B 787 vs A350

Sounds like bad reporting. Some digging around found articles with the same quotation regarding fuel, but I found another one that sounds more likely:

Paris Air Show all set for Airbus, Boeing showdown

Edit: And another...

http://www.ft.com/cms/s/0/4c5f4f86-cebc-11e2-8e16-00144feab7de.html#axzz2WD1KMCqq

 

As usual, AB is spouting pie in the sky stuff. Several weeks ago I attended a technical briefing by en executive in charge of comparative analysis. One of the slides showed the A350 planform overlaid on the 777-300ER planform. You could hardly differentiate which outline you were looking at. They were almost identical. One point that struck me was that AB's " composite A350 " is not filament wound but laid- up in panels and fastened to the frame like any other aluminum airplane, adding to the weight. After viewing the first A350 takeoff I can see Boeing written all over the A350 configuration : the nose , windshield, wing/body fairings, wing tips, strut fairings, and flaps. Their performance improvement figures are way over stated.

 

Excuse my ignorance, but would the majority of the fuel burn savings not have come from the engine manufacturer ?? I understand weight and aerodynamic issues of course, but I suspect RR and GE have been trying to save fuel for years.

Nice for airbus that they have just launched a plane they think is better than something Boeing have had in service for 25 years. Way to stay on the cutting edge

 

Yep...

Another great example: For Airbus, Big A340s Pose Risks - WSJ.com

Basically a story on how much of a dog the Airbus 340 series was (tied to the -500/600 series). These planes aren't even that old, yet they sell for less than a Boeing 747-400 that is twice as old does. All the financial guarantees that Airbus had to make to sell the plane.

The point? Take aircraft manufacturer spiels lightly...there's some truth, but there's a whole lotta' spin doctoring.

 

"The 777 is 'a much better airplane,' Airbus Chief Commercial Officer John Leahy conceded at a conference earlier this year."

That's something I never thought I'd hear from Airbus!

Supposedly, Delta's pilots and flight attendants all despise the Airbuses they inherited in the Northwest takeover, but at this point, Delta has to hang on to them just for capacity; even the 717s they will be getting from AirTran won't help.

 

In the late 80's BOEING successfully lobbied the FAA to extend ETOPS to 180 for twinjets.

This killed the A-340, but also the DC-10/MD-11 (and did not help the 747-400 sales either).

The A-340-600 was the most comfortable plane because of the very low noise level inside.

The WSJ should have mentioned the 340 is a four-engine derivative of the 330, a very successful wide body.

 

The aerodynamic efficiency of the airplane is most important and the lack of it can kill performance no matter how good the engines are. The 777 wing configuration went through something like 55-60 iterations some of which were almost microscopic tweaks of the shape. there are numerous airfoils from root to tip and things like taper ratio, thickness position, closure ratios and many other things are constantly being massaged. Same for everything else on the airframe.

 

Why is the A340 not liked?

The article doesn't explain it.


Kai

 

Other things being equal, it appears that two big engines will always be more thrifty than four smaller ones, which is why the A330, otherwise quite similar to the A340, is still in favor.

 

Bypass ratio drives fuel efficiency of these type of aircraft, period.

You can tweak the airframe six ways to Sunday and you are talking about a few tenths of a percent in fuel efficiency. Airframes are really efficient and have been for a long time. While it is important to get as much as you can from every aspect to have a performance advantage (and that's why the airframers do it), there is more available in improving the overall performance by increasing engine efficiency than there is in improving airframe efficiency.

Two big higher bypass ratio engines are a lot more efficient than four smaller, lower bypass ratio engines and that is why the 340 sucks fuel like there was no tomorrow.

This is why the Pratt is going to a geared fan, this will allow a higher bypass ratio with a smaller higher speed LP turbine and that will provide the next jump in efficiency.

If it wasn't for the noise issue there wouldn't be fan engines, they would all be propfans since they are more efficient than high bypass fans.

 

I agree 100% re engines. What I was trying to explain is that you can't rely just on big thrust for all the flight efficiency figures. Drag is a big driver and sloppy shaping of the vehicle carrying the engines can make the difference between two similarly configured airframes. 777 vs. A330.

 

BOEING will launch the 777X in the coming days, and this will kill the 747-8i which will soon join the A340-600 as another commercial failure.

 

The A340-500 was developed for a specific airline use. Extremely long range so that otherwise unobtainable routes could be flown non-stop. Thai Airways used these for Bangkok-JFK and Bangkok-LAX. Singapore Airways does SNG-LAX.

When this looked to be a good market Boeing came in with the 777-200LR. That killed any future Airbus orders because the Boeing went just a tad bit further and used less fuel to do it.

BUT the whole use of these aircraft failed. Information from a Thai Airways executive: So little cargo capability was left that their sales people did not try to make any significant sales. The pricing for LAX or JFK was less yield than the Bangkok-London.

It has been publicly quoted that the LAX run at 100% capacity still lost money.

Maybe the LAX-Singapore run does better because they do 100 pax all in business class but maybe it is only "less bad".

The A340-500 was based on a different assumption of world fuel pricing that turned out to be way wrong.

Going back to some earlier statement regard fuel savings be aware that there are an assortment of metrics used:

Fuel per seat mile
Trip fuel
Specific fuel Consumption

 

The 777 program from the start was run like a new airplane program should be run and subsequent prime production items were done IN HOUSE with SKILLED Boeing people. Quality control was strict and it was BOEING controlled. The engineering staff was the best that could be found and nothing was spared to achieve the best airplane possible by by good work ethic and cooperation with other disciplines. A critical examination would show that the program was conceived and conducted by AIRPLANE people not bean counters or whiz bang new age business wonks who saw "easy"and quick bucks as the goal instead of a good airplane.

 

A good illustration that shows that an airplane is a system of many elements that when all are carefully melded, the result is an efficient piece of machinery.

 

Also, BOEING used CATIA V3 (by Dassault Systèmes of France) to develop the 777. If memory serves me well, that was an industry first.

Boeing: Computing & Design/Build Processes Help Develop the 777

 

Correct. I was part of that transition when I was working on the 767 and 767X. When we were transferred to the 777 program it was all CATIA and by using it we cut years off the development time and improved the accuracy and quality of the design by being able to "run" everything on the computer and make changes on the fly.

 

Another article actually discusses that the -600 is very nose heavy, and as a result, burns more fuel trying to fly level. Airbus blames airlines for putting in 'fancy overweight' first/business class cabins as the driving factor. Airbus suggested airlines shift their cargo weights around, but in the end, as alluded to above with Thai, it just has to leave cargo behind.

 

That was the start of it, but not the sole reason. In the end, no twin at the time could carry the payload of the MD-11/DC-10 (or 747 for that matter). If one aircraft killed off the MD-11 (and put a serious hurt on the A340), it was the 777. It just took time, and further ETOPS extensions to do it. No one thought a twin with the capacity of the 777 would succeed the way it did.

Look at the derivatives afterwards: 767-400, 757-300, A340 series (failure for this line could be argued), those aircraft did not sell. And the 777-300ER is the aircraft that officially neutered the 747 line. I say neutered because the 747 is still selling (albeit not much these days). And you are correct in saying the 777X (well, 777-9 specifically) will be the final nail in the 747-8s coffin.

Boeing recently says it sees itself building the 747-8 and improving upon it for the next 20 years. Outside of a dedicated freighter with the nose door to which only old Soviet aircraft give it competition, I don't see it surviving that long as a passenger aircraft.

Twin is in, Four is dead.

 

Part of that was the use of an electronic mockup instead of the traditional metallic one. Boeing developed a program called EPIC (Electronic Pre-assembly Integration on CATIA) into which all of the 3D solids created by the designers were put, color-coded as to function, and that included all of the fluid lines and wiring bundles. They also created 3D humanoid figures to represent the mechanics and could pose them as needed to verify accessibility to do needed assembly, servicing or repairs. I understand that, because of this, the first 777 fit together on the first try much better than any prior number 1 Boeing airliner.

A related program called FlyThru allowed the user to literally "fly" through the EPIC structure, sort of a "fantastic voyage". This was all quite revolutionary in the early '90s; today it's standard procedure in the industry for new design.

CATIA evolved through Version 4 (used to design the F-22) and is now on Version 5, which was largely all-new and designed more to run on P.C.s rather than on stand-alone workstations as before. Version 6, an evolutionary development of V5, is beginning to enter service.

 

Jim, you are brining back all the stuff that we pioneered back in 1989-90. We accomplished a lot of " firsts" then; the first digital mock up, as you mentioned, the first digital definition of the loft, structure, mechanisms, wiring, tubing, inboard profile, kinematic studies of translating elements like the landing gear and flaps, and air flow studies over the entire airplane. We found area of turbulent air flow and supersonic flow where it wasn't wanted. My partner and I lofted three different nose lofts in two days that would have taken many many months in the old days, after running the air flow studies on them and finding shock waves in some areas. We used EPIC and Fly Through later on after much of the structures and systems were configured and we found many areas of conflict and interference. The Production Illustration Group Systems used Fly through when they were developing the plots to route the wiring and tubing. They developed their own little system and called it PIGS Fly. I was absolutely stunned when our group got together with the landing gear people and built in the computer the wheel well, complete landing gear with wheels and tires, inboard wing structure, all struts and retraction mechanisms, landing gear doors, and wheel mounted doors, and then not only went through the retraction sequence but rolled it over while in motion to look up into the wheel well to check for interferences. I could not contemplate the math that was going on at microsecond speed to accomplish what we were seeing. I have five framed " Certificates of Achievement" from that exercise. A personal letter from Alan Mullally, and one from VP Ron Ostrowsky. Of course, a few other guys got some too but at least we were recognized for making it look like we knew what we were doing. I was going through some stuff to throw out today and ran across a bunch of plots that I saved from all that but I think that I will keep some of them instead of throwing them away. One is a complete 3D assembly of the entire 777 , structures and systems that I helped to put together. I think that I'll keep it. I reread your post and should mention that tolerances were 00.00 on everything in the computer and all that data was translated to the loft lines, forming dies for skins, internal structures, and detail parts. When they produced some 747 parts using CATIA they couldn't fit them to the airplane that had been built to standard .03 manufacturing tolerances. A lot of interesting things have happened since I left and I still feel like it would be good to go back but...