Bernstein Research says ZA100 will be 8% overweight with a 10-15% shortfall in range.
Let's take a look at what that might mean for aircraft performance:
Boeing has confirmed that it is actively seeking to reduce the weight of the 787.
The airframer has never publicly disclosed the actual amount of weight it needs to remove from the aircraft, though ILFC Chief Steven Udvar-Hazy, who has been closely involved in the aircraft design as one of the 787's largest customers, says early aircraft will be overweight.
Airplane 20, which will be delivered to JAL, will be the first major production blockpoint incorporating significant empty weight savings and will see the max. takeoff weight grow to 227.9 tonnes.
According to documents dated April 2008 and obtained by rival Airbus, Boeing has already identified at least 1690 lbs of weight reduction for production aircraft, with up to 4000 lbs potentially available for elimination. If Boeing achieves an additional 4000 lb weight reduction, 787 performance would grow to just above 7,000 NM, per the PianoX assessment.
These weight overruns have the potential to be costly not only for ANA but for Boeing as well. For historical perspective, Boeing's contractual arrangements with United Airlines promised the US carrier up to $500 per pound above contractual weight per year, per aircraft for the 777 program in 1995.
Using the available data from PianoX, analyst and competitor assessments, 787 entry into service performance is tracked between 6,490 and 6,900 NM.
Without aerodynamic data and route proving trials that can only be gained in the upcoming flight test program, many of these range estimates fall within a reasonable, albeit speculative, analysis.
Yet, the contribution of technologies such as trailing edge variable camber, raked blended winglets, drooping ailerons and spoilers, laminar flow optimized engine nacelles and additional engine performance improvements all leave open questions until real-world data can deliver a conclusive verdict on aircraft performance.
Boeing plans to conduct a final weighing of Airplane Seven once final assembly is completed later this year.
BOEING COMMENT
Let's take a look at what that might mean for aircraft performance:
- Boeing targeted a Spec Operating Empty Weight of 252,500 lbs for a 787-8 and maximum empty weight of 191,000 lbs at firm configuration, according to the Airbus assessment. 8% over puts the weight between 15,280 and 20,200 lbs over target.
- The figure of 20,200 lbs correlates closely to the Airbus Dossier, which cites 21,050 lbs of LN1 maximum empty weight growth since firm configuration. Airbus cited Boeing documents in this estimate. LN1 would be significantly heavier as a result of the significant instrumentation and associated wiring installed for the flight test campaign.
- Using this data (15-20K lbs) against the 1% SFC shortfall in Trent 1000 Build 4A engines, the
PianoX performance analysis puts the 787-8 EIS range between 6,490 and 6,756 NM. (Up to 15% off of 7,650 NM)
- However, Bernstein estimates the performance of the 787 "will translate into a range near 6,900 nm., well below the promised 7,700-8,200 nm. range." (10% off off 7,700 NM and 15% off of 8,200 NM)
- Overall, using these various calculations, 787 range projections of overweight performance vary from 6,490 NM up to 6,900 NM.
- Great Circle Mapper comparison of 6,490 NM v. 6,900 NM v. 7,650 NM v 8,200 NM from Tokyo's Narita Airport for rough range performance of launch customer ANA's 787s.
Boeing has confirmed that it is actively seeking to reduce the weight of the 787.
The airframer has never publicly disclosed the actual amount of weight it needs to remove from the aircraft, though ILFC Chief Steven Udvar-Hazy, who has been closely involved in the aircraft design as one of the 787's largest customers, says early aircraft will be overweight.
Airplane 20, which will be delivered to JAL, will be the first major production blockpoint incorporating significant empty weight savings and will see the max. takeoff weight grow to 227.9 tonnes.
According to documents dated April 2008 and obtained by rival Airbus, Boeing has already identified at least 1690 lbs of weight reduction for production aircraft, with up to 4000 lbs potentially available for elimination. If Boeing achieves an additional 4000 lb weight reduction, 787 performance would grow to just above 7,000 NM, per the PianoX assessment.
These weight overruns have the potential to be costly not only for ANA but for Boeing as well. For historical perspective, Boeing's contractual arrangements with United Airlines promised the US carrier up to $500 per pound above contractual weight per year, per aircraft for the 777 program in 1995.
Using the available data from PianoX, analyst and competitor assessments, 787 entry into service performance is tracked between 6,490 and 6,900 NM.
Without aerodynamic data and route proving trials that can only be gained in the upcoming flight test program, many of these range estimates fall within a reasonable, albeit speculative, analysis.
Yet, the contribution of technologies such as trailing edge variable camber, raked blended winglets, drooping ailerons and spoilers, laminar flow optimized engine nacelles and additional engine performance improvements all leave open questions until real-world data can deliver a conclusive verdict on aircraft performance.
Boeing plans to conduct a final weighing of Airplane Seven once final assembly is completed later this year.
BOEING COMMENT
ATW - Boeing responds to skepticism, maintains 787 timeline - May 6, 2009
Regarding performance concerns, the company claimed the 787 will "meet mission payload commitments to all customers." However, it conceded that "early airplanes are heavy and [we] are working hard on implementing weight improvements."
Concerning the Bernstein report, it said, "the conclusion on range is inaccurate and the 787-8's range is closer to 8,000 nm. than 7,000 nm." Bernstein's report said it understood from customers and supplier discussions that the first production 787s are likely to be roughly 8% overweight, with range 10%-15% less than promised, which translated into a range near 6,900 nm., well below the promised 7,700-8,200 nm. range.
on May 6, 2009 1:51 AM | Reply
As I twitted for you (http://twitter.com/lvcivs/status/1711058467), the effect of range decrease can be really seen if you center at JFK: http://tr.im/kAqf
Cape Town, Johannesburg, Bombay, Calcuta, Hong Kong, Bangkok and others become out of range!
on May 6, 2009 2:57 AM | Reply
As I look at this figure of 15%, it reminds me of the whole point of this aircraft being such a "hit", namely the 15% savings in fuel. Now granted, a 15% shortfall in range does not mean a 15% increase in fuel costs. But I do find it interesting that the numbers seem to be indicating that Boeings "new technology" aircraft has some pretty old technology performance figures.
Granted that a weight savings program is in progress but there are a couple of points that need to be considered:
1. In previous programs, Boeing prided itself on getting the first aircraft's performance to match what they had forecasted. Any more than 2 or 3 % variation (on the plus or minus side) was considered to be a bad job of performance analysis. Based on that criteria, they have a "failure" here.
2. We are talking about a weight optimized aircraft, achieved through the use of composites to previously unseen levels in a large civil passenger aircraft. When one has an overweight aircraft, one typically saves a good portion of the weight by changing certain parts from metal to composites. OOPs! Can't do that here. There is now alot of weight to get out of an aircraft, where one of the major methods of weight reduction is no longer available.
I am curious to see if the A350 will also have this problem.
I personally think they charged ahead too quickly with this "all" composite structure without really considering/evaluating the implications of so little metallic structure vis a vis electrical bonding and lighting strike protection and are now paying for it. And Airbus is trundling down this same path. Time will tell if they have learned any lessons from the 787.
A shame that we will never find out in detail about how the weight was reduced. Assuming they do manage it.
Regards,
John
on May 6, 2009 3:27 AM | Reply
If I remember correctly, the 777 performed better than predicted once it started flying. What is the chance that the same will happen with 787?
on May 6, 2009 3:38 AM | Reply
A "bad" overweight for the 787-8 would be about 3%. If the overweight is actually 8% as mentioned by Jon then you can call it a disaster.
If the range shortfall is as much as stated by Jon (15%) then Boeing should consider redesigning the whole thing.
In my humble opinion, the 787-8 is not as bad as depicted. But I can be wrong.
See this related comment
http://www.flightglobal.com/blogs/flightblogger/2009/05/the-road-to-787-first-flight---9.html#comment-1575519
on May 6, 2009 9:34 AM | Reply
As your story evolves the most interesting part of what you are presenting is the cost of the airplane. How much has Boeing already spent to get weight out?
If we assume that $500 per pound in 1995 dollars holds, if my math is right, that means weight penalties of $10 million per year per airplane?
That has to be eating into the airplanes' profitability.
on May 6, 2009 11:04 AM | Reply
Thanks for the post Jon, I was really missing this kind of "let's put facts together" analysis over the 787 overweight problem. Everybody was so concern about the delay in the program that overweight was currently not in the media. (Trust me, solving overweight is ALWAYS present in our daily work at Everett)
As you pointed out, in this plane we do not have the recurrent solution in the industry of going to carbon to save weight, but we still have a handful of weight reduction opportunities (fortunately). The current structure is far from being completely optimized and we are working on it. And the same for the materials employed, I am sure we will see an improvement on they characteristics.
What is really shocking is the deviation in weight prediction, that issue should be analyzed internally to find out were was the problem. (I am pretty sure they are currently looking at that).
Thanks again for keeping us informed!
on May 6, 2009 11:28 AM | Reply
I think the above discussion is both interesting , but premature and speculative.
First, I would not trust a financial firm's analysis to be the basis of factuality. Also, the Airbus Dossier is a competitive and purposefully
damaging report. ( Look at whats happening to the A380)
There are no final weight figures to base a discussion on and there will not be until the test planes actually start flying. Plane #7 will produce the first meaningful weight.
It is also well known that the first twenty planes have been overengineered with many possibilities for reduction and change.
So, while dire predictions make for stimulating debate, it is worthless to consider this talk seriously Lastly, does anyone really think that Boeing was oblivious to this aspect from the very beginning of the planning process. The whole idea of using the composite material was for strength at a lower weight as well as production efficiences. They have had to correct the latter and are more than capable of reducing the former
on May 6, 2009 12:20 PM | Reply
How could someone from the aviation market, like Bernstain, put the numbers like 10%(!!!) + on the paper? It's totally unprofessional. If overweight margins would have been so huge, then what are designers and engineers there for? You can't just make something and then start looking for so huge difference in predicted and real product weight. I would say 3-5% is the margin of overweight on new designs.
on May 6, 2009 12:36 PM | Reply
Jon and how would Bernstein Research know what the weight of ZA001 is? How would Airbus even know? At best they are both making an educated wild guess. Since no one has ever built an aircraft like this, there is precedence for data. ZA001 is off course going to be over weight as it is the prototype aircraft. There is no surprise about that. What we really want to know is what will the 7th aircraft weight as this is going to be the first weight optimized aircraft and probably the first aircraft delivered to an airline. If I had to guess I would say the first six Boeing 787 test aircraft will eventually be spun off as VIP aircraft by Boeing Business Jets.
on May 6, 2009 1:59 PM | Reply
Truth is, Airplanes get -20% fuel savings flying obese Americans around the world. They gain +20% flying Asians around the world. Plane weight is not the problem. The obese are! If your ass is two seats wide, you should be charged for two airfares....
This plane represents the beginning of the learning curve. Carbon Fiber is the future. Small planes have been using this technology for years.
on May 6, 2009 2:00 PM | Reply
By the way, the maximum distance for the 777's just sold to Turkey is 7900 miles.
Both the Trent and GE engines should provide more thrust and power.
Just as a frame of reference
on May 6, 2009 3:04 PM | Reply
Bernstein Research needs to go back to guessing how many beans are in the Jar and Airbus needs to concentrate real hard on how it is going to build 14 A380 this year. Being relevant and envy are in play when comes to these two opinions. I hope we can cut and paste that analysis next to real numbers real soon.
on May 6, 2009 5:14 PM | Reply
Jon,
MEW is not maximum empty weight, but manufacturer empty weight.
The Airbus paper puts MWE at firm config at 95,5t, that's 210,500 lbs, not 191,000 lbs. 1 lbs = 0,4536 kg
You need to take into account that Airbus MWE is not the same as Boeing MEW. There are differences in weight accounting
You can't compare Airbus range figures with Boeing range figures or with PianoX range figures unless all are based on the same assumptions, i.e. use the same weights, mission profiles, winds, temperatures etc.
Likewise, you can't compare Boeing range figures from their website with range figures guaranteed to a customer, which contain all sorts of allowances and margins.
Just my two cents...