Pardon me if anyone has posted this before. I didn't find anything by search...

Given how efficient and successful 787 series are, It seems to me that it make sense to develop a higher MTOW 787-10 to compete with 359. Why letting 359 be the only replacement, as of now, of 77E?

A higher MTOW would add to empty weight and thus make the airplane burn more fuel on short to medium range flights.

787 MLG are currently maxed out at current MTOW. I think there is still room with the wing.

Polot wrote:

787 MLG are currently maxed out at current MTOW. I think there is still room with the wing.

I agree with both assessments.

I believe the tires are also maxed out too. It is non-trivial to upgrade at this point. I'm thinking it might not be worth the effort.

Lightsaber

lightsaber wrote:

Polot wrote:

787 MLG are currently maxed out at current MTOW. I think there is still room with the wing.

I agree with both assessments.

I believe the tires are also maxed out too. It is non-trivial to upgrade at this point. I'm thinking it might not be worth the effort.

Lightsaber

If you do it you do it with a new engine and optimized wing so you can do a 9ER a 10 and 11 in my view and retain at least a two or three airplane family.

It’s not something to do now but in like 7 or so years I think.

Newbiepilot wrote:

A higher MTOW would add to empty weight and thus make the airplane burn more fuel on short to medium range flights.

but a 787-10ER would not be used for short flights

bigjku wrote:

lightsaber wrote:

Polot wrote:

787 MLG are currently maxed out at current MTOW. I think there is still room with the wing.

I agree with both assessments.

I believe the tires are also maxed out too. It is non-trivial to upgrade at this point. I'm thinking it might not be worth the effort.

Lightsaber

If you do it you do it with a new engine and optimized wing so you can do a 9ER a 10 and 11 in my view and retain at least a two or three airplane family.

It’s not something to do now but in like 7 or so years I think.

I see a better ROI in development of the 797. The 787-10 is exceptionally well optimized for missions of 3000nm to 4000nm per the great cicle mapper; even shorter mission if cargo volume is high. It is a mid-haul combi.

In aviation, there is no designing a plane to be everything. On longer missions the A359 wing and engines are better optimized for the fusalage length. But in the 3000 to 4000nm range, no other plane will beat the economics.

To make the plane competitive for longer missions requires a wing upgrade, ideally more wingspan with folding wingtips. It also requires new landing gear and ideally a new engine. e.g., something based off the GE9x which is quite an advancement for long haul engine efficiency.

The plane will see PIPs, e.g., CMC turbine blades. I just don't see it being competitive Asia to USA or Asia to Europe. But on every A333 route, it has far better economics.

The A359 will fly further very economically.

I guess the best analogy is the A333 versus the 77W. While the A333 wasn't is capable, it printed money for decades. The same is true of the 787-10.

What the 787-10 required was a better payload/range curve than the A333. Mission accomplished.

Yes, the A359 will have better economics on mission with great circle distances over 4500nm. Below 4000nm on the the 787-10 has a major advantage. In between, we will debate here for decades.

If you've read my posts on the A321NEO and 797, you know I believe in frequency and fragmentation. But there is also a market between certain city pairs for cargo. As a combi, the 787-10 is only behind the A350-1000 and 779. Each has a clear niche, so each shall sell well.

That means somewhat fewer 787-10 sales, but at this time I do not see a business case for what you propose.

Lightsaber

lightsaber wrote:

Polot wrote:

787 MLG are currently maxed out at current MTOW. I think there is still room with the wing.

I agree with both assessments.

I believe the tires are also maxed out too. It is non-trivial to upgrade at this point. I'm thinking it might not be worth the effort.

Lightsaber

Actually the landing gear is relatively fine.

Here are the exact details.

787-8 uses 50" diameter 20" wide tyres on 22" wheels. The wheels are spaced 51" apart.

The 787-9/10 has 54" diameter 21" wide tyres on 23" wheels. The wheels are spaced 60" apart.

The A350-900 has the same sized tyres as the 787-9/10 but they are spaced 68" apart. This extra spacing reduces pavement loading.

The A350-1000 uses the smaller 787-8 tyres but has 6 wheels.

So the tyres can easily take the weight but it is the spacing of the wheels that are a problem. So the issue is entirely pavement loading which can limit what airports the aircraft can operate from.

The ACN pavement loading for the 787 is already extremely high but not as high as a 777-300ER. So maximum takeoff weight could be increased from a pavement loading perspective while retaining a landing gear that still physically fits.

An increased maximum takeoff weight would place greater loads on the wing, wingbox and landing gear. So everything will need to be strengthened which is par for the course.

I couldn't see a maximum takeoff weight increasing above 260T. It is worth noting Airbus regularly does small maximum takeoff weight increases but Boeing does not. So I doubt it will happen.

It would in theory be easier to bring the 787-9 up to 260T maximum takeoff weight. The 787-10 has a stronger wing than the -9 and the landing weight is higher. Boeing has already started to fit the stronger -10 parts onto the -9. So the 787-9 would have the most headroom for an increase to create a 787-9ER. Such an aircraft would be niche and it would probably be easier to make a 787-8ER.

The 787-10ER would need additiinal strengthening. The cost wouldn't be worth it.

The biggest advantage of the current 787-10 is it's extremely low empty weight for its cabin area. This gives it excellent efficiency at medium haul. Any maximum takeoff weight increase would add empty weight and reduce its biggest advantage.

Maximum takeoff weights increases are short term thinking. In the medium term, engine improvements give you extra range. In 10 years time we'll be discussing the 787NEO. The engines will burn less fuel and the 787-10 will become a 7000+nm range aircraft and the 787-9 will become a 8000+mm aircraft.

RJMAZ wrote:

the 787-10 will become a 7000+nm range aircraft and the 787-9 will become a 8000+mm aircraft.

I guess you meant 8000nm+ aircraft, not an 8-meter aircraft

Joking aside, isn't 787-9 already a 8000nm ULR aircraft, given it is used on LAX-SIN?

I guess pushing 787-10 higher MTOW will further affect 777-8 which is not selling well already ...

A 787 empty weight "reduction" along with keeping the MTOW the same would be a better fit for the 787. That, and engine improvements would make the 787-10 even more compelling...longer range, more cargo.

I'm sure after seven years in service, where and how weight could be shaved is now known. The 787 composite barrels and wings were a first cut...If reworked with upgraded technology and removal of unnecessary over-building due to a conservative design from over a decade ago...I imagine the 787 could drop a few tons.

moyangmm wrote:

RJMAZ wrote:

the 787-10 will become a 7000+nm range aircraft and the 787-9 will become a 8000+mm aircraft.

I guess you meant 8000nm+ aircraft, not an 8-meter aircraft

Joking aside, isn't 787-9 already a 8000nm ULR aircraft, given it is used on LAX-SIN?

That's wikipedia range. Most manufacturers list the range with a moderate density cabin with 100kg per passenger and no additional cargo.

If you run a low density cabin you can easily get an additional 10% range. Or if you run extra cargo the range can be reduced by 10% quite easily.

RJMAZ wrote:

lightsaber wrote:

Polot wrote:

787 MLG are currently maxed out at current MTOW. I think there is still room with the wing.

I agree with both assessments.

I believe the tires are also maxed out too. It is non-trivial to upgrade at this point. I'm thinking it might not be worth the effort.

Lightsaber

Actually the landing gear is relatively fine.

Here are the exact details.

787-8 uses 50" diameter 20" wide tyres on 22" wheels. The wheels are spaced 51" apart.

The 787-9/10 has 54" diameter 21" wide tyres on 23" wheels. The wheels are spaced 60" apart.

The A350-900 has the same sized tyres as the 787-9/10 but they are spaced 68" apart. This extra spacing reduces pavement loading.

The A350-1000 uses the smaller 787-8 tyres but has 6 wheels.

So the tyres can easily take the weight but it is the spacing of the wheels that are a problem. So the issue is entirely pavement loading which can limit what airports the aircraft can operate from.

The ACN pavement loading for the 787 is already extremely high but not as high as a 777-300ER. So maximum takeoff weight could be increased from a pavement loading perspective while retaining a landing gear that still physically fits.

An increased maximum takeoff weight would place greater loads on the wing, wingbox and landing gear. So everything will need to be strengthened which is par for the course.

I couldn't see a maximum takeoff weight increasing above 260T. It is worth noting Airbus regularly does small maximum takeoff weight increases but Boeing does not. So I doubt it will happen.

It would in theory be easier to bring the 787-9 up to 260T maximum takeoff weight. The 787-10 has a stronger wing than the -9 and the landing weight is higher. Boeing has already started to fit the stronger -10 parts onto the -9. So the 787-9 would have the most headroom for an increase to create a 787-9ER. Such an aircraft would be niche and it would probably be easier to make a 787-8ER.

The 787-10ER would need additiinal strengthening. The cost wouldn't be worth it.

The biggest advantage of the current 787-10 is it's extremely low empty weight for its cabin area. This gives it excellent efficiency at medium haul. Any maximum takeoff weight increase would add empty weight and reduce its biggest advantage.

Maximum takeoff weights increases are short term thinking. In the medium term, engine improvements give you extra range. In 10 years time we'll be discussing the 787NEO. The engines will burn less fuel and the 787-10 will become a 7000+nm range aircraft and the 787-9 will become a 8000+mm aircraft.

Te pavement loading is only part of the equation. When increasing MTOW you need to also account for an increase in tire speed (as your V1 speed will increase) as well as account for increased landing mass with a strengthened gear leg. Boeing uses the same gear for 789 and 10, and a gear designed for a theoretical higher mtow would weigh way too much for its current use. If a higher MTOW 787-10 was made, it, like the 764, would have its own new special landing gear.

QuarkFly wrote:

A 787 empty weight "reduction" along with keeping the MTOW the same would be a better fit for the 787. That, and engine improvements would make the 787-10 even more compelling...longer range, more cargo.

I'm sure after seven years in service, where and how weight could be shaved is now known. The 787 composite barrels and wings were a first cut...If reworked with upgraded technology and removal of unnecessary over-building due to a conservative design from over a decade ago...I imagine the 787 could drop a few tons.

Boeing has already been improving the production process with each model. So the 787-8 could probably see the biggest weight reduction with a rework, the 787-10 would gain the least.

I couldn't see more than 1000-2000kg removed from the empty weight of the 787-10. I could see 5000kg easily removed from the 787-8 if model specific parts are weight optimised using current production process. The 787-8 is instead getting weight optimised parts from the stronger heavier 787-9/10. This is purely for commonality so there isn't any real weight loss as the parts are overbuilt for the lighter 787-8.

The new main landing gear on the 764 isnt just to cater for the higher maximum take off weight


It is a significantly taller gear, along with using the same wheels and tires as the 777 the net result gains you 18’’ in height improving tail clearance at rotation and landing significantly


Although v speeds for TO and LDG were still increased to provide more margin still, resulting in its affection for longer runways

Obviously I'm not qualified enough to really explain why, but to make the 78X competitive to the A359 in terms of range/capability would require a fair few changes, which make it less efficient and lowers commonality. I imagine Boeing could make it pretty much par in terms of capability and efficiency, but in practice airlines that need the range are probably going to settle for the 789 or A359 anyway, the 789 is still close in size and is more optimised for the range. The 78X's differentiator is its superb efficiency on the routes it can operate, which make up the vast majority of routes flown today. Making it bigger reduces or else eliminates that advantage, and bear in mind all the aircraft in the space are optimised to fly further (if we include the future 251T A339), so it is a fairly unique selling point.

RJMAZ wrote:

The biggest advantage of the current 787-10 is it's extremely low empty weight for its cabin area.

Do we finally have a published OEW value for the 7810? How does it compare to the A359?
IMU the difference can't be that big. ( and the A359 has much more wing.)

WIederling wrote:

Do we finally have a published OEW value for the 7810?

135,500kg. That was the figure given in the updated 787 ACAP before the OEW and max payload data was removed.

I find this forum to be pretty fair. Both top OEMs have had triumphs and also humbling failures.

Airbus A320 family has led the industry for decades and still does. A330 is meaningfully superior to 767 in every way I know except trip cost. A350 is little discussed only because it has been such an uneventful, effective program. It will be a legendary airplane.

Still beggs the original question I posed, if as it has been claimed “Given how efficient and successful 787 series are” why do they need to do anything ?

I know the answer, as no Airbus aircraft can fill all market segments, except for the 787.

IBs MSN 219 is out of the paint hanger feTuring the new winglets, new aero improvements, weight changes, and engine pips giving it a fuel burn reduction of 5%, but still not good enough to compete with a 787 apparently.

moyangmm wrote:

Pardon me if anyone has posted this before. I didn't find anything by search...

Given how efficient and successful 787 series are, It seems to me that it make sense to develop a higher MTOW 787-10 to compete with 359. Why letting 359 be the only replacement, as of now, of 77E?

I Think most major 77E operators are taking A359’s for long flights from Asia. E.g. DL, SQ, AF, BA, CX, JAL, KL, UA, the Chinese.

The 787-10 with the usual cargo is more optimized for medium haul. Just like the A330-900. The MTOW boost of the latter to 251t will probably be used by most airlines, like Delta, to carry more cargo on 4000-5000NM flights.

AtomicGarden wrote:

Newbiepilot wrote:

A higher MTOW would add to empty weight and thus make the airplane burn more fuel on short to medium range flights.

but a 787-10ER would not be used for short flights

Not always the cause for some airlines fleet flexibility would make sense to have an single fleet of 787-10 e.g. not an seperate ER fleet but as ER's.

Its not unusual for the 777ER's and 789s to be used by the same airline on Long-Haul and Short-Haul sectors e.g. NZ uses the 789 on AKL-ORD* (From Nov) at around 15-16hours and as short as AKL-CHC at 1h20m.

zkncj wrote:

Its not unusual for the 777ER's and 789s to be used by the same airline on Long-Haul and Short-Haul sectors e.g. NZ uses the 789 on AKL-ORD* (From Nov) at around 15-16hours and as short as AKL-CHC at 1h20m.

Exactly it’s opportunity cost of operating the flight between long haul sectors vs having the aircraft sitting on the ground between long haul flights, the former results in lower fixed costs over the latter per flight hour.

I would not be surprised if this would happen, be it in a bit different matter:
787-9ER will be presented together with a 787-9ERF
787-9ER upgrades will be offered on the 787-10, making a 787-10ER

This obviously won't happen in the coming years, more like the mid 2020's or so., but I believe it will

keesje wrote:

I Think most major 77E operators are taking A359’s for long flights from Asia. E.g. DL, SQ, AF, BA, CX, JAL, KL, UA, the Chinese.

BA hasn't ordered the A359, but can add VN, MH, TG, and OZ to that list.

RJMAZ wrote:

lightsaber wrote:

Polot wrote:

787 MLG are currently maxed out at current MTOW. I think there is still room with the wing.

I agree with both assessments.

I believe the tires are also maxed out too. It is non-trivial to upgrade at this point. I'm thinking it might not be worth the effort.

Lightsaber

Actually the landing gear is relatively fine.

Here are the exact details.

787-8 uses 50" diameter 20" wide tyres on 22" wheels. The wheels are spaced 51" apart.

The 787-9/10 has 54" diameter 21" wide tyres on 23" wheels. The wheels are spaced 60" apart.

The A350-900 has the same sized tyres as the 787-9/10 but they are spaced 68" apart. This extra spacing reduces pavement loading.

The A350-1000 uses the smaller 787-8 tyres but has 6 wheels.

So the tyres can easily take the weight but it is the spacing of the wheels that are a problem. So the issue is entirely pavement loading which can limit what airports the aircraft can operate from.

The ACN pavement loading for the 787 is already extremely high but not as high as a 777-300ER. So maximum takeoff weight could be increased from a pavement loading perspective while retaining a landing gear that still physically fits.

An increased maximum takeoff weight would place greater loads on the wing, wingbox and landing gear. So everything will need to be strengthened which is par for the course.

I couldn't see a maximum takeoff weight increasing above 260T. It is worth noting Airbus regularly does small maximum takeoff weight increases but Boeing does not. So I doubt it will happen.

It would in theory be easier to bring the 787-9 up to 260T maximum takeoff weight. The 787-10 has a stronger wing than the -9 and the landing weight is higher. Boeing has already started to fit the stronger -10 parts onto the -9. So the 787-9 would have the most headroom for an increase to create a 787-9ER. Such an aircraft would be niche and it would probably be easier to make a 787-8ER.

The 787-10ER would need additiinal strengthening. The cost wouldn't be worth it.

The biggest advantage of the current 787-10 is it's extremely low empty weight for its cabin area. This gives it excellent efficiency at medium haul. Any maximum takeoff weight increase would add empty weight and reduce its biggest advantage.

Maximum takeoff weights increases are short term thinking. In the medium term, engine improvements give you extra range. In 10 years time we'll be discussing the 787NEO. The engines will burn less fuel and the 787-10 will become a 7000+nm range aircraft and the 787-9 will become a 8000+mm aircraft.

Both the 787-9 and 787-10 have the same MLG including the same tiers. The MLG is comparable to the MLG on the A330. 4 wheel boogies of similar size and the same tires.
The MTOW of the 787-9/10 is 254t. The A330 has 242t moving to 251t.
I would assume that for an increase in MTOW the 787-9/10 would need a bigger MLG (is there space for a bigger MLG aka A350-900?), a reinforced wing box, or perhaps a new designed wing box to fit a bigger MLG and reinforced wings.
One should not forget, that designs are not any longer done with unnecessary over designed parts. Better analysis aloud older designs like the 777 or A330 increased capabilities during the lifetime of the design.
We should not expect similar reserves in new designs. We should rather expect new designs being designed exactly for the intended capabilities, to not carry unnecessary weight.

Simple stretches like the 787-10 trade maximum range for improved efficiency at short ranges. It allows you to cover more of the market.

Increasing maximum takeoff weight in a family as the aircraft get larger will usually keep the range and efficiency of each model fairly close.

For example you could have two families.

Family A
200T 260 seat 7500nm range
220T 300 seat 7500nm range
240T 340 seat 7500nm range

Family B
300T 380 seat 7500nm range
330T 440 seat 7500nm range
360T 500 seat 7500nm range

All this provides is a slight capacity increase and poor commonality in the families. Engines would have big thrust ranges. The CASM efficiency across all of the models are similar.

Ideally you would want it to look like this.

Family C
220T 260 seat 8500nm range
220T 300 seat 7500nm range
220T 340 seat 6500nm range

Family D
330T 380 seat 8500nm range
330T 440 seat 7500nm range
330T 500 seat 6500nm range

Now the families have high commonality. You get more than capacity increments you now cover a broader spectrum of missions. You have two high efficiency medium haul 6500nm optimised aircraft and two ultra long haul 8500nm aircraft.

This is why the 787-9 and 787-10 combo is brilliant. It covers a broader spectrum of flights than the A330 and A350 families combined. Airbus does not have a high efficiency medium haul aircraft in its family. If the 777X wasn't in the picture Boeing would definitely produce a 787-8ER with the 254T MTO and create an aircraft able to fly 9000nm. This would create a very broad spectrum for the one family.

Airbus should have made the A350-1000 as a high efficiency but shorter ranged simple stretch with the 280T maximum takeoff. This would no doubt sell better in the long run.

zeke wrote:

Still beggs the original question I posed, if as it has been claimed “Given how efficient and successful 787 series are” why do they need to do anything ?

I know the answer, as no Airbus aircraft can fill all market segments, except for the 787.

IBs MSN 219 is out of the paint hanger feTuring the new winglets, new aero improvements, weight changes, and engine pips giving it a fuel burn reduction of 5%, but still not good enough to compete with a 787 apparently.

I don’t believe anyone specifically said the A359 can’t compete with the 787. Maybe that the A359 is a little less efficient on shorter-mid range routes vs the 78X. Airbus has shown with the A350 program an incredible achievement. The A350XWB program was one of the most well executed airliners programs I can think of. And they’ve created two incredible airplanes in the process with the A359/A35J. I think we are going to see the A35J find a lot of success when many of the 77W are up for replacement.

RJMAZ wrote:

Simple stretches like the 787-10 trade maximum range for improved efficiency at short ranges. It allows you to cover more of the market.

Increasing maximum takeoff weight in a family as the aircraft get larger will usually keep the range and efficiency of each model fairly close.

The 787-10 is a simple stretch of the 787-9. It did not only exchange just range, but also payload for a higher passenger capacity. If one looks at LCC or ULCC the 787-10 has the same max passenger numbers as the A330-900.

mjoelnir wrote:

The 787-10 is a simple stretch of the 787-9. It did not only exchange just range, but also payload for a higher passenger capacity. If one looks at LCC or ULCC the 787-10 has the same max passenger numbers as the A330-900.

Are you referring to the 787-10 and A330-900 having the same exit door limit of 440 seats? In practicality, very few airlines approach the max capacity of 440seats on the A330neo.

For Singapore Airlines, the 787-10 has 52 more seats than the A330-300. Except for a few extreme configurations like Cebu Pacific and Lion Air which represent only about a dozen airplanes, most LCCs cap A330 capacity to about 375 seats like Air Transat, Air AsiaX, Corsair, etc. For airlines like that and traditional airlines with 2 or 3 class service, I would expect the 787-10 to have around 25-65 more seats depending on configuration.

Newbiepilot wrote:

mjoelnir wrote:

The 787-10 is a simple stretch of the 787-9. It did not only exchange just range, but also payload for a higher passenger capacity. If one looks at LCC or ULCC the 787-10 has the same max passenger numbers as the A330-900.

Are you referring to the 787-10 and A330-900 having the same exit door limit of 440 seats? In practicality, very few airlines approach the max capacity of 440seats on the A330neo.

For Singapore Airlines, the 787-10 has 50 more seats. Except for a few extreme configurations like Cebu Pacific and Lion Air which represent only about a dozen airplanes, most LCCs cap A330 capacity to about 375 seats like Air Transat, Air AsiaX, Corsair, etc. For airlines like that and traditional airlines with 2 or 3 class service, I would expect the 787-10 to have around 50 more seats.

Some airlines do. I would hardly call Singapore Airlines an LCC or ULCC. CEBU pacific does 436, pretty near to the exit limit and Lion Air does exactly the limit 440 pax. I expect LCC or ULCC not doing long haul, but short to medium haul on wide bodies, to go near the exit limit.

mjoelnir wrote:

RJMAZ wrote:

lightsaber wrote:

I agree with both assessments.

I believe the tires are also maxed out too. It is non-trivial to upgrade at this point. I'm thinking it might not be worth the effort.

Lightsaber

Actually the landing gear is relatively fine.

Here are the exact details.

787-8 uses 50" diameter 20" wide tyres on 22" wheels. The wheels are spaced 51" apart.

The 787-9/10 has 54" diameter 21" wide tyres on 23" wheels. The wheels are spaced 60" apart.

The A350-900 has the same sized tyres as the 787-9/10 but they are spaced 68" apart. This extra spacing reduces pavement loading.

The A350-1000 uses the smaller 787-8 tyres but has 6 wheels.

So the tyres can easily take the weight but it is the spacing of the wheels that are a problem. So the issue is entirely pavement loading which can limit what airports the aircraft can operate from.

The ACN pavement loading for the 787 is already extremely high but not as high as a 777-300ER. So maximum takeoff weight could be increased from a pavement loading perspective while retaining a landing gear that still physically fits.

An increased maximum takeoff weight would place greater loads on the wing, wingbox and landing gear. So everything will need to be strengthened which is par for the course.

I couldn't see a maximum takeoff weight increasing above 260T. It is worth noting Airbus regularly does small maximum takeoff weight increases but Boeing does not. So I doubt it will happen.

It would in theory be easier to bring the 787-9 up to 260T maximum takeoff weight. The 787-10 has a stronger wing than the -9 and the landing weight is higher. Boeing has already started to fit the stronger -10 parts onto the -9. So the 787-9 would have the most headroom for an increase to create a 787-9ER. Such an aircraft would be niche and it would probably be easier to make a 787-8ER.

The 787-10ER would need additiinal strengthening. The cost wouldn't be worth it.

The biggest advantage of the current 787-10 is it's extremely low empty weight for its cabin area. This gives it excellent efficiency at medium haul. Any maximum takeoff weight increase would add empty weight and reduce its biggest advantage.

Maximum takeoff weights increases are short term thinking. In the medium term, engine improvements give you extra range. In 10 years time we'll be discussing the 787NEO. The engines will burn less fuel and the 787-10 will become a 7000+nm range aircraft and the 787-9 will become a 8000+mm aircraft.

Both the 787-9 and 787-10 have the same MLG including the same tiers. The MLG is comparable to the MLG on the A330. 4 wheel boogies of similar size and the same tires.
The MTOW of the 787-9/10 is 254t. The A330 has 242t moving to 251t.
I would assume that for an increase in MTOW the 787-9/10 would need a bigger MLG (is there space for a bigger MLG aka A350-900?), a reinforced wing box, or perhaps a new designed wing box to fit a bigger MLG and reinforced wings.
One should not forget, that designs are not any longer done with unnecessary over designed parts. Better analysis aloud older designs like the 777 or A330 increased capabilities during the lifetime of the design.
We should not expect similar reserves in new designs. We should rather expect new designs being designed exactly for the intended capabilities, to not carry unnecessary weight.

I don’t think they ever really have been, technology and capabilities are always improving and we haven’t suddenly reached a plateau. Most designs are improved as the modelling used to predict them becomes more accurate and the design points can be pushed in to what was previously an error margin. There will be more good tech on its way and new techniques for manufacture, we don’t necessarily know what they are yet but their effects could easily be predicted.

I believe the current modern wide bodies (787 + A350) will increase range toward the final bastions of ULH @10knm. The trouble will come with the next crop of wide bodies that will want to emulate this out of the box (as have aircraft in the past) and their growth in terms of range will be all but useless.

Fred

mjoelnir wrote:

RJMAZ wrote:

lightsaber wrote:

I agree with both assessments.

I believe the tires are also maxed out too. It is non-trivial to upgrade at this point. I'm thinking it might not be worth the effort.

Lightsaber

Actually the landing gear is relatively fine.

Here are the exact details.

787-8 uses 50" diameter 20" wide tyres on 22" wheels. The wheels are spaced 51" apart.

The 787-9/10 has 54" diameter 21" wide tyres on 23" wheels. The wheels are spaced 60" apart.

The A350-900 has the same sized tyres as the 787-9/10 but they are spaced 68" apart. This extra spacing reduces pavement loading.

The A350-1000 uses the smaller 787-8 tyres but has 6 wheels.

So the tyres can easily take the weight but it is the spacing of the wheels that are a problem. So the issue is entirely pavement loading which can limit what airports the aircraft can operate from.

The ACN pavement loading for the 787 is already extremely high but not as high as a 777-300ER. So maximum takeoff weight could be increased from a pavement loading perspective while retaining a landing gear that still physically fits.

An increased maximum takeoff weight would place greater loads on the wing, wingbox and landing gear. So everything will need to be strengthened which is par for the course.

I couldn't see a maximum takeoff weight increasing above 260T. It is worth noting Airbus regularly does small maximum takeoff weight increases but Boeing does not. So I doubt it will happen.

It would in theory be easier to bring the 787-9 up to 260T maximum takeoff weight. The 787-10 has a stronger wing than the -9 and the landing weight is higher. Boeing has already started to fit the stronger -10 parts onto the -9. So the 787-9 would have the most headroom for an increase to create a 787-9ER. Such an aircraft would be niche and it would probably be easier to make a 787-8ER.

The 787-10ER would need additiinal strengthening. The cost wouldn't be worth it.

The biggest advantage of the current 787-10 is it's extremely low empty weight for its cabin area. This gives it excellent efficiency at medium haul. Any maximum takeoff weight increase would add empty weight and reduce its biggest advantage.

Maximum takeoff weights increases are short term thinking. In the medium term, engine improvements give you extra range. In 10 years time we'll be discussing the 787NEO. The engines will burn less fuel and the 787-10 will become a 7000+nm range aircraft and the 787-9 will become a 8000+mm aircraft.

Both the 787-9 and 787-10 have the same MLG including the same tiers. The MLG is comparable to the MLG on the A330. 4 wheel boogies of similar size and the same tires.
The MTOW of the 787-9/10 is 254t. The A330 has 242t moving to 251t.
I would assume that for an increase in MTOW the 787-9/10 would need a bigger MLG (is there space for a bigger MLG aka A350-900?), a reinforced wing box, or perhaps a new designed wing box to fit a bigger MLG and reinforced wings.
One should not forget, that designs are not any longer done with unnecessary over designed parts. Better analysis aloud older designs like the 777 or A330 increased capabilities during the lifetime of the design.
We should not expect similar reserves in new designs. We should rather expect new designs being designed exactly for the intended capabilities, to not carry unnecessary weight.

I don’t think they ever really have been, technology and capabilities are always improving and we haven’t suddenly reached a plateau. Most designs are improved as the modelling used to predict them becomes more accurate and the design points can be pushed in to what was previously an error margin. There will be more good tech on its way and new techniques for manufacture, we don’t necessarily know what they are yet but their effects could easily be predicted.

I believe the current modern wide bodies (787 + A350) will increase range toward the final bastions of ULH @10knm. The trouble will come with the next crop of wide bodies that will want to emulate this out of the box (as have aircraft in the past) and their growth in terms of range will be all but useless.

Fred

mjoelnir wrote:

RJMAZ wrote:

lightsaber wrote:

I agree with both assessments.

I believe the tires are also maxed out too. It is non-trivial to upgrade at this point. I'm thinking it might not be worth the effort.

Lightsaber

Actually the landing gear is relatively fine.

Here are the exact details.

787-8 uses 50" diameter 20" wide tyres on 22" wheels. The wheels are spaced 51" apart.

The 787-9/10 has 54" diameter 21" wide tyres on 23" wheels. The wheels are spaced 60" apart.

The A350-900 has the same sized tyres as the 787-9/10 but they are spaced 68" apart. This extra spacing reduces pavement loading.

The A350-1000 uses the smaller 787-8 tyres but has 6 wheels.

So the tyres can easily take the weight but it is the spacing of the wheels that are a problem. So the issue is entirely pavement loading which can limit what airports the aircraft can operate from.

The ACN pavement loading for the 787 is already extremely high but not as high as a 777-300ER. So maximum takeoff weight could be increased from a pavement loading perspective while retaining a landing gear that still physically fits.

An increased maximum takeoff weight would place greater loads on the wing, wingbox and landing gear. So everything will need to be strengthened which is par for the course.

I couldn't see a maximum takeoff weight increasing above 260T. It is worth noting Airbus regularly does small maximum takeoff weight increases but Boeing does not. So I doubt it will happen.

It would in theory be easier to bring the 787-9 up to 260T maximum takeoff weight. The 787-10 has a stronger wing than the -9 and the landing weight is higher. Boeing has already started to fit the stronger -10 parts onto the -9. So the 787-9 would have the most headroom for an increase to create a 787-9ER. Such an aircraft would be niche and it would probably be easier to make a 787-8ER.

The 787-10ER would need additiinal strengthening. The cost wouldn't be worth it.

The biggest advantage of the current 787-10 is it's extremely low empty weight for its cabin area. This gives it excellent efficiency at medium haul. Any maximum takeoff weight increase would add empty weight and reduce its biggest advantage.

Maximum takeoff weights increases are short term thinking. In the medium term, engine improvements give you extra range. In 10 years time we'll be discussing the 787NEO. The engines will burn less fuel and the 787-10 will become a 7000+nm range aircraft and the 787-9 will become a 8000+mm aircraft.

Both the 787-9 and 787-10 have the same MLG including the same tiers. The MLG is comparable to the MLG on the A330. 4 wheel boogies of similar size and the same tires.
The MTOW of the 787-9/10 is 254t. The A330 has 242t moving to 251t.
I would assume that for an increase in MTOW the 787-9/10 would need a bigger MLG (is there space for a bigger MLG aka A350-900?), a reinforced wing box, or perhaps a new designed wing box to fit a bigger MLG and reinforced wings.
One should not forget, that designs are not any longer done with unnecessary over designed parts. Better analysis aloud older designs like the 777 or A330 increased capabilities during the lifetime of the design.
We should not expect similar reserves in new designs. We should rather expect new designs being designed exactly for the intended capabilities, to not carry unnecessary weight.

I don’t think they ever really have been, technology and capabilities are always improving and we haven’t suddenly reached a plateau. Most designs are improved as the modelling used to predict them becomes more accurate and the design points can be pushed in to what was previously an error margin. There will be more good tech on its way and new techniques for manufacture, we don’t necessarily know what they are yet but their effects could easily be predicted.

I believe the current modern wide bodies (787 + A350) will increase range toward the final bastions of ULH @10knm. The trouble will come with the next crop of wide bodies that will want to emulate this out of the box (as have aircraft in the past) and their growth in terms of range will be all but useless.

Fred

mjoelnir wrote:

Newbiepilot wrote:

mjoelnir wrote:

The 787-10 is a simple stretch of the 787-9. It did not only exchange just range, but also payload for a higher passenger capacity. If one looks at LCC or ULCC the 787-10 has the same max passenger numbers as the A330-900.

Are you referring to the 787-10 and A330-900 having the same exit door limit of 440 seats? In practicality, very few airlines approach the max capacity of 440seats on the A330neo.

For Singapore Airlines, the 787-10 has 50 more seats. Except for a few extreme configurations like Cebu Pacific and Lion Air which represent only about a dozen airplanes, most LCCs cap A330 capacity to about 375 seats like Air Transat, Air AsiaX, Corsair, etc. For airlines like that and traditional airlines with 2 or 3 class service, I would expect the 787-10 to have around 50 more seats.

Some airlines do. I would hardly call Singapore Airlines an LCC or ULCC. CEBU pacific does 436, pretty near to the exit limit and Lion Air does exactly the limit 440 pax. I expect LCC or ULCC not doing long haul, but short to medium haul on wide bodies, to go near the exit limit.

Some airlines do what?
just to restate what was said above, Cebu and Lion only account for 11 total A330 in such dense configurations. That's not nearly enough to influence broad markets. Until such time as many more routes are being flown with such configs (signifying paying public acceptance), its not inaccurate to characterize 787-10 as a higher capacity plane. Your (future) expectation of max density A330 flying isn't a given.

flipdewaf wrote:

mjoelnir wrote:

RJMAZ wrote:

Actually the landing gear is relatively fine.

Here are the exact details.

787-8 uses 50" diameter 20" wide tyres on 22" wheels. The wheels are spaced 51" apart.

The 787-9/10 has 54" diameter 21" wide tyres on 23" wheels. The wheels are spaced 60" apart.

The A350-900 has the same sized tyres as the 787-9/10 but they are spaced 68" apart. This extra spacing reduces pavement loading.

The A350-1000 uses the smaller 787-8 tyres but has 6 wheels.

So the tyres can easily take the weight but it is the spacing of the wheels that are a problem. So the issue is entirely pavement loading which can limit what airports the aircraft can operate from.

The ACN pavement loading for the 787 is already extremely high but not as high as a 777-300ER. So maximum takeoff weight could be increased from a pavement loading perspective while retaining a landing gear that still physically fits.

An increased maximum takeoff weight would place greater loads on the wing, wingbox and landing gear. So everything will need to be strengthened which is par for the course.

I couldn't see a maximum takeoff weight increasing above 260T. It is worth noting Airbus regularly does small maximum takeoff weight increases but Boeing does not. So I doubt it will happen.

It would in theory be easier to bring the 787-9 up to 260T maximum takeoff weight. The 787-10 has a stronger wing than the -9 and the landing weight is higher. Boeing has already started to fit the stronger -10 parts onto the -9. So the 787-9 would have the most headroom for an increase to create a 787-9ER. Such an aircraft would be niche and it would probably be easier to make a 787-8ER.

The 787-10ER would need additiinal strengthening. The cost wouldn't be worth it.

The biggest advantage of the current 787-10 is it's extremely low empty weight for its cabin area. This gives it excellent efficiency at medium haul. Any maximum takeoff weight increase would add empty weight and reduce its biggest advantage.

Maximum takeoff weights increases are short term thinking. In the medium term, engine improvements give you extra range. In 10 years time we'll be discussing the 787NEO. The engines will burn less fuel and the 787-10 will become a 7000+nm range aircraft and the 787-9 will become a 8000+mm aircraft.

Both the 787-9 and 787-10 have the same MLG including the same tiers. The MLG is comparable to the MLG on the A330. 4 wheel boogies of similar size and the same tires.
The MTOW of the 787-9/10 is 254t. The A330 has 242t moving to 251t.
I would assume that for an increase in MTOW the 787-9/10 would need a bigger MLG (is there space for a bigger MLG aka A350-900?), a reinforced wing box, or perhaps a new designed wing box to fit a bigger MLG and reinforced wings.
One should not forget, that designs are not any longer done with unnecessary over designed parts. Better analysis aloud older designs like the 777 or A330 increased capabilities during the lifetime of the design.
We should not expect similar reserves in new designs. We should rather expect new designs being designed exactly for the intended capabilities, to not carry unnecessary weight.

I don’t think they ever really have been, technology and capabilities are always improving and we haven’t suddenly reached a plateau. Most designs are improved as the modelling used to predict them becomes more accurate and the design points can be pushed in to what was previously an error margin. There will be more good tech on its way and new techniques for manufacture, we don’t necessarily know what they are yet but their effects could easily be predicted.

I believe the current modern wide bodies (787 + A350) will increase range toward the final bastions of ULH @10knm. The trouble will come with the next crop of wide bodies that will want to emulate this out of the box (as have aircraft in the past) and their growth in terms of range will be all but useless.

Fred

Here we are talking about increasing the MTOW. Just for comparison, the 777 started out with an MTOW of 247 t. But used a 6 wheel bogie that grew to carry 351 t in the end.
The 787-9/10 starts out with a 4 wheel bogie that is about maxed out regarding the 254 t MTOW.

If you are of the school the 777-200ER/A350-900 really fill a niche, the 787-10 just fine on payload-range.

Tthe 777-8 might compensate its high OEW / cost by payload-range, although there are no indication of it yet.


source: https://www.henrylam.com.au/#0

Myself I definitely see a bigger wing for the 787 family in the next decade. There a capacity / CASM gab between 787-9 and 777-9 IMO.

The 787-10 / 777-8 will simply have a hard time against the A350-900 and -1000 in the 77W replacement market.

I'm not of the 787-9 "small is fine" believers in a growing markets. I just don't see airlines downscaling from the 772ER from Asia for the next 20 years.

lightsaber wrote:

Polot wrote:

787 MLG are currently maxed out at current MTOW. I think there is still room with the wing.

I agree with both assessments.

I believe the tires are also maxed out too. It is non-trivial to upgrade at this point. I'm thinking it might not be worth the effort.

Lightsaber

The wing may have some room left for additional MTOW (wingloading of ~138 lbs/ft^2, vs. the 777-300ER at ~165 lbs/ft^2), but the engines are definitely a limitation. It's current thrust-to-weight ratio is already among the lowest of of the Boeing lineup, ~0.27 by my math, so you would probably need more power in order to maintain some semblance of takeoff performance - or need 3 mile long runways.

Lightsaber wrote:

Yes, the A359 will have better economics on mission with great circle distances over 4500nm. Below 4000nm on the the 787-10 has a major advantage.

I assume you mean that A359's economics will be better on long missions because it can carry cargo?
Per Bjorn at Leeham, 78X is better on a 5,000nm mission. https://leehamnews.com/2017/11/16/data- ... ce-787-10/

As a theoretical matter, there could be a crossover in relative fuel efficiency between a lighter, shorter-range plane and a heavier, longer-range plane. As a practical matter, unless we're talking planes of totally different generations it's hard to see a material *relative* difference in per-pax-only economics at varying stage lengths across different planes.

Instead of an MTOW increase, I'd like to see Boeing extend the wingtips of -9/-10 as was originally planned but cancelled during the production debacle.
A330NEO saves up to 4% fuel due to tip extensions; Boeing could probably replicate that with 787 at least: CFRP wingtip extensions are structurally cheaper than metal tips (and attendant wing strengthening). There's no tech reason for the A330 to have significantly greater AR than 787.
I would guess management aversion to further 787 R&D right now, however, as they're focused on cash flow narrative during the earnings calls.

But if Boeing saved 4% fuel they could charge ~5% more per frame and still have a better product.
That means ~$5mn more per sale, which means marginal profit over 500 sales is $2.5bn. That's before counting an increase in sales/demand.

I think the 787-9 & 10 are not having any derivatives for at least a decade. Engines will need to be significantly better than today in both performance and reliability to make it worth it. The 777 had the 300ER model out about 8 years after the first 300, and the current 777-X program is about 15 years after that.

Boeing will start thinking about it when the line starts to slow back to 10/month. Why mess with something that is right in the sweet spot.

Matt6461 wrote:

Lightsaber wrote:

Yes, the A359 will have better economics on mission with great circle distances over 4500nm. Below 4000nm on the the 787-10 has a major advantage.

I assume you mean that A359's economics will be better on long missions because it can carry cargo?
Per Bjorn at Leeham, 78X is better on a 5,000nm mission. https://leehamnews.com/2017/11/16/data- ... ce-787-10/

As a theoretical matter, there could be a crossover in relative fuel efficiency between a lighter, shorter-range plane and a heavier, longer-range plane. As a practical matter, unless we're talking planes of totally different generations it's hard to see a material *relative* difference in per-pax-only economics at varying stage lengths across different planes.

I assumed wjinds and ATC increasing flight time.

If the dividing line is 500nm further out do to differences in assumptions... Eh. I cannot get excited over small differences as sales or financing terms matter more.

Lightsaber

I've heard from folks with the 787 program that the undercarriage was designed for a 255,000kg limit, which is where we are now at with the Maximum Taxi Weight of the 787-9 and 787-10. The same folks have said the wing (with requisite strengthening) could support TOWs north of 290,000kg.

There has long been speculation on this forum that Boeing might consider a six-wheel truck assuming it could either fit within the current Section 45 main landing gear wheel well or of that well could be expanded to accommodate it.

At this point, it seems to be that Boeing feels the 777 platform offers better opportunity than the 787 platform in terms of development for high-capacity long-range airframes so I do not expect to see Boeing pursue further significant Operating Weight increases for the 787-9 or 787-10.

keesje wrote:

I'm not of the 787-9 "small is fine" believers in a growing markets. I just don't see airlines downscaling from the 772ER from Asia for the next 20 years.

I remember you sharing that opinion a number of times in the AA 777-200ER thread before they cancelled the A350 order and selected the 787. Some airlines will choose the 787-9 and others will choose the A350-900 for transpacific flying. No one plane is perfect for every mission

From this thread:
viewtopic.php?f=3&t=1373579

keesje wrote:

It seems this post was well timed.

I think in this trade-off we shouldn't ignore the A350 is the must-have 300-350 seats /8000NM platform at this stage. AA & Leahy know all the numbers. It seems AA is negotiating price via the press.

...

The A350s offer more payload-range, comfort, bigger wings for hot airports and a growth option (-1000) for Asian flights. The 787-9 & -10 are better dimensioned for America's and Europe in this case.
.

The payload range of the A350 attractive over longer missions, but as we can tell from the number of 787-8s and 787-9s flying transpacific, the 787-9 is not only for the Americas and Europe. It can do transpacific.

The 787-10 certainly could be made to fly longer with higher MTOWs, but I think its simple stretch design is advantageous because it is one of the only widebodies built for the short to medium range high capacity markets.

keesje wrote:

The 787-10 / 777-8 will simply have a hard time against the A350-900 and -1000 in the 77W replacement market.

I'm not of the 787-9 "small is fine" believers in a growing markets. I just don't see airlines downscaling from the 772ER from Asia for the next 20 years.

Airlines can and will upscale or downscale by more than 5% if the economics work. You assume the airlines limit themselves to identical replacements but that couldn't be further from the truth.

We've already seen A330's being replaced with A321's now that they can comfortably fly 3500+nm. This is a massive downscale. We've seen 767's being replaced by 787's which is a massive upscale.

The 787 and 777X families cover a wider spread of the market than the A330NEO and A350.

The most efficient 9000nm aircraft? The 777-8
The most efficient 4000nm aircraft? The 787-10
The aircraft with the lowest trip cost? The 787-8
The aircraft with the largest capacity? The 777-9

Boeing have placed it's models to cover niches. Each aircraft has a strong advantage but also many small weaknesses. While Airbus has created very good all rounders. Each aircraft has no major advantages but also minimal weaknesses.

A mixed fleet of A330-900, A350-900's and A350-1000 provide similar CASM and range performance with just a slight incremental capacity increase. You'd be better off picking one model.

A mixed fleet of 787 and 777X's allows you to take advantage of the strengths by placing it on the correct routes. If an airline had many short thick routes, thin long routes, long thick routes or ultra long haul routes then they can pick the correct mix. The advantages outweighs the costs of the mixed fleet.

JayinKitsap wrote:

I think the 787-9 & 10 are not having any derivatives for at least a decade. Engines will need to be significantly better than today in both performance and reliability to make it worth it.

Yes, and to back that up Boeing are currently working on a new "shorter" nacelle design, which they say is necessary for engines with larger diameter fan and smaller cores.
The engine with the shorter nacelle is already being tested, and it is a Trent 1000.

Ultrafan candidate?


Ruscoe

Matt6461 wrote:

Instead of an MTOW increase, I'd like to see Boeing extend the wingtips of -9/-10 as was originally planned but cancelled during the production debacle.
A330NEO saves up to 4% fuel due to tip extensions; Boeing could probably replicate that with 787 at least: CFRP wingtip extensions are structurally cheaper than metal tips (and attendant wing strengthening). There's no tech reason for the A330 to have significantly greater AR than 787.

I seem to recall part of the problem was that the 789 was already hard up against the MTOW limit... meaning that the additional weight of tip extensions meant that fuel upload would have had to be reduced by a corresponding amount. Though I guess a ~4% fuel saving would outweigh the extra wingtip weight on all but the shortest trips.

tealnz wrote:

I seem to recall part of the problem was that the 789 was already hard up against the MTOW limit... meaning that the additional weight of tip extensions meant that fuel upload would have had to be reduced by a corresponding amount. Though I guess a ~4% fuel saving would outweigh the extra wingtip weight on all but the shortest trips.

Boeing's data showed that the better aerodynamic efficiency of going with the 1.5m longer wingtips originally planed for the 787-9 (so 3m total span extension) was effectively negated by the 1800kg of extra weight they added. Also, by adopting the same wing (with strengthening as needed to support the higher operating weights), it simplified the wing production chain.

Newbiepilot wrote:

keesje wrote:

I'm not of the 787-9 "small is fine" believers in a growing markets. I just don't see airlines downscaling from the 772ER from Asia for the next 20 years.

I remember you sharing that opinion a number of times in the AA 777-200ER thread before they cancelled the A350 order and selected the 787. Some airlines will choose the 787-9 and others will choose the A350-900 for transpacific flying. No one plane is perfect for every mission

From this thread:
viewtopic.php?f=3&t=1373579

keesje wrote:

It seems this post was well timed.

I think in this trade-off we shouldn't ignore the A350 is the must-have 300-350 seats /8000NM platform at this stage. AA & Leahy know all the numbers. It seems AA is negotiating price via the press.

...

The A350s offer more payload-range, comfort, bigger wings for hot airports and a growth option (-1000) for Asian flights. The 787-9 & -10 are better dimensioned for America's and Europe in this case.
.

The payload range of the A350 attractive over longer missions, but as we can tell from the number of 787-8s and 787-9s flying transpacific, the 787-9 is not only for the Americas and Europe. It can do transpacific.

The 787-10 certainly could be made to fly longer with higher MTOWs, but I think its simple stretch design is advantageous because it is one of the only widebodies built for the short to medium range high capacity markets.

The 47 aircraft (787-8 &787-9) ordered nearly equals the amount of Airbus A330s (24) and 767s (24) that remain in the American fleet. Have AA changed their plans and they will now ordered the 787s to replace the 777 fleet? It seems you are mixing different topics here..

Stitch wrote:

tealnz wrote:

I seem to recall part of the problem was that the 789 was already hard up against the MTOW limit... meaning that the additional weight of tip extensions meant that fuel upload would have had to be reduced by a corresponding amount. Though I guess a ~4% fuel saving would outweigh the extra wingtip weight on all but the shortest trips.

Boeing's data showed that the better aerodynamic efficiency of going with the 1.5m longer wingtips originally planed for the 787-9 (so 3m total span extension) was effectively negated by the 1800kg of extra weight they added. Also, by adopting the same wing (with strengthening as needed to support the higher operating weights), it simplified the wing production chain.

Interesting. Do you have the article discussing it?

My idea is also about structural margin that usually turns up as a design matures. Some have said this won't be happening anymore with today's sophisticated design processes, but Airbus found just found margin to extend A350's effective span.

Maybe Boeing perfectly designed the wing to be just as strong as it needs to be. That doesn't seem a good intuition given everything else that went wrong in the past.