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gatibosgru
Posts: 1710
Joined: Thu Oct 18, 2007 2:48 pm

Re: Rolls Royce 3.7 Meter dia. Engine

Fri Jan 17, 2020 7:49 pm

Checklist787 wrote:
Baldr wrote:
Checklist787 wrote:

guys calm down ...

You went so far and quickly.

An A350-900neo flying 17.000 km is useless.

Venturing to want to do something other than a 777-X (A350-2000X concept) is also a suicide as I explained above it would be a VLA market.

Quite frankly I would rather see something very similar for a 787-10ERX concept.
No doubt it will serve the market better

Right?


Airbus could in the mid-term have four A350neo family members:

A350-800neo: Re-defined A358; identical length to that of the A350-1000 and MLG with four-wheel bogies; identical 280 metric tonnes MTOW to that of the A350-900.
A350-900neo: MTOW of 280 tonnes
A350-1000neo MTOW of 319-322 tonnes
A350-2000neo: 5.7 m stretch, or by 9 fuselage frames, over that of the A350-1000. MTOW of 325 tonnes -- NB: the A350-1000, in contrast, is stretched by 7 metres (i.e. 11 fuselage frames) over that of the A350-900.



you have imagination ...

Similar engines for
787 New family

Greenliner

787-10ERX: 15,200km / 2 class 323 seats.

787-11X : 2 class 350 seats 13,000km (good for Asian market) same MTOW as the 787-10 Dreamliner

787-9ERX : same MTOW as the 787-8 Dreamliner

787-8LRX : 2 class 242- seats 16,000 km.

787-FX (Freighter, same base as 787-8LRX) 9.500 km range

Realy better for the market :thumbsup:


I am absolutely shocked you'd think that line-up is better for the market, shocked I tell you!
@DadCelo
 
Checklist787
Posts: 512
Joined: Sat Jun 01, 2019 2:37 am

Re: Rolls Royce 3.7 Meter dia. Engine

Fri Jan 17, 2020 7:55 pm

gatibosgru wrote:
Checklist787 wrote:
Baldr wrote:

Airbus could in the mid-term have four A350neo family members:

A350-800neo: Re-defined A358; identical length to that of the A350-1000 and MLG with four-wheel bogies; identical 280 metric tonnes MTOW to that of the A350-900.
A350-900neo: MTOW of 280 tonnes
A350-1000neo MTOW of 319-322 tonnes
A350-2000neo: 5.7 m stretch, or by 9 fuselage frames, over that of the A350-1000. MTOW of 325 tonnes -- NB: the A350-1000, in contrast, is stretched by 7 metres (i.e. 11 fuselage frames) over that of the A350-900.



you have imagination ...

Similar engines for
787 New family

Greenliner

787-10ERX: 15,200km / 2 class 323 seats.

787-11X : 2 class 350 seats 13,000km (good for Asian market) same MTOW as the 787-10 Dreamliner

787-9ERX : same MTOW as the 787-8 Dreamliner

787-8LRX : 2 class 242- seats 16,000 km.

787-FX (Freighter, same base as 787-8LRX) 9.500 km range

Realy better for the market :thumbsup:


I am absolutely shocked you'd think that line-up is better for the market, shocked I tell you!


You haven't thought about it, have you?

Seriously new engines are ALWAYS better for the market, It's normal :)

Is it really shocking?
 
Baldr
Posts: 65
Joined: Sat Nov 23, 2019 1:10 pm

Re: Rolls Royce 3.7 Meter dia. Engine

Fri Jan 17, 2020 8:52 pm

Checklist787 wrote:
Baldr wrote:
Checklist787 wrote:

guys calm down ...

You went so far and quickly.

An A350-900neo flying 17.000 km is useless.

Venturing to want to do something other than a 777-X (A350-2000X concept) is also a suicide as I explained above it would be a VLA market.

Quite frankly I would rather see something very similar for a 787-10ERX concept.
No doubt it will serve the market better

Right?


Airbus could in the mid-term have four A350neo family members:

A350-800neo: Re-defined A358; identical length to that of the A350-1000 and MLG with four-wheel bogies; identical 280 metric tonnes MTOW to that of the A350-900.
A350-900neo: MTOW of 280 tonnes
A350-1000neo MTOW of 319-322 tonnes
A350-2000neo: 5.7 m stretch, or by 9 fuselage frames, over that of the A350-1000. MTOW of 325 tonnes -- NB: the A350-1000, in contrast, is stretched by 7 metres (i.e. 11 fuselage frames) over that of the A350-900.



you have imagination ...

Similar engines for
787 New family

Greenliner

787-10ERX: 15,200km / 2 class 323 seats.

787-11X : 2 class 350 seats 13,000km (good for Asian market) same MTOW as the 787-10 Dreamliner

787-9ERX : same MTOW as the 787-8 Dreamliner 2 class 280 seats, 15.200 km range

787-8LRX : 2 class 242- seats 16,000 km.

787-FX (Freighter, same base as 787-8LRX) 9.500 km range

Realy better for the market :thumbsup:


The 787 fuselage has more than half a metre (20 inches) lower ground clearance than the 777/777X and A350. Also, the engines on the 787 are already mounted as high on the wing as that of the 777X. Hence, the 787 has much less room for engine growth than that of the A350.

https://www.boeing.com/resources/boeingdotcom/commercial/airports/acaps/787.pdf

Now, it would appear as if your 787-10ERX would need a new, larger wing and a taller landing gear. So, if we're comparing A v B prospects with respect to future developments; why don't we look at an A350-derived, A330neo replacement (A360X) as well?

First, it's important to note that the wing for an A360X would only be Airbus's second all new composite wing while the new wing for your 787-10ERX would be Boeing's third all new composite wing. Boeing's second all new composite wing has essentially been "wasted" on the 777X.

A360X:

A) A350 cockpit, fuselage and empennage.
B) New smaller wing (i.e.wing area of 350 m2 vs 370 m2 for the A330neo and 787, 442 m2 for the A350-900, 464 m2 for the A350-1000 and 520 m2 for the 777X).
C) Wing span of 64.8 metres.
D) New and lighter nose and main landing gears.
E) New and smaller horizontal tail plane (HTP)
F) MTOW with a maximum of 220 metric tonnes; or similar to the original (pre 2004) MTOW estimates* for the 787-9 that were based on highly optimistic and significantly lower Manufacturer's Weight Empty (MWE) estimates.

*Page 12:
https://www.slideshare.net/aergenium/b787-lessons-learnt-presentation

-

A360 family designed with sufficient ground clearance for RR UltraFan engines:

A360-800: identical in size to the 787-8; MTOW of 199 metric tonnes; range of 8500 nm.
A360-900: identical in size to the 787-9; MTOW of 220 metric tonnes; range of 8500 nm
A360-1000: identical in size to the 787-10; MTOW of 220 metric tonnes; range of 7000 nm.
 
Airlines0613
Posts: 168
Joined: Thu Jan 07, 2016 6:06 am

Re: Rolls Royce 3.7 Meter dia. Engine

Fri Jan 17, 2020 8:57 pm

Baldr wrote:
Checklist787 wrote:
tommy1808 wrote:

Nope, is already FBW. No need for a pinch of FBW for the edges of the envelope.

Best regards
Thomas



Very well, But a question comes to my mind ...

How further would fly the A350-900 neo concept with these new engines?


Well, the UltraFan engine should have a 10 percent lower Thrust Specific Fuel Consumption (TSFC) than what is currently the most efficient turbofan engine -- the Trent XWB engine on the A350.

10 percent lower TSFC means roughly that you can fly 10 percent longer, or using 10 percent less fuel per flight. However, more range is not what's really needed for the A350-900.

10 percent lower TSFC means, however, that a 5.7 metre stretched A350-2000X -- i.e. stretched by 9 fuselage frames: 5 frames forward of the wing, 4 frames aft of the wing -- would not have a higher trip fuel consumption than the current A350-1000. The 79.5 metre long A350-2000X would have about the same cabin floor area as that of the 777-9, but it would have a slightly higher capacity due to the longer cabin and less wasted space in the premium cabins -- which together with a 10+ percent lower trip fuel consumption than the 777-9 would render the 777-9 totally noncompetitive (i.e. significantly lower CASM for the A350-2000X).

The most efficient turbofan currently built and in testing is the GE9X which has 5-10% lower TSFC than the Trent XWB. Literally the engine, along with the wing to a smaller extent, is what makes the Boeing 777X efficient.

Honestly, they don’t need the ultra fan, if you can stick GE9Xs on an Airbus A350neo, it would be just as capable and more efficient than the Boeing 777X.
Last edited by Airlines0613 on Fri Jan 17, 2020 9:01 pm, edited 1 time in total.
 
User avatar
Kindanew
Posts: 180
Joined: Tue May 30, 2017 11:07 pm

Re: Rolls Royce 3.7 Meter dia. Engine

Fri Jan 17, 2020 9:01 pm

Baldr wrote:
Checklist787 wrote:
Baldr wrote:

Airbus could in the mid-term have four A350neo family members:

A350-800neo: Re-defined A358; identical length to that of the A350-1000 and MLG with four-wheel bogies; identical 280 metric tonnes MTOW to that of the A350-900.
A350-900neo: MTOW of 280 tonnes
A350-1000neo MTOW of 319-322 tonnes
A350-2000neo: 5.7 m stretch, or by 9 fuselage frames, over that of the A350-1000. MTOW of 325 tonnes -- NB: the A350-1000, in contrast, is stretched by 7 metres (i.e. 11 fuselage frames) over that of the A350-900.



you have imagination ...

Similar engines for
787 New family

Greenliner

787-10ERX: 15,200km / 2 class 323 seats.

787-11X : 2 class 350 seats 13,000km (good for Asian market) same MTOW as the 787-10 Dreamliner

787-9ERX : same MTOW as the 787-8 Dreamliner 2 class 280 seats, 15.200 km range

787-8LRX : 2 class 242- seats 16,000 km.

787-FX (Freighter, same base as 787-8LRX) 9.500 km range

Realy better for the market :thumbsup:


The 787 fuselage has more than half a metre (20 inches) lower ground clearance than the 777/777X and A350. Also, the engines on the 787 are already mounted as high on the wing as that of the 777X. Hence, the 787 has much less room for engine growth than that of the A350.

https://www.boeing.com/resources/boeingdotcom/commercial/airports/acaps/787.pdf

Now, it would appear as if your 787-10ERX would need a new, larger wing and a taller landing gear. So, if we're comparing A v B prospects with respect to future developments; why don't we look at an A350-derived, A330neo replacement (A360X) as well?

First, it's important to note that the wing for an A360X would only be Airbus's second all new composite wing while the new wing for your 787-10ERX would be Boeing's third all new composite wing. Boeing's second all new composite wing has essentially been "wasted" on the 777X.

A360X:

A) A350 cockpit, fuselage and empennage.
B) New smaller wing (i.e.wing area of 350 m2 vs 370 m2 for the A330neo and 787, 442 m2 for the A350-900, 464 m2 for the A350-1000 and 520 m2 for the 777X).
C) Wing span of 64.8 metres.
D) New and lighter nose and main landing gears.
E) New and smaller horizontal tail plane (HTP)
F) MTOW with a maximum of 220 metric tonnes; or similar to the original (pre 2004) MTOW estimates* for the 787-9 that were based on highly optimistic and significantly lower Manufacturer's Weight Empty (MWE) estimates.

*Page 12:
https://www.slideshare.net/aergenium/b787-lessons-learnt-presentation

-

A360 family designed with sufficient ground clearance for RR UltraFan engines:

A360-800: identical in size to the 787-8; MTOW of 199 metric tonnes; range of 8500 nm.
A360-900: identical in size to the 787-9; MTOW of 220 metric tonnes; range of 8500 nm
A360-1000: identical in size to the 787-10; MTOW of 220 metric tonnes; range of 7000 nm.


The A400M wing is composite so the A350 is their second composite wing.
 
WayexTDI
Posts: 1483
Joined: Fri Sep 21, 2018 4:38 pm

Re: Rolls Royce 3.7 Meter dia. Engine

Fri Jan 17, 2020 9:04 pm

Checklist787 wrote:
WayexTDI wrote:
Checklist787 wrote:

guys calm down ...

You went so far and quickly.

An A350-900neo flying 17.000 km is useless.

Why is it useless? That's slightly above the Qantas Project Sunrise; so, it would appear there is a demand for it (albeit small)

Checklist787 wrote:
Venturing to want to do something other than a 777-X (A350-2000X concept) is also a suicide as I explained above it would be a VLA market.

Quite frankly I would rather see something very similar for a 787-10ERX concept.
No doubt it will serve the market better

Right?

So, the VLA market is a Boeing-exclusive one? Now that the 747 pax is gone, the crown has to be worn by the 777-9?
If Airbus can do a better product than Boeing, why deny the airlines the opportunity to buy it?


Reread yourself.
You have given yourself the answer! ;)

Maybe you should reread what I wrote, and actually what you wrote:
- ULH new variant would be based on A350-900 (hence "short fuselage");
- VLA variant would be longer than the current A350-1000 (hence, "super long fuselage")
Yes, I gave myself the answer: different variants, different missions.
 
RJMAZ
Posts: 1826
Joined: Sat Jul 09, 2016 2:54 am

Re: Rolls Royce 3.7 Meter dia. Engine

Fri Jan 17, 2020 10:11 pm

Baldr wrote:
Now, it would appear as if your 787-10ERX would need a new, larger wing and a taller landing gear.
Incorrect.

When viewed from the front the 787 engines are much closer to the main landing gear than the A350. This is what determines minimum ground clearance for cross wind landing while the aircraft is banked.

The 787 also has 78% of the thrust requirement compared to the A350 76klb vs 97klb. A 10inch fan increase on the A350 means a 7.8inch fan increase in the 787.

A new wing will not be required as the MTOW will not increase. All of the range will come from the new engines putting the range well above 7000nm.

History shows no one wants a 9000+nm range aircraft. Airlines would rather an aircraft that is lighter per square metre of cabin area with lower range. The highest selling models in the last few decades had a range around 7000nm. Both A350NEO models will exceed 9000nm range. Airlines will not really have much choice if they are an Airbus customer or an existing A350 operator.

Most here have noted the 787-10NEO will become the highest selling 787 model as it is the lightest per square metre of cabin area and it will now sit in the sweet spot for range.

Lets say Airbus made the A350-1000NEO with both the 280t MTOW and the 319t MTOW. The range would be approx 7500nm vs 9500nm. The lower MTOW aircraft would easily have an empty weight 5% lighter. The 280t version would probably outsell 5:1 as it is in the range sweetspot and is more efficient.

The current A350-1000 if it had a 280t MTOW the range it would be below 7000nm and be below the sweet spot. The newer engines makes lighter weight aircraft possible.

We have many examples where an aircraft got replaced by a lighter aircraft that got newer engines. The A321 now replacing the 757 comes to mind.
 
Baldr
Posts: 65
Joined: Sat Nov 23, 2019 1:10 pm

Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 12:04 am

Airlines0613 wrote:
Baldr wrote:
Checklist787 wrote:


Very well, But a question comes to my mind ...

How further would fly the A350-900 neo concept with these new engines?


Well, the UltraFan engine should have a 10 percent lower Thrust Specific Fuel Consumption (TSFC) than what is currently the most efficient turbofan engine -- the Trent XWB engine on the A350.

10 percent lower TSFC means roughly that you can fly 10 percent longer, or using 10 percent less fuel per flight. However, more range is not what's really needed for the A350-900.

10 percent lower TSFC means, however, that a 5.7 metre stretched A350-2000X -- i.e. stretched by 9 fuselage frames: 5 frames forward of the wing, 4 frames aft of the wing -- would not have a higher trip fuel consumption than the current A350-1000. The 79.5 metre long A350-2000X would have about the same cabin floor area as that of the 777-9, but it would have a slightly higher capacity due to the longer cabin and less wasted space in the premium cabins -- which together with a 10+ percent lower trip fuel consumption than the 777-9 would render the 777-9 totally noncompetitive (i.e. significantly lower CASM for the A350-2000X).

The most efficient turbofan currently built and in testing is the GE9X which has 5-10% lower TSFC than the Trent XWB. Literally the engine, along with the wing to a smaller extent, is what makes the Boeing 777X efficient.

Honestly, they don’t need the ultra fan, if you can stick GE9Xs on an Airbus A350neo, it would be just as capable and more efficient than the Boeing 777X.


The GE9X engine will be up to 10 percent more efficient than the GE90-115B engine on the 777-300ER. GE has been claiming that the GE9X will have a 5% improved thrust specific fuel consumption versus any twin-aisle engine at service entry (meaning the TXWB). It remains to be seen if that claim will hold true. Anyway, I thought it was quite evident that I was talking about the most efficient of the in-service turbofan engines, not about an engine that is undergoing testing and which is not yet certified.

Also, you cannot just stick the GE9X engine on the A350-1000, since the GE9X is significantly heavier than the TXWB-97 engine.

https://www.ainonline.com/aviation-news/air-transport/2017-11-09/new-testing-philosophy-will-aid-ge9x-entry-service

- link confirming that the GE9X is “a little heavier” than the GE90-115B, mainly because it has a larger fan diameter...

Now, the engine dry weights for the TXWB-97 and GE90-115B engines are 7,550 kg and 8,762 kg, respectively. So, the dry weight for the GE9X engine is likely to exceed 9,000 kg.

-

GE engineers could go so big because they designed fan blades and the fan case from the most advanced carbon fiber composites, reducing weight and cutting the number of blades from 22 to 16, compared with its predecessor, the GE90. The GE9X also includes 3D-printed fuel nozzles, parts made from light- and heat-resistant ceramic composites, and other new technologies. As a result, the engine will be also up to 10 percent more fuel-efficient than the GE90, which GE developed for the current version of the 777 jet.


https://www.ge.com/reports/away-worlds-largest-jet-engine-ge9x-takes-maiden-flight/

A blend of evolutionary and revolutionary designs will enable the GE9X to be the most fuel-efficient jet engine GE has ever produced on a per-pounds-of-thrust basis. It’s designed to deliver a 10% improved aircraft fuel burn versus the GE90-115B-powered 777-300ER and a 5% improved specific fuel consumption versus any twin-aisle engine available, plus achieve an approximate 10:1 bypass ratio, a 60:1 overall pressure ratio and margin to Stage 5 noise limits.


https://www.geaviation.com/commercial/engines/ge9x-commercial-aircraft-engine
 
Baldr
Posts: 65
Joined: Sat Nov 23, 2019 1:10 pm

Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 12:18 am

Kindanew wrote:
Baldr wrote:
Checklist787 wrote:


you have imagination ...

Similar engines for
787 New family

Greenliner

787-10ERX: 15,200km / 2 class 323 seats.

787-11X : 2 class 350 seats 13,000km (good for Asian market) same MTOW as the 787-10 Dreamliner

787-9ERX : same MTOW as the 787-8 Dreamliner 2 class 280 seats, 15.200 km range

787-8LRX : 2 class 242- seats 16,000 km.

787-FX (Freighter, same base as 787-8LRX) 9.500 km range

Realy better for the market :thumbsup:


The 787 fuselage has more than half a metre (20 inches) lower ground clearance than the 777/777X and A350. Also, the engines on the 787 are already mounted as high on the wing as that of the 777X. Hence, the 787 has much less room for engine growth than that of the A350.

https://www.boeing.com/resources/boeingdotcom/commercial/airports/acaps/787.pdf

Now, it would appear as if your 787-10ERX would need a new, larger wing and a taller landing gear. So, if we're comparing A v B prospects with respect to future developments; why don't we look at an A350-derived, A330neo replacement (A360X) as well?

First, it's important to note that the wing for an A360X would only be Airbus's second all new composite wing while the new wing for your 787-10ERX would be Boeing's third all new composite wing. Boeing's second all new composite wing has essentially been "wasted" on the 777X.

A360X:

A) A350 cockpit, fuselage and empennage.
B) New smaller wing (i.e.wing area of 350 m2 vs 370 m2 for the A330neo and 787, 442 m2 for the A350-900, 464 m2 for the A350-1000 and 520 m2 for the 777X).
C) Wing span of 64.8 metres.
D) New and lighter nose and main landing gears.
E) New and smaller horizontal tail plane (HTP)
F) MTOW with a maximum of 220 metric tonnes; or similar to the original (pre 2004) MTOW estimates* for the 787-9 that were based on highly optimistic and significantly lower Manufacturer's Weight Empty (MWE) estimates.

*Page 12:
https://www.slideshare.net/aergenium/b787-lessons-learnt-presentation

-

A360 family designed with sufficient ground clearance for RR UltraFan engines:

A360-800: identical in size to the 787-8; MTOW of 199 metric tonnes; range of 8500 nm.
A360-900: identical in size to the 787-9; MTOW of 220 metric tonnes; range of 8500 nm
A360-1000: identical in size to the 787-10; MTOW of 220 metric tonnes; range of 7000 nm.


The A400M wing is composite so the A350 is their second composite wing.


I was talking about civilian airliners.

Boeing was a prime subcontractor on the B-2A bomber and built the outer CFRP wing for the aircraft.

Hence, if military aircraft would be included, the 787 wing (i.e. designed by Boeing, but manufactured by Japan's Mitsubishi Heavy Industries Ltd) would be Boeing's second CFRP wing.
 
Baldr
Posts: 65
Joined: Sat Nov 23, 2019 1:10 pm

Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 1:37 am

RJMAZ wrote:
Baldr wrote:
Now, it would appear as if your 787-10ERX would need a new, larger wing and a taller landing gear.
Incorrect.

When viewed from the front the 787 engines are much closer to the main landing gear than the A350. This is what determines minimum ground clearance for cross wind landing while the aircraft is banked.

The 787 also has 78% of the thrust requirement compared to the A350 76klb vs 97klb. A 10inch fan increase on the A350 means a 7.8inch fan increase in the 787.

A new wing will not be required as the MTOW will not increase. All of the range will come from the new engines putting the range well above 7000nm.

History shows no one wants a 9000+nm range aircraft. Airlines would rather an aircraft that is lighter per square metre of cabin area with lower range. The highest selling models in the last few decades had a range around 7000nm. Both A350NEO models will exceed 9000nm range. Airlines will not really have much choice if they are an Airbus customer or an existing A350 operator.

Most here have noted the 787-10NEO will become the highest selling 787 model as it is the lightest per square metre of cabin area and it will now sit in the sweet spot for range.

Lets say Airbus made the A350-1000NEO with both the 280t MTOW and the 319t MTOW. The range would be approx 7500nm vs 9500nm. The lower MTOW aircraft would easily have an empty weight 5% lighter. The 280t version would probably outsell 5:1 as it is in the range sweetspot and is more efficient.

The current A350-1000 if it had a 280t MTOW the range it would be below 7000nm and be below the sweet spot. The newer engines makes lighter weight aircraft possible.

We have many examples where an aircraft got replaced by a lighter aircraft that got newer engines. The A321 now replacing the 757 comes to mind.


I can't see where I'm supposedly "incorrect".

RJMAZ wrote: When viewed from the front the 787 engines are much closer to the main landing gear than the A350. This is what determines minimum ground clearance for cross wind landing while the aircraft is banked.


Distance between engine centre-line and the fuselage centre-line:

77L/77W: 9.61 m
787: 9.73 m
A350: 10.5 m
777X: 10.64 m

Hence, your assertion doesn't make any sense. The fact of the matter is that the overall ground clearance is significantly lower for the 787 when compared to the 77L/77W, 777X and A350.

And why did Boeing decide to move the engines -- that have a nacelle diameter of 174 inches -- on the 777X further outboard when compared to the engine position on the 77L/77W?

Of course, in your world Boeing can put engines that have a nacelle diameter of 174 inches on the 777X, while Airbus can't do the same with the A350.

Interestingly, the distance between the centre-line of the two main landing gears on the 77L/77W is 10.97 metres, while it is 9.8 metres on the 787. Hence, the 77L/77E engines are much closer to the main landing gear than with the 787.

RJMAZ wrote: The 787 also has 78% of the thrust requirement compared to the A350 76klb vs 97klb. A 10inch fan increase on the A350 means a 7.8inch fan increase in the 787.


The TXWB fan on the A350 has a 6" greater diameter than the Trent-1000 fan on the 787 (i.e. 118" vs. 112"), while the 787 has a 20" plus (50 centimeters plus) lower overall ground clearance.

Now, according to RR, a 70,000 pounds of thrust UltraFan engine will have a fan diameter of 140 inches (15:1 bypass ratio).

https://www.mro-network.com/manufacturing-distribution/rolls-royce-runs-first-composite-fan-and-case-combo-trent-1000

So, how would you integrate an engine with a fan diameter of 140 inches and a nacelle diameter of 170 inches (assuming no variable pitch fan) on the 787?

RJMAZ wrote: A new wing will not be required as the MTOW will not increase. All of the range will come from the new engines putting the range well above 7000nm.


That comment was in response to Checklist787 who wants a 787-10ERX with a range of 15,200km (8,207 nm).

Such a capable 787-10ERX would indeed need a new and larger wing.

History shows no one wants a 9000+nm range aircraft. Airlines would rather an aircraft that is lighter per square metre of cabin area with lower range. The highest selling models in the last few decades had a range around 7000nm. Both A350NEO models will exceed 9000nm range. Airlines will not really have much choice if they are an Airbus customer or an existing A350 operator.


The UltraFan powered, 280 metric tonnes MTOW A350-800X (A350-1000 length) and the 325 metric tonnes, 79.5 metres long A350-2000, would IMJ become the best-selling members of the A350neo family. Hence, airlines will have a lot of choice if they are an Airbus customer or an existing A350 operator.

RJMAZ said: Lets say Airbus made the A350-1000NEO with both the 280t MTOW and the 319t MTOW. The range would be approx 7500nm vs 9500nm. The lower MTOW aircraft would easily have an empty weight 5% lighter. The 280t version would probably outsell 5:1 as it is in the range sweetspot and is more efficient.


IMJ, the range of an UltraFan powered, 280 metric tonnes MTOW A350-800 (A350-1000 length) would be closer to 8000 nm, while the UltraFan powered, 325 metric tonnes MTOW A350-2000 would kill off the 777-9 and take all of the 350+ seat market.

We have many examples where an aircraft got replaced by a lighter aircraft that got newer engines. The A321 now replacing the 757 comes to mind.


That's why the current 787 would be extremely vulnerable to a new A360X family (derived from the A350) as described in a comment up-thread. For example, an UltraFan powered, 220 metric tonnes A360-900X (same size as the 787-9) would have a smaller and lighter wing than the 787 (but with a higher aspect ratio) and designed with a wingbox (by far the heaviest part of the wing) that would have a significantly smaller fuel capacity (less fuel volume, less weight). Thrust requirements would be less than 60,000 pounds of thrust (vs 71,000 lbf on the 787-9); range: 8000 + nm.
 
RJMAZ
Posts: 1826
Joined: Sat Jul 09, 2016 2:54 am

Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 2:28 am

Baldr wrote:
Distance between engine centre-line and the fuselage centre-line:

You just got it wrong again.

Outer wheel to aircraft centreline.
787-9/10 425cm
A350-900 is 433cm

Engine to aircraft centreline
787-9/10 973cm
a350-900 1050cm

Now if we assume an equal maximum bank angle of 7 degrees the ground clearance of the engine can be the following.
787-9/10 67cm
A350-900 75cm

So the 787 engines can be 8cm closer to the ground than the A350 with the same risk of engine hitting the ground.

Once you combine this with the fact the 787 needs smaller engines with 80% less thrust they both have now equal ability to fit similar tech 14:1 bypass ratio engines.

This thread explains the numbers, we noted some errors in the ACAPs.
viewtopic.php?t=1429867

Baldr wrote:
That's why the current 787 would be extremely vulnerable to a new A360X family

The exact argument could be used to say how vulnerable your A360 would be to the much lighter 797. The 797 would have only 50,000lb thrust engines and the largest version will be quite close to 787-8 in size.

Optimising for lower range produces a significantly lighter aircraft and gives a huge efficiency boost up to that design range.

Your A360 numbers are also completely unrealistic.

Baldr wrote:
A360-800: identical in size to the 787-8; MTOW of 199 metric tonnes; range of 8500 nm.
A360-900: identical in size to the 787-9; MTOW of 220 metric tonnes; range of 8500 nm
A360-1000: identical in size to the 787-10; MTOW of 220 metric tonnes; range of 7000 nm.

Take your A360-1000. The 787-10 has 299m2 vs 290m2 of the A350-900. So you just proposed a 2 metre stretch of the A350-900 but with a 220t MTOW. You've reduced MTOW by 20%. A normal A350-900 would have a range of only 4000nm with a normal load taking off at 220t. Even with 10% improved engines the range would struggle to exceed 5000nm. 7000nm is absolutely ridiculous.

It would take another 50 years of engine and material improvements before a 787-10 sized cabin with 299m2 area could fly 300 passengers a distance of 7000nm at a takeoff weight of only 220t.

The 787-10 at 254t does 6430nm with 330 passengers. Look at the ACAP on what happens when you reduce MTOW by 20%, range drops to only 2500nm!!

It would be crazy for Airbus to launch the A360-1000 that had a larger cabin than their A350-900. The next Airbus aircraft family will probably be 50-100m2 smaller than the A350-900. The A330 cross section is perfect for this size.
 
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zeke
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 2:42 am

RJMAZ wrote:
You just got it wrong again.

Outer wheel to aircraft centreline.
787-9/10 425cm
A350-900 is 433cm

Engine to aircraft centreline
787-9/10 973cm
a350-900 1050cm

Now if we assume an equal maximum bank angle of 7 degrees the ground clearance of the engine can be the following.
787-9/10 67cm
A350-900 75cm


This is intellectually dishonest, we have done all these numbers before in the “What is the maximum fan diameter” thread in tech ops. You know all about it.

This is what I had posed before viewtopic.php?t=1429867

“I had a look at the spanwise centreline from the outer wheel to the spanwise centre of the engine, and the minimum height of the engine off the ground I came up with the following maximum angles which would be the landing roll angle limits.

Spanwise distance from the outer main wheel to the engine centre line (mm)

787-8 4180
787-9 4250
787-10 4050
A350-900 4330
A350-1000 4400

Minimum height of engine from ground (mm)

787-8 710
787-9 610
787-10 740
A350-900 760
A350-1000 760

Minimum angle from wheels to engine (maximum bank angle limited in landing), in degrees

787-8 9.64
787-9 8.17
787-10 10.35
A350-900 9.96
A350-1000 9.80

The most limited aircraft appears to be the 787-9.”
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speedbird52
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 2:51 am

Checklist787 wrote:
WayexTDI wrote:
Checklist787 wrote:

guys calm down ...

You went so far and quickly.

An A350-900neo flying 17.000 km is useless.

Why is it useless? That's slightly above the Qantas Project Sunrise; so, it would appear there is a demand for it (albeit small)

Checklist787 wrote:
Venturing to want to do something other than a 777-X (A350-2000X concept) is also a suicide as I explained above it would be a VLA market.

Quite frankly I would rather see something very similar for a 787-10ERX concept.
No doubt it will serve the market better

Right?

So, the VLA market is a Boeing-exclusive one? Now that the 747 pax is gone, the crown has to be worn by the 777-9?
If Airbus can do a better product than Boeing, why deny the airlines the opportunity to buy it?


Reread yourself.
You have given yourself the answer! ;)

Pretty sure the main issue with VLAs is fuel efficiency. An A350-2000 wouldn't suffer from that. A 779 really is not that much bigger than a 77W, which has sold quite well. The reason the current largest aircraft offerings aren't selling has to do with the age of the 77W fleet IMO
 
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zeke
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 2:53 am

Airlines0613 wrote:
The most efficient turbofan currently built and in testing is the GE9X which has 5-10% lower TSFC than the Trent XWB. Literally the engine, along with the wing to a smaller extent, is what makes the Boeing 777X efficient.


There is zero evidence anywhere to show the GE9X TSFC found during testing, let alone data from testing to demonstrate an advantage over the Trent XWB, which in itself is not one engine, the Trent XWB has already been through iterations or updates. Some of the updates actually have come from the Ultrafan testing, from the Advance3 engine. They used Advance3 technology in the Trent XWB-97 which was fed back into the Trent XWB-84.

The Trent XWB engine available today is not the same engine that was available when the A350 started testing.
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speedbird52
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 3:07 am

Is this the fastest an aircraft design has been re-engined? I find it incredible that a plane that was put into service just four years ago already has its replacement being designed
 
strfyr51
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 3:09 am

uta999 wrote:
With the issues that the MAX is having, and future big twins getting ever larger fans. Is it not possible to ditch the pylon altogether, and cut-away the wing and make these huge engines an integral part of the wing itself?

Possibly with the exhaust split above and below the surface.

A common engine mounting could make engine swaps easier, and make it possible to change manufacturer, because the engine would be a standard size, the front fan diameter could vary slightly by OEM.

the Pylon has isolators that protect the wing in the even of damage and Vibration. Attaching the engine directly to the wing might have been good for the Comet but they were turbojet engines with no real fan to speak of. A giant Fan of today's engines? Unheard of and really? Not a wise Idea..
 
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zeke
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 4:12 am

speedbird52 wrote:
Is this the fastest an aircraft design has been re-engined? I find it incredible that a plane that was put into service just four years ago already has its replacement being designed


I think that record will remain with the 747, it was only like a year in service between the 747-100 and 747-200. Back in 1983 the first 743 entered service, the first 744 in 1989.
Human rights lawyers are "ambulance chasers of the very worst kind.'" - Sky News
 
speedbird52
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 4:17 am

zeke wrote:
speedbird52 wrote:
Is this the fastest an aircraft design has been re-engined? I find it incredible that a plane that was put into service just four years ago already has its replacement being designed


I think that record will remain with the 747, it was only like a year in service between the 747-100 and 747-200. Back in 1983 the first 743 entered service, the first 744 in 1989.

The differences between the 100 and 200 weren't that substantial were they? I always grouped the -100 and -300 together in the same way the -200 and -300ER are grouped together.
 
Airlines0613
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 4:21 am

zeke wrote:
Airlines0613 wrote:
The most efficient turbofan currently built and in testing is the GE9X which has 5-10% lower TSFC than the Trent XWB. Literally the engine, along with the wing to a smaller extent, is what makes the Boeing 777X efficient.


There is zero evidence anywhere to show the GE9X TSFC found during testing, let alone data from testing to demonstrate an advantage over the Trent XWB, which in itself is not one engine, the Trent XWB has already been through iterations or updates. Some of the updates actually have come from the Ultrafan testing, from the Advance3 engine. They used Advance3 technology in the Trent XWB-97 which was fed back into the Trent XWB-84.

The Trent XWB engine available today is not the same engine that was available when the A350 started testing.

GE has stated that the GE9X has better fuel burn than the Trent XWB. Whether you agree with it or not doesn’t make a difference. Anything you say should be taken with a grain of salt, as you are heavily biased when it comes to the Airbus A350.
 
speedbird52
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 4:31 am

Airlines0613 wrote:
zeke wrote:
Airlines0613 wrote:
The most efficient turbofan currently built and in testing is the GE9X which has 5-10% lower TSFC than the Trent XWB. Literally the engine, along with the wing to a smaller extent, is what makes the Boeing 777X efficient.


There is zero evidence anywhere to show the GE9X TSFC found during testing, let alone data from testing to demonstrate an advantage over the Trent XWB, which in itself is not one engine, the Trent XWB has already been through iterations or updates. Some of the updates actually have come from the Ultrafan testing, from the Advance3 engine. They used Advance3 technology in the Trent XWB-97 which was fed back into the Trent XWB-84.

The Trent XWB engine available today is not the same engine that was available when the A350 started testing.

GE has stated that the GE9X has better fuel burn than the Trent XWB. Whether you agree with it or not doesn’t make a difference. Anything you say should be taken with a grain of salt, as you are heavily biased when it comes to the Airbus A350.

And GE isn't????
 
snasteve
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 4:37 am

tommy1808 wrote:
Checklist787 wrote:
Baldr wrote:


As I indicated in my previous comment, a 185 inch-diameter (4.7 m) nacelle would fit under the A350 wing if the engine is hung as high as the LEAP-1B is hung with respect to the wing on the 737 MAX.


What I understand is that it will require an MCAS system also ?


Nope, is already FBW. No need for a pinch of FBW for the edges of the envelope.

Best regards
Thomas


That isn’t to suggest that there wouldn’t be some revisions to the existing FBW flight program to do what MCAS was there for. You just wouldn’t need MCAS to do it.
 
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zeke
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 4:39 am

Airlines0613 wrote:
GE has stated that the GE9X has better fuel burn than the Trent XWB. Whether you agree with it or not doesn’t make a difference. Anything you say should be taken with a grain of salt, as you are heavily biased when it comes to the Airbus A350.


Please provide the reference where GE has said that, and also your previous claim “ The most efficient turbofan currently built and in testing is the GE9X which has 5-10% lower TSFC than the Trent XWB. ”.

I have seen no evidence or data to support this.
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seabosdca
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 4:44 am

If Airbus really wants to make the most of these, it should stretch both A350 variants by a few rows. At current lengths, they would both turn into ULH monsters vulnerable from below to a re-engined 787-10.

I'm sure there will be a re-engined 787 around the same timeframe, and both makers will need to think through the payload-range decision carefully.
 
RJMAZ
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 4:55 am

zeke wrote:
Spanwise distance from the outer main wheel to the engine centre line (mm)

787-8 4180
787-9 4250
787-10 4050
A350-900 4330
A350-1000 4400

For other members reading this. These numbers means the 787-10 engines are located closer to the fuselage than the 787-9 or the 787-10 has a wider landing gear. This is not the case as both have identical landing gear and engine placement.

The 787-9/10 does have a wider and larger landing gear compared to the 787-8. The correct 9 and 10 number should be less than the 787-8. That means the number for the 787-9 number is the typo. The 787-10 value looks correct and should be used for the 787-9.

zeke wrote:
Minimum height of engine from ground (mm)

787-8 710
787-9 610
787-10 740
A350-900 760
A350-1000 760

For other members reading this. The 787-9/10 has the same larger landing gear and all three 787 models have the same engine placement. The 787-9/10 should have slightly more clearance than the 787-8, the 787-10 value then looks accurate. Again the 787-9 has the typo.

The engine clearance between the 9 and 10 should be within 10-20mm at most due to the nose gear being slightly further forward. 610mm is clearly wrong.
 
smartplane
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 5:00 am

Airlines0613 wrote:
zeke wrote:
Airlines0613 wrote:
The most efficient turbofan currently built and in testing is the GE9X which has 5-10% lower TSFC than the Trent XWB. Literally the engine, along with the wing to a smaller extent, is what makes the Boeing 777X efficient.


There is zero evidence anywhere to show the GE9X TSFC found during testing, let alone data from testing to demonstrate an advantage over the Trent XWB, which in itself is not one engine, the Trent XWB has already been through iterations or updates. Some of the updates actually have come from the Ultrafan testing, from the Advance3 engine. They used Advance3 technology in the Trent XWB-97 which was fed back into the Trent XWB-84.

The Trent XWB engine available today is not the same engine that was available when the A350 started testing.

GE has stated that the GE9X has better fuel burn than the Trent XWB. Whether you agree with it or not doesn’t make a difference. Anything you say should be taken with a grain of salt, as you are heavily biased when it comes to the Airbus A350.

GE has been noticeably restrained on performance claims since the technical issues experienced. Remedial work was expected to impact performance, to be recovered at a later date.

Customers will see the hard numbers, including penalties, in customer sale / purchase side agreements. Jedi mind tricks won't work on that select group.
 
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Slug71
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 5:11 am

Well the Beluga XL can handle an airframe quite a bit wider than the A350. So there is that.
 
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zeke
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 5:44 am

RJMAZ wrote:
For other members reading this. These numbers means the 787-10 engines are located closer to the fuselage than the 787-9 or the 787-10 has a wider landing gear. This is not the case as both have identical landing gear and engine placement.

The 787-9/10 does have a wider and larger landing gear compared to the 787-8. The correct 9 and 10 number should be less than the 787-8. That means the number for the 787-9 number is the typo. The 787-10 value looks correct and should be used for the 787-9.


This is what the published data says, distance from the fuselage centre line to the engine
787-9 32’6” (9.91m)
787-10 31’10” (9.71m)

For a so called typo, 390” (32’6”) is 9.906 m, 382” (31’10”) is 9.7028m is extremely accurate unit conversion to the published numbers.

Image
Image
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Tokyo777
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 5:53 am

Perhaps they could solve all the issues with the T1000 before getting in a willy waving match with GE for biggest engine?
 
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zeke
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 6:08 am

Tokyo777 wrote:
Perhaps they could solve all the issues with the T1000 before getting in a willy waving match with GE for biggest engine?


That’s exactly what they have been doing. Ultrafan is not the result of one engine, it is a development process including the Advance2 and Advance3 engines, that hasbeen fed back into the Trent 1000 to make the Trent 1000 TEN

Some info on the Advance3 engine https://www.adsadvance.co.uk/rolls-royc ... power.html
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Kindanew
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 8:48 am

Baldr wrote:
Kindanew wrote:
Baldr wrote:

The 787 fuselage has more than half a metre (20 inches) lower ground clearance than the 777/777X and A350. Also, the engines on the 787 are already mounted as high on the wing as that of the 777X. Hence, the 787 has much less room for engine growth than that of the A350.

https://www.boeing.com/resources/boeingdotcom/commercial/airports/acaps/787.pdf

Now, it would appear as if your 787-10ERX would need a new, larger wing and a taller landing gear. So, if we're comparing A v B prospects with respect to future developments; why don't we look at an A350-derived, A330neo replacement (A360X) as well?

First, it's important to note that the wing for an A360X would only be Airbus's second all new composite wing while the new wing for your 787-10ERX would be Boeing's third all new composite wing. Boeing's second all new composite wing has essentially been "wasted" on the 777X.

A360X:

A) A350 cockpit, fuselage and empennage.
B) New smaller wing (i.e.wing area of 350 m2 vs 370 m2 for the A330neo and 787, 442 m2 for the A350-900, 464 m2 for the A350-1000 and 520 m2 for the 777X).
C) Wing span of 64.8 metres.
D) New and lighter nose and main landing gears.
E) New and smaller horizontal tail plane (HTP)
F) MTOW with a maximum of 220 metric tonnes; or similar to the original (pre 2004) MTOW estimates* for the 787-9 that were based on highly optimistic and significantly lower Manufacturer's Weight Empty (MWE) estimates.

*Page 12:
https://www.slideshare.net/aergenium/b787-lessons-learnt-presentation

-

A360 family designed with sufficient ground clearance for RR UltraFan engines:

A360-800: identical in size to the 787-8; MTOW of 199 metric tonnes; range of 8500 nm.
A360-900: identical in size to the 787-9; MTOW of 220 metric tonnes; range of 8500 nm
A360-1000: identical in size to the 787-10; MTOW of 220 metric tonnes; range of 7000 nm.


The A400M wing is composite so the A350 is their second composite wing.


I was talking about civilian airliners.

Boeing was a prime subcontractor on the B-2A bomber and built the outer CFRP wing for the aircraft.

Hence, if military aircraft would be included, the 787 wing (i.e. designed by Boeing, but manufactured by Japan's Mitsubishi Heavy Industries Ltd) would be Boeing's second CFRP wing.


I think in this case, civil vs military is an arbitrary distinction.

The A400M wing was designed at Airbus Filton by the same people who design all of Airbus’s other wings.

So all lessons learnt will be fed back in to future projects.
 
Checklist787
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 9:02 am

seabosdca wrote:
If Airbus really wants to make the most of these, it should stretch both A350 variants by a few rows. At current lengths, they would both turn into ULH monsters vulnerable from below to a re-engined 787-10.

I'm sure there will be a re-engined 787 around the same timeframe, and both makers will need to think through the payload-range decision carefully.


:checkmark:

Indeed, the 787 has a lot of potential. There is no doubt that Boeing designed it "cleverlyt" without any real lack of ground clearance on the 737 aircraft as some hint...

And I can testify to this for having easily and quickly thought (for example) of a family useful for the market made up not of 3 but of 5 new including a "Freighter" version of the "787-X Greenliner" quite easily and that I KNOW that the "787 Dreamliner" is already well suited to the market...

Why useful to the market?

1. Since it still targets the Gap from 242 to 323 seats even a little more extended to 350 seats with the new 787-11X extended to 72 meters long and keeping the same MTOW as the initial 787-10 and does not actually require an engine bigger than the current 787 Dreamliner family ...

2. Since that the engine of a reasonable size would constitute a state-of-the-art technology for an EIS from 2030 ...

3. A development that I will see when the FIRST "People mover" NMA-X
will be assembled in 2025-2026

Regards
 
rbavfan
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 9:47 am

Checklist787 wrote:
Baldr wrote:
RJMAZ wrote:
If 3.7m fan case diameter is the nacelle diameter then it is slightly smaller than the GE9X.

If the bypass ratio is 14:1 then with that diameter the thrust level would be perfect for the current A350NEO.

This is 100% for the A350NEO.

A 3.7m nacelle will fit under the A350 without any problems.

As I indicated in my previous comment, a 185 inch-diameter (4.7 m) nacelle would fit under the A350 wing if the engine is hung as high as the LEAP-1B is hung with respect to the wing on the 737 MAX.


What I understand is that it will require an MCAS system also ?


The 737max has larger, heavier engine mounted further forward & angled differently. If airbus moved the A350 engine fwd with similar weights & do not re angle the thrust flow. It should not cause the natural nose up issue that the 737max MCAS was needed to correct for. It's not just higher mount, weight & fwd position on the 737max that is the cause. It's far more complicated.
 
Checklist787
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 10:36 am

baldr wrote:


That comment was in response to Checklist787 who wants a 787-10ERX with a range of 15,200km (8,207 nm).

Such a capable 787-10ERX would indeed need a new and larger wing.


Since an "UltraFan" concept would bring a gain of 950nm (2,000km) on an A350-900 it is logical that on the basis of a 787-10 Dreamliner it is the same thing.

As the 787-10 Dremliner is currently scheduled to fly 13,000 km, it certainly makes sense that a 787-10ERX "UltraFan-ed" or other "state-of-the-art" technology from 2030, can fly 15,000 km with the same MTOW as the 787-9/-10 Dreamliner!

In other words, it is useless to design a (other) wing ...
 
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AirPacific747
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 11:53 am

Shouldn’t Rolls Royce fix the Trent 1000 engine before developing yet another possibly faulty engine design?
 
tommy1808
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 11:54 am

Kindanew wrote:
Baldr wrote:
Kindanew wrote:

The A400M wing is composite so the A350 is their second composite wing.


I was talking about civilian airliners.

Boeing was a prime subcontractor on the B-2A bomber and built the outer CFRP wing for the aircraft.

Hence, if military aircraft would be included, the 787 wing (i.e. designed by Boeing, but manufactured by Japan's Mitsubishi Heavy Industries Ltd) would be Boeing's second CFRP wing.


I think in this case, civil vs military is an arbitrary distinction.

The A400M wing was designed at Airbus Filton by the same people who design all of Airbus’s other wings.

So all lessons learnt will be fed back in to future projects.


And civilian certification... the A400M is a civilian aircraft, just all its users are military.

Best regards
Thomas
This Singature is a safe space......
 
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zeke
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 12:11 pm

AirPacific747 wrote:
Shouldn’t Rolls Royce fix the Trent 1000 engine before developing yet another possibly faulty engine design?


Same question was asked and answered already


zeke wrote:
Tokyo777 wrote:
Perhaps they could solve all the issues with the T1000 before getting in a willy waving match with GE for biggest engine?


That’s exactly what they have been doing. Ultrafan is not the result of one engine, it is a development process including the Advance2 and Advance3 engines, that hasbeen fed back into the Trent 1000 to make the Trent 1000 TEN

Some info on the Advance3 engine https://www.adsadvance.co.uk/rolls-royc ... power.html
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Polot
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 12:16 pm

tommy1808 wrote:
Kindanew wrote:
Baldr wrote:

I was talking about civilian airliners.

Boeing was a prime subcontractor on the B-2A bomber and built the outer CFRP wing for the aircraft.

Hence, if military aircraft would be included, the 787 wing (i.e. designed by Boeing, but manufactured by Japan's Mitsubishi Heavy Industries Ltd) would be Boeing's second CFRP wing.


I think in this case, civil vs military is an arbitrary distinction.

The A400M wing was designed at Airbus Filton by the same people who design all of Airbus’s other wings.

So all lessons learnt will be fed back in to future projects.


And civilian certification... the A400M is a civilian aircraft, just all its users are military.

Best regards
Thomas

Yes and no. The A400M is a military aircraft that was designed and certified to civilian standards. I’m not sure I would call it a “civilian aircraft” though.

zeke wrote:
For a so called typo, 390” (32’6”) is 9.906 m, 382” (31’10”) is 9.7028m is extremely accurate unit conversion to the published numbers.

I’m not sure if it is accurate or not (I’m leaning towards not though) but the diagram was likely made all in one unit and then for conversion they plugged all the the numbers they saw on the diagram into a calculator, so a typo probably would carry over in the unit conversion. Whoever was doing that probably has no idea if the numbers are accurate or not.
 
Baldr
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Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 1:14 pm

RJMAZ wrote: You just got it wrong again.


No, I didn't.

RJMAZ wrote:
Engine to aircraft centreline
787-9/10 973cm
a350-900 1050cm


I used the number for the 787-10 in the Boeing ACAPS for the 787: 9.71 m

You're just making things up and taking the value for the 787-8 (9.73 m) as gospel and using it for the 787-9/-10

Boeing's official ACAPS numbers for fuselage centre-line to engine centre-line:

787-8: 9.73 m
787-9: 9.91 m
787-10: 9.71 m

Now, I tend to believe that the fuselage centre-line to engine centre-line is the same on the 787-8/-9/-10 and, therefore, two out of the three numbers are wrong. However, unless you work for Boeing, you have no idea which number is correct -- yet, you have chosen 9.73 m to be right number while saying that I'm wrong. Go figure!

In contrast to Boeing's seemingly erroneous numbers in the 787 ACAPS, the fuselage centre-line to engine centre-line on the A320ceo family and A320neo family is identical (i.e. 5.75 m); on the A330ceo and A330neo it is identical (9.37 m); and on the A350-900 and A350-1000 it is identical (10.5 m).

What would the 787 gain in efficiency by not having identical engine positions for the 787-8/-9/-10?

If, in fact, the 787 does have three unique engine positions for each of the 787-8/-9/-10, the certification costs would not only have been higher than for one common engine position, but the manufacturing costs would increase as well.

RJMAZ said: Now if we assume an equal maximum bank angle of 7 degrees the ground clearance of the engine can be the following.
787-9/10 67cm
A350-900 75cm

So the 787 engines can be 8cm closer to the ground than the A350 with the same risk of engine hitting the ground.


This is getting ridiculous.

The point of attachment of the pylon box to the aircraft wing box is more than 60 cm closer (24 inches) to the ground on the 787 than on the A350 and 777X. That's by far the most important metric in order to determine the growth potential in engine size for the 787 and A350.

And it's a matter of fact that the 787 engines are hung much higher on the wing than the engines on the A350 -- you can just take a look at the drawings in the 787 and A350 ACAPS documents and see the difference and that the A350 engine is hung significantly lower with respect to the wing.

Once you combine this with the fact the 787 needs smaller engines with 80% less thrust they both have now equal ability to fit similar tech 14:1 bypass ratio engines.


Why do you keep comparing the engine thrust requirements for the 787 with the A350-1000 and not with the A350-900?

The 787 (-10) has 10 percent less thrust than the A350-900.

And once again, you seem to be unable to grasp that the point of attachment of the pylon box to the aircraft wing box is more than 60 cm closer (>24 inches) to the ground on the 787 than on the A350 and 777X.

Also, you've not answered my question why Boeing decided to move the engines on the 777X further outboard.

As I've already pointed out, the 777X nacelle diameter is 174 inches (4.42 m) and as the "ground clearance" for the point of attachment of the pylon box to the aircraft wing box is similar on the A350 and 777X, the fan diameter for new engines on the A350 can be more than 20 inches wider than what would be possible for a re-engined 787.

That's why the current 787 would be extremely vulnerable to a new A360X familyThe exact argument could be used to say how vulnerable your A360 would be to the much lighter 797. The 797 would have only 50,000lb thrust engines and the largest version will be quite close to 787-8 in size. Optimising for lower range produces a significantly lighter aircraft and gives a huge efficiency boost up to that design range. Your A360 numbers are also completely unrealistic.


The A360X family would replace the A330neo and primarily compete with an upgraded 787 family.

The 797 family would have much less range than an A360X family. The 797 family would also have much less cargo capability than the A360X family. In conclusion: Two very different aircraft serving different markets requirements (i.e. Asian airlines do seem to like LD-3 capable cargo holds on short and medium range routes, North American airlines, not so much).

As for weight estimates, the fact of the matter is that Boeing dramatically overshot their weight targets for the 787 as can be seen in this document:

Airbus dossier: 787 Lessons Learnt (October 2008)
https://www.slideshare.net/aergenium/b787-lessons-learnt-presentation

On page 12 in the document:

Design________Key Date_____MZFW*___MTOW*____MWE*____Range**
7E7 stretch____July 2003_____163.8_____219.8______93.8______7500
7E7-9_________June 2004____167.8_____230.0______98.5______7970
787-9_________April 2008_____181.4_____247.2_____108.4______6810

*Weights in metric tonnes
** Range in nautical miles

Take your A360-1000. The 787-10 has 299m2 vs 290m2 of the A350-900. So you just proposed a 2 metre stretch of the A350-900 but with a 220t MTOW. You've reduced MTOW by 20%. A normal A350-900 would have a range of only 4000nm with a normal load taking off at 220t. Even with 10% improved engines the range would struggle to exceed 5000nm. 7000nm is absolutely ridiculous.


The A360 wing would have a 25 percent smaller wing area than the A350 and 10 percent smaller wing area than the 787. The wingbox could be designed with a maximum fuel capacity of, say, 95,000 litres -- vs. 126,400 litres on the 787 and 165,000 litres on the A350. Less fuel volume means less weight, right? The A360-900X would be designed to fly for no more than 15 hours (maximum). In contrast, the current A350-900 can be in the air for nearly 20 hours.

However, the A360 wing would have the same span as the current A350 wing (64.8 m), so the aspect ratio of the A360X wing would be 30+ percent larger than the A350 wing; but still, only a 12 percent larger aspect ratio than the A330neo wing, which BTW has a higher wing aspect ratio than any other wide body. That's quite ironic, isn't it, when considering the fact that the A330 wing is not a composite wing.

Since the wing assembly typically accounts for up to 40 percent of MWE, it's obvious that the A360 wing would weigh significantly less (>10 metric tonnes) than the A350 wing, while being 10+ percent more efficient (i.e. significantly less induced drag). Add a smaller horizontal tail plane, smaller and lighter landing gear (etc.) optimised for a 220 metric tonnes MTOW and a 10 percent lower TSFC for the smaller and lighter engines -- and with a rule-of-thumb that a reduction in fuel consumption on long range aircraft of about 0.75% results from each 1% reduction in weight -- you would have an A360-900X (same size as the 787-9) burning some 30 percent less fuel per trip than the current A350-900. Since fuel weight typically accounts for 50 percent of the MTOW for long range wide-bodies -- that's 15 percent lower MTOW than the A350-900 right there (i.e. in a first order approximation).

In fact, my MWE estimates for the A360X are quite similar to the early MWE weight estimates for the 7E7/787; the difference being, of course, some 20 years of advances in technology separating the launch of the 787 and the A360X (i.e. assuming an A360X launch in 2025).

It would be crazy for Airbus to launch the A360-1000 that had a larger cabin than their A350-900. The next Airbus aircraft family will probably be 50-100m2 smaller than the A350-900. The A330 cross section is perfect for this size


As I've earlier indicated; the best-seller of the A350neo family would be the A350-800neo (i.e. A350-1000 length) and the A350-2000neo.

What Airbus could do, though, with the A350neo, is to significantly improve the efficiency of its wing. The wing outboard of the engines could be re-designed in order to increase wing span to 75 metres. That would increase the aspect ratio by 25 percent. Of course, in order to maintain Category E requirements, the re-designed wing would be designed with 2 x 5 metre long folding wing tips. So, with new UltraFan engines and a much improved wing, the A350neo would lower fuel consumption by more than 15 percent over that of the current A350.

An extra bonus with the much higher aspect ratio wing would be lower take-off thrust requirements (due to the significantly lower induced drag at take-off). Hence, the thrust required for an A350-2000neo at a MTOW of 325 metric tonnes should be no more than the 97,000 lbf of thrust on the current A350-1000. Similarly, the maximum take-off thrust of the current A350-900 would be reduced to less than 80,000 lbf of thrust.
 
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zeke
Posts: 14649
Joined: Thu Dec 14, 2006 1:42 pm

Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 1:51 pm

Polot wrote:
I’m not sure if it is accurate or not (I’m leaning towards not though) but the diagram was likely made all in one unit and then for conversion they plugged all the the numbers they saw on the diagram into a calculator, so a typo probably would carry over in the unit conversion. Whoever was doing that probably has no idea if the numbers are accurate or not.


The views including dimensions would come straight from of the 3D CATiA model.
Human rights lawyers are "ambulance chasers of the very worst kind.'" - Sky News
 
Waterbomber2
Posts: 734
Joined: Mon Feb 04, 2019 3:44 am

Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 3:34 pm

keesje wrote:
GEUltraFan9XGTF wrote:
Checklist787 wrote:


Very well, But a question comes to my mind ...

How further would fly the A350-900 neo concept with these new engines?


The A388 needs 168k lbf per wing. UltraFan is supposed to be up to 100K lbf. Still 68k lbf short. Unless you want to still use four of them for an A389 or A38K.


If 1 engine fails at V1, on a A380, it still has 210k lbs left to clear the fence at MTOW.

If one of 2 engines on a twin engined variant would fail, that also should be available (even more; asymetrical).


The A380 has an excessive MTOW for most of its missions. If fuel burn can be lowered significantly using newer engines, the MTOW requirements would decrease even further.

A combo of 2 Ultrafans plus 2 uprated PW1000G's and 25% lower 450ton MTOW may do the trick. Still a quad, but it would burn like 7-8 tons per hour, about as much as a B77W. Engine commonality with the A350 and A321 would be a selling point for the engine manufacturers and airlines alike.

I tell you, Airbus leadership needs to rethink their whole let's-throw-the-A380-to-the-garbage-bin strategy.
 
jetlaggedAF
Posts: 8
Joined: Sun Dec 29, 2019 5:34 pm

Re: Rolls Royce 3.7 Meter dia. Engine

Sat Jan 18, 2020 5:04 pm

This would be a monster of an engine - that diameter is bigger than narrow body cabins. I wouldn't be too concerned about the fit on a future A350neo. Airbus and RR aren't incompetent and full fbw makes relocating the engine fairly trivial if required without needing any mcas type hack.

I wouldn't be too quick to dismiss the need for 9000+ nm class aircraft. The only reason they haven't caught on much yet is that the existing solutions are too compromised in one way or another. They're usually mtow limited or need an extra fuel tank that takes away from cargo space. My personal view is that there will be a growing market for such aircraft once a completely unrestricted solution is available. Beyond the small but growing need for such aircraft on Aus/NZ routes I see ultra long range non stops to South and South East Asia from North America as the next target market for ULR flights. These markets are currently dominated by EK/QR/BA/LH/AF/SQ offering one stop connections via a hub but as incomes gradually improve and business travel expands, I could see somebody (probably one of the US3) seriously consider a full on attack on this market if the right equipment was available. Yes a 77L or 359 or 789 could do some of these routes already but they'd be very weight limited and restricted to flying relatively short routes like JFK-DEL. To be competitive on a route like IAH-BLR-IAH you'd need something able to fly 9000+ miles with a full load and a good number of J and Y passengers.

This is my first post on these boards. Thank you for reading.

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