a swing tail. It could also be done in a way that allows appropriate pressurization of the air-frame for carrying certain cargo.

I suspect that Boeing is looking at that option for the 77XF.

Have a great day,

What about a A350F (the -900 or -1000)? Does it make sense for Airbus to introduce a dedicated freighter?

raylee67 wrote:

The 777X-F may be able to carry more payload and replace 744F from range and weight perspective. It would be ideal for express carriers such as FedEx and UPS or those specializing in shipping fresh produce when they need a large freighter to carry parcels and vegetables and fish on trunk routes. But there is a hole for a freighter replacement for outsized cargo. Something with a front cargo door like the 748F will be needed fo such cargo. The market is small so I don't see Boeing or Airbus jumping into it and designing an aircraft for it. We may either see the 748F continuing to fly for the next 50 years (similar to how 732s are still flying Canadian Arctic) or they will need to use a civilian version of C-17 or A400M (which doesn't exist now) as replacement.

Issue with a civilian C-17 though is that it has been out of production for 5 years and the Long Beach was sold in 2019.

How solid is the 777-8 specs?

Could Boeing reduced the length to make it a better freighter?

777F is 63.73m
777-300ER is 73.86m
777-8 is 69.80m
777-9 is 76.73m

Could the 777-8 have its length reduced to 66.8 metres? That gives it the same 10 metre length difference that the older models have. It is this much shorter fuselage of the 777F with the high landing weight that allows such a high payload weight.

The 777 fuselage weight is just over 2000kg per metre. So a 3 metre shorter fuselage will allow for 6t of extra payload bringing it back up to the current 777F but just reduced fuel burn. So a 66.8m 777-8F would be the best choice. If there is no passenger version of the 777-8 they could even use the non sculpted sidewalls if they are lighter.

The 777-9 has a landing weight quite a bit higher than the 777-300ER at over 260t. So in theory the 777-8 freighter could have a higher landing weight compared to the 777F.

With a landing weight of 270t I would think the 777-8F could easily match the 777F in terms of max payload. MTOW is not the issue here.

raylee67 wrote:

or they will need to use a civilian version of C-17 or A400M (which doesn't exist now) as replacement.

Strictly speaking, a civilian A400 already exists. The A400 has a civilian certification. May even be close to securing an order for two for the Indonesian national oil company.

SEPilot wrote:

and I doubt that the Russian military is able to fund one at this time. And even if they do, it’s use will probably strictly military. The only reason the ANs came into civilian use is the military no longer wanted them. If they design a replacement, that will not happen. And they will undoubtedly be too expensive for civilian use.

Most images that have been released suggest the An-124 replacement will be a development of the An-124, stretched with bigger wings and engines. Hardly out of Russians means, they manager way more ambitious projects already. They are way more cost efficient than western manufacturers. But you are right about the expensive cost making them unlikely to see big use among civilian customers. Even the new build Il-76 only secured 4 civilian orders (and the 2 for the Jordanian AF's cargo airline).

RJMAZ wrote:

How solid is the 777-8 specs?

Could Boeing reduced the length to make it a better freighter?

777F is 63.73m
777-300ER is 73.86m
777-8 is 69.80m
777-9 is 76.73m

Could the 777-8 have its length reduced to 66.8 metres? That gives it the same 10 metre length difference that the older models have. It is this much shorter fuselage of the 777F with the high landing weight that allows such a high payload weight.

The 777 fuselage weight is just over 2000kg per metre. So a 3 metre shorter fuselage will allow for 6t of extra payload bringing it back up to the current 777F but just reduced fuel burn. So a 66.8m 777-8F would be the best choice. If there is no passenger version of the 777-8 they could even use the non sculpted sidewalls if they are lighter.

The 777-9 has a landing weight quite a bit higher than the 777-300ER at over 260t. So in theory the 777-8 freighter could have a higher landing weight compared to the 777F.

With a landing weight of 270t I would think the 777-8F could easily match the 777F in terms of max payload. MTOW is not the issue here.

I will be more provocative: if the passenger version of the 778 would be abandoned, why should the 778F be longer than the 772F if this would lead the 778F to have a lower payload than the 772F? It seems obvious now that the low density cargo will be flown in converted 773ER for the decades to come hence the gap to be filled is the one of high density cargo.

What I would like to understand better is the effect of the new wing on the MTOW and MLW. This new wing has more area and less sweep than the previous one. I understand that it will lead to reduced takeoff and landing speeds at any given takeoff weight and landing weight compared to the original wing. These reduced speeds will in turn require less breaking power in the case of a rejected takeoff or during any regular landing. The reduced landing speed might also induce less load in the landing gear upon touch down (although I believe that this load may be primarily driven by the vertical speed and aircraft landing weight rather than its ground speed). All in all, a bigger wing leading to reduced takeoff and landing speed could allow a given landing gear set to be operated at higher weights. In this case, the 778F would have the potential to be longer than the 772F without sacrificing the payload density.

Actually the 778F should rather have a higher payload capacity than the 772F because on the other side, Airbus could easily design an A359F as a shrink of the A351 with an equivalent payload as the 772F but burning at least 25% less fuel than the latter.

RJMAZ wrote:

How solid is the 777-8 specs?

Could Boeing reduced the length to make it a better freighter?

That might make it better for operators who are weight limited, but the operators I think are most likely to order the 778F if it is ever made are not weight limited. They need an airplane that can fly as much volume as possible with true TPAC range. I'd actually ask the opposite question: would it work better for them if stretched slightly to 773 length?

I think the only real option will be the 777X. It can never do what the 747 can, but that ship has sailed.
Freighter airlines have to make do with either second hand 747's or new 777's.
Airbus has nothing to compete and I don't see any other manufacturer step up and built a dedicated freighter.

RJMAZ wrote:

The 777 fuselage weight is just over 2000kg per metre. So a 3 metre shorter fuselage will allow for 6t of extra payload...

Is it made of cast iron?

I don't know how many pressurizations the B747-8 can handle, but I believe the last 20% or so will be kept for oversized cargo. Also in 15 years there will be better freighters for normal sized cargo, e.g. B777-8 including one engine update.

I can imagine that some will be still operational in 70 years, operating out of a desert only on charter by 2040.

How old are Antonovs/ B52s?

It has more volume, but The 778F will also have to carry more payload than the 777F to be viable. With the bigger wing it should be able to. I'm thinking ~112 metric tons. With those numbers it would also be significantly better than the 77WSF.

seabosdca wrote:

...if there is such demand, what will they be?

We have the following contenders:
250 t: An-225. One built, second never completed, staggeringly expensive to fly, not likely for further production.
150 t: An-124. 55 built, marginal if any production capacity, expensive to operate, not likely to satisfy a big market.
139 t: 747-8F. Likely 105 built by the end of production, not possible to produce profitably.
103 t: 777F. Still in production with 231 total orders, and apparently profitable.

Unless there is a possibility for a MTOW increase that Boeing is not disclosing, I don't see how a 777X freighter would carry significantly more payload than the 777F. It will have similar MTOW and higher OEW; it will burn less fuel, but not enough less to change the payload equation.

What do you think is the future of this market?

respecting the intent and scope defined by the topic author, a significant perspective would be a market expectation list
column headings: carrier; most likely choice btwn (778F, A359F, B77WCF, noOrder); range of order size (by the end of the decade?).

~product offerings ~2029
xxx t: 778F. The more time Aeronautical Engineers(AE) have to solve a puzzle, the better/aligned the product is for the market (respecting their overbuild biases)
xxx t: A359F
xxx t: B77WF conversion

~existing frames ~2029
150 t: An-124. economics and age taking its toll
139 t: 747-8F. market supporting subfleet
xxx t: 747-4F. factory built freighters will likely be active and economically productive
xxx t: 744 conversions. economic inferiority retiring the sub-fleet
103 t: 777F. market supporting subfleet
090 t: MD11F. fleet replacement strategies will be public

assumption: "Heavy Freight" replacement market, for practical purposes, ranges between the MD11F-B744F + the An-124
datum: bridge production of the 772F created a buyers market, tilting purchase decisions, resulting in a larger global HFA over a natural mean
hypothesis: growth acquisitions will/would be muted by the return of passenger service and its ancillary freight service

marcelh wrote:

What about a A350F (the -900 or -1000)? Does it make sense for Airbus to introduce a dedicated freighter?

Airbus announced an A350F freighter aspiration, telegraphing an A350 intent over an anticipated/discussed A330neoF.
Lightsaber summarized the groups thoughts that it would likely be a A359 with the 1000's gear.
viewtopic.php?f=3&t=1442001
imo: thought/discussion is merited for a minimum build(mb) A359F for volume operators with an expectation of an A350-1000neoF
The mb-A359F competing with the B77WCF and an A350neoF competing later in the life cycle with Boeing's 777F powered by/GE9X-105

seabosdca wrote:

What do you think is the future of this market?

in Seattle: How can the B778F evolve to be relevant in 2025-2045 now that it is no longer tied to B778P constraints?

in Kiev: One might consider Antonov taking on the audacious goal of converting A380s for freighter use. It would be folly to under-estimate the intellect or work ethic of the eastern Europeans. When asked about "thinking outside the box", former soviet bloc citizen replied in a heavy accent "I will solve problem, what is 'box'?"

amdiesen wrote:

in Seattle: How can the B778F evolve to be relevant in 2025-2045 now that it is no longer tied to B778P constraints?

I believe that Boeing has looked at or considered having a drop ramp tail - which just goes to essentially horizontal (not all the way to the ground) - in order to allow for the loading of oversized cargo in the proposed B777-8F.

I have no idea if it will be built. But, its something to look at and study as to how to continue to serve the oversized cargo market. Perhaps its only offered as an option for those that want it (likely only 10-20% of that sized freighter market); and they have to pay the premium to get it.

Time will tell... this game is still quite young.

Have a great day,

Sokes wrote:

RJMAZ wrote:

The 777 fuselage weight is just over 2000kg per metre. So a 3 metre shorter fuselage will allow for 6t of extra payload...

Is it made of cast iron?

The 777LR and 777-300ER have the same 347-351t MTOW. Empty weight difference is 22,700kg and the fuselage is 10.1m longer. That is 2,247kg per metre of fuselage.

The 777-200ER and 777-300 have the same 297-299t MTOW. Empty weight difference is 22,430kg. That is 2,220kg per metre of fuselage.

As I said correctly, the fuselage weight is just over 2000kg per metre.

RJMAZ wrote:

Sokes wrote:

RJMAZ wrote:

The 777 fuselage weight is just over 2000kg per metre. So a 3 metre shorter fuselage will allow for 6t of extra payload...

Is it made of cast iron?

The 777LR and 777-300ER have the same 347-351t MTOW. Empty weight difference is 22,700kg and the fuselage is 10.1m longer. That is 2,247kg per metre of fuselage.

The 777-200ER and 777-300 have the same 297-299t MTOW. Empty weight difference is 22,430kg. That is 2,220kg per metre of fuselage.

As I said correctly, the fuselage weight is just over 2000kg per metre.

Assuming 5 mm cast iron:
62 dm x 10 dm x 3.14 x 0.05 dm = roughly 100 liter. I'm not sure about cast iron density, something around 8 kg/ liter? Plenty of weight left for the floor.

Other way round:
If one multiplies 64,6m of the -300 with 2,2t/ m one gets 142,6t. I know the fuselage is not the same over full length. OEW is 168t. In my crude estimate the fuselage would be 85% of total weight.

But then your explanation makes sense. I don't know what doesn't add up. Somewhere there has to be a mistake in the data.

wing heavier than fuselage

seabosdca wrote:

RJMAZ wrote:

How solid is the 777-8 specs?

Could Boeing reduced the length to make it a better freighter?

That might make it better for operators who are weight limited, but the operators I think are most likely to order the 778F if it is ever made are not weight limited. They need an airplane that can fly as much volume as possible with true TPAC range. I'd actually ask the opposite question: would it work better for them if stretched slightly to 773 length?

I expect that the long range/low density market will be covered by converted 773ERs hence my post just before yours in which I concur with the idea that the 778F, if ever built, should rather address the high density market.

Sokes wrote:

RJMAZ wrote:

Sokes wrote:

Is it made of cast iron?

The 777LR and 777-300ER have the same 347-351t MTOW. Empty weight difference is 22,700kg and the fuselage is 10.1m longer. That is 2,247kg per metre of fuselage.

The 777-200ER and 777-300 have the same 297-299t MTOW. Empty weight difference is 22,430kg. That is 2,220kg per metre of fuselage.

As I said correctly, the fuselage weight is just over 2000kg per metre.

Assuming 5 mm cast iron:
62 dm x 10 dm x 3.14 x 0.05 dm = roughly 100 liter. I'm not sure about cast iron density, something around 8 kg/ liter? Plenty of weight left for the floor.

Other way round:
If one multiplies 64,6m of the -300 with 2,2t/ m one gets 142,6t. I know the fuselage is not the same over full length. OEW is 168t. In my crude estimate the fuselage would be 85% of total weight.

But then your explanation makes sense. I don't know what doesn't add up. Somewhere there has to be a mistake in the data.

Yes something doesn't make sense.

A raw 320 fuselage/barrel (the whole thing) is only around 5,000 KG - or about 5% of the MTOW.

If the 777 is 2,200 KG per meter of raw barrel then that means that an 779 barrel would be about 168,000 KG. Leaving about zero for things like engines, wings/wingbox, tail surfaces, gear, avionics, nose, interior fittings....You know the things that turn a cylinder into an actual airplane.

In any case if the 777xF is the same length as the 777F it should be able to lift more an equivalent distance, as it will burn less fuel.

Yes the engines might have gained a bit - but by many reports Wings are about the same, tail should be lighter, hybrid 787 Systems should be lighter, No heavy passenger windows on the freight version.

The list of things they have changed on the 777X is a lot longer than what they kept.

In any case I guess they built in room for a MTOW bump to 360T as rumoured, which could give an 778F more Volume and at least the same lift capability as 777f - probably a little more as if the new aero and wings are good to burn 10-12% less fuel that is a savings of 10-11T right there.

If the landing weight is 260T that could mean the ability to lift at least 110T and carry 90-100T of gas.

morrisond wrote:

Yes the engines might have gained a bit - but by many reports Wings are about the same
...
In any case I guess they built in room for a MTOW bump to 360T as rumoured...

You have a link about the wings?

I also believe there will be a MTOW bump.
Middle East is anyway too hot to start very heavy and why not to see first how the engines hold up?
Again: any links?

morrisond wrote:

If the 777 is 2,200 KG per meter of raw barrel then that means that an 779 barrel would be about 168,000 KG. Leaving about zero for things like engines, wings/wingbox, tail surfaces, gear, avionics, nose, interior fittings....

With a tall building the structure at the bottom is much heavier per meter than at the top. The fuselage section just behind the nose would extremely light per meter, for the 777 it would definitely be below 1000kg per meter. Any fuselage extension to make an aircraft longer will be at the wingbox end and will be much heavier per meter. Also the fuselage extension aft of the wing is heavier and stronger than the extension forward of the wing. This is because tail loads have to be carried through the rear fuselage.

Some of that extra weight in the 300 model would be used in the mid section as they have a higher landing weight. So the 2200kg per meter would probably be around 2000kg. This is why the 777F isn't much lighter than the 777LR. The freighter has a higher landing weight and also stronger floor beams.

The 777-8 freighter would hopefully get a higher landing weight than a passenger 777-8. Extra strengthening in the freighter makes it quite unique. If Boeing does cancel the passenger 777-8 then it would probably help the 777-8 become more optimised. A shorter fuselage would help significantly at increasing max payload it wouldn't have to be 777-200 length but every meter helps.

RJMAZ wrote:

morrisond wrote:

If the 777 is 2,200 KG per meter of raw barrel then that means that an 779 barrel would be about 168,000 KG. Leaving about zero for things like engines, wings/wingbox, tail surfaces, gear, avionics, nose, interior fittings....

With a tall building the structure at the bottom is much heavier per meter than at the top. The fuselage section just behind the nose would extremely light per meter, for the 777 it would definitely be below 1000kg per meter. Any fuselage extension to make an aircraft longer will be at the wingbox end and will be much heavier per meter. Also the fuselage extension aft of the wing is heavier and stronger than the extension forward of the wing. This is because tail loads have to be carried through the rear fuselage.

Some of that extra weight in the 300 model would be used in the mid section as they have a higher landing weight. So the 2200kg per meter would probably be around 2000kg. This is why the 777F isn't much lighter than the 777LR. The freighter has a higher landing weight and also stronger floor beams.

The 777-8 freighter would hopefully get a higher landing weight than a passenger 777-8. Extra strengthening in the freighter makes it quite unique. If Boeing does cancel the passenger 777-8 then it would probably help the 777-8 become more optimised. A shorter fuselage would help significantly at increasing max payload it wouldn't have to be 777-200 length but every meter helps.

Okay then an average of 1,500KG and then times say 60m ignoring Nose and tail still equals 90,000KG.

How do you go from 5,000KG on an A320 to 90,000 KG on an 777? That seems a little extreme - and aren't larger circles more weight efficient?

RJMAZ wrote:

With a tall building the structure at the bottom is much heavier per meter than at the top.

I admit I failed to consider this. Good point.
But I still believe there has to be a mistake in the data.
The totally overstretched A340-600 compared to -500 is 7,5 m longer, but weighs only six tons more, 800 kg/ meter.

zeke wrote:

seabosdca wrote:

You mean other than the many claims, which neither GE nor Boeing has given us any reason to doubt, that the GE9x has 10% better cruise SFC than the latest GE90?

TSFC and block fuel are not the same. You made reference to block fuel.

Opus99 wrote:

Don’t argue for argument sake...an aircraft that’s about 12ft shorter has longer carbon fibre wings (last we heard kept the same weight as the current wings) please bring your calculator and show us how you deduced the aircraft will be heavier.

Show me where anyone has said officially the wing weight is the same ? AW&ST ran an article last year on the engine saying the weight of it including the pylon on the test aircraft was 40,000 lb.

The 778 as far as I am aware has more surface area (wings and engine) than the 77W. Happy to be corrected.

Carbon fibre does not mean lighter, the 767 is what 20-30 tonnes lighter than a 787 ?

As I recall Boeing claimed the carbon fiber wing panels on the 777x would save approximately 5000 lbs per wing versus the existing 777 wing. If someone has different and or better information please post.

RJMAZ wrote:

Sokes wrote:

RJMAZ wrote:

The 777 fuselage weight is just over 2000kg per metre. So a 3 metre shorter fuselage will allow for 6t of extra payload...

Is it made of cast iron?

The 777LR and 777-300ER have the same 347-351t MTOW. Empty weight difference is 22,700kg and the fuselage is 10.1m longer. That is 2,247kg per metre of fuselage.

The 777-200ER and 777-300 have the same 297-299t MTOW. Empty weight difference is 22,430kg. That is 2,220kg per metre of fuselage.

As I said correctly, the fuselage weight is just over 2000kg per metre.

it is not correct for "simple stretching", but very interesting observation itself. thanks

RJMAZ wrote:

Sokes wrote:

RJMAZ wrote:

The 777 fuselage weight is just over 2000kg per metre. So a 3 metre shorter fuselage will allow for 6t of extra payload...

Is it made of cast iron?

The 777LR and 777-300ER have the same 347-351t MTOW. Empty weight difference is 22,700kg and the fuselage is 10.1m longer. That is 2,247kg per metre of fuselage.

The 777-200ER and 777-300 have the same 297-299t MTOW. Empty weight difference is 22,430kg. That is 2,220kg per metre of fuselage.

As I said correctly, the fuselage weight is just over 2000kg per metre.

There is a (BIG) difference between:
a) airplane weight per meter of fuselage
b) fuselage weight per meter of fuselage.

When you mention "fuselage weight", usually it means just that: weight of the fuselage; ie. definition b).
It becomes confusing when one writes "fuselage weight", but the intended definition was a) "airplane weight per meter of fuselage".

Fuselage weight of 2000 kg per meter would suggest something like cast iron indeed . . .

PW100 wrote:

RJMAZ wrote:

Sokes wrote:

Is it made of cast iron?

The 777LR and 777-300ER have the same 347-351t MTOW. Empty weight difference is 22,700kg and the fuselage is 10.1m longer. That is 2,247kg per metre of fuselage.

The 777-200ER and 777-300 have the same 297-299t MTOW. Empty weight difference is 22,430kg. That is 2,220kg per metre of fuselage.

As I said correctly, the fuselage weight is just over 2000kg per metre.

There is a (BIG) difference between:
a) airplane weight per meter of fuselage
b) fuselage weight per meter of fuselage.

When you mention "fuselage weight", usually it means just that: weight of the fuselage; ie. definition b).
It becomes confusing when one writes "fuselage weight", but the intended definition was a) "airplane weight per meter of fuselage".

Fuselage weight of 2000 kg per meter would suggest something like cast iron indeed . . .

Here's what I believe is being missed in this fuselage weight discussion.

The 777 Wikipedia article has the 22.43 tonne OEW difference the 772LR and the 773ER being discussed here. It also shows a 64-80 passenger difference between the two airplanes.

Think about the OEW difference as the additional weight needed to support the additional passengers. With a 72 avereage passenger delta, the additional weight per passenger is 311 kg. Included in this 311 kg would be:

Fuselage structure
Cabin furnishings (seats, bins, flight entertainment, A/C ducting, emergency oxygen etc)
Additional lower lobe cargo handling system
Additional lower lobe cargo fire suppression bottles
Additional cabin crew to support the added passengers
Additional Lavs
Additional catering
More potable water

These additions do add up. I've probably missed a few.

Obviously, most of this wouldn't apply to adding body length to a freighter where the main weight additions would be:

Fuselage structure
Additional cargo handling system ( main deck and lower lobe)
More lower lobe cargo fire suppression bottles

Moral: Passenger and Freighter OEW's are not comparable.

ElroyJetson wrote:

zeke wrote:

seabosdca wrote:

You mean other than the many claims, which neither GE nor Boeing has given us any reason to doubt, that the GE9x has 10% better cruise SFC than the latest GE90?

TSFC and block fuel are not the same. You made reference to block fuel.

Opus99 wrote:

Don’t argue for argument sake...an aircraft that’s about 12ft shorter has longer carbon fibre wings (last we heard kept the same weight as the current wings) please bring your calculator and show us how you deduced the aircraft will be heavier.

Show me where anyone has said officially the wing weight is the same ? AW&ST ran an article last year on the engine saying the weight of it including the pylon on the test aircraft was 40,000 lb.

The 778 as far as I am aware has more surface area (wings and engine) than the 77W. Happy to be corrected.

Carbon fibre does not mean lighter, the 767 is what 20-30 tonnes lighter than a 787 ?

As I recall Boeing claimed the carbon fiber wing panels on the 777x would save approximately 5000 lbs per wing versus the existing 777 wing. If someone has different and or better information please post.

The wing area of the composite wing on the 777X is around 18 percent larger than the wing area of the 77F/77L/77W wing, and around 20 percent larger than the wing area of the 772/77E/773 wing.

https://modernairliners.com/boeing-777/boeing-777x/
https://en.wikipedia.org/wiki/Boeing_777X#Specifications
https://en.wikipedia.org/wiki/Boeing_777#Specifications
https://www.popularmechanics.com/flight/a17117/boeing-777x-wing-design/

OldAeroGuy wrote:

PW100 wrote:

RJMAZ wrote:

The 777LR and 777-300ER have the same 347-351t MTOW. Empty weight difference is 22,700kg and the fuselage is 10.1m longer. That is 2,247kg per metre of fuselage.

The 777-200ER and 777-300 have the same 297-299t MTOW. Empty weight difference is 22,430kg. That is 2,220kg per metre of fuselage.

As I said correctly, the fuselage weight is just over 2000kg per metre.

There is a (BIG) difference between:
a) airplane weight per meter of fuselage
b) fuselage weight per meter of fuselage.

When you mention "fuselage weight", usually it means just that: weight of the fuselage; ie. definition b).
It becomes confusing when one writes "fuselage weight", but the intended definition was a) "airplane weight per meter of fuselage".

Fuselage weight of 2000 kg per meter would suggest something like cast iron indeed . . .

Here's what I believe is being missed in this fuselage weight discussion.

The 777 Wikipedia article has the 22.43 tonne OEW difference the 772LR and the 773ER being discussed here. It also shows a 64-80 passenger difference between the two airplanes.

Think about the OEW difference as the additional weight needed to support the additional passengers. With a 72 avereage passenger delta, the additional weight per passenger is 311 kg. Included in this 311 kg would be:

Fuselage structure
Cabin furnishings (seats, bins, flight entertainment, A/C ducting, emergency oxygen etc)
Additional lower lobe cargo handling system
Additional lower lobe cargo fire suppression bottles
Additional cabin crew to support the added passengers
Additional Lavs
Additional catering
More potable water

These additions do add up. I've probably missed a few.

Obviously, most of this wouldn't apply to adding body length to a freighter where the main weight additions would be:

Fuselage structure
Additional cargo handling system ( main deck and lower lobe)
More lower lobe cargo fire suppression bottles

Moral: Passenger and Freighter OEW's are not comparable.

anyway 777 OEW difference is unusual
345/6 example from other side


upd: 781-789 = 6 650kg
length + 5.47m

There already is an outsize freighter in existence, based on an in-production design, that features front loading, that no-one has yet mentioned - the A330 Beluga. If the demand was there I'm sure Airbus would be happy to modify this design (slightly less extreme fuselage barrel for example?) to create a production version.