Talk:Boeing 787 Dreamliner/Archive 2

message: From article: "Winglets provide better efficiency over short distances while raked wingtips are superior over long distances"
Why wouldn't the longer wings be more efficient no matter what?  Do shorter flights spend more time at lower altitudes (higher density air), and thus don't need the longer wings?  An explanation would be helpful (as well as a citation).  -- thanx --68.35.43.82 02:48, 18 March 2007 (UTC)
replies: text: The effect of winglets and raked wingtips are different. Winglets are shaped in a way to use the wingtip vortices to produce thrust, while raked wingtips increase the effective aspect ratio. The reason short haul aircraft tend to use winglets more is that the extra thrust improves field performance and increases the rate of climb, which is a favorable trade to having less drag during cruise. On the long haul aircraft, cruise is the dominant mode of flight and thus the cruise drag dominates over the time to climb. Also, while it's not the case on the 787, in some cases the wingspan is limited by airport constraints and winglets offer a shorter wingspan including wingtip device than the raked wingtips (Though with the raked wingtips, the -8 and -9 have a 60m wingspan, which is one of the two major wingspan limits used by airports. The other is 80m, which the A380's 79.8m wingspan borders.) For more info, see Wingtip device. -Marimvibe 23:58, 19 March 2007 (UTC)
replies: text: Winglets do not produce thrust.69.22.218.109 23:40, 28 April 2007 (UTC)
replies: text: Yes, they do. They produce a forward lift vector, also known as thrust. ericg ✈ 04:26, 29 April 2007 (UTC)
replies: text: Please provide a high quality source. http://adg.stanford.edu/aa241/wingdesign/nonplanar.html says "Optimally-loaded winglets thus reduce induced drag by lowering the average downwash on the wing, not by providing a thrust component." 24.63.204.55 02:18, 1 May 2007 (UTC)
replies: text: But the full quote is: "The result that the sidewash on the winglet (in the Trefftz plane) is zero for minimum induced drag means that the self-induced drag of the winglet just cancels the winglet thrust associated with wing sidewash. Optimally-loaded winglets thus reduce induced drag by lowering the average downwash on the wing, not by providing a thrust component." By the paper's definition, the optimally loaded winglet is the one that produces the best L/D ratio. In contrast, field performance is largely dependant on T/W, and best climb performance is dependant on T/W - D/L, which may stand to benefit from winglets designed to maximize winglet thrust but make L/D slightly sub-optimum. Specifically, I recall a passage in a reference book (I think Encyclopedia of Modern U.S. Military Weapons, by Timothy Laur and a couple others, but I can't seem to find the book at the moment,) that calls out the use of winglets on the C-17 to be driven by the improvement in field performance. A good source would be helpful, but it should be from a designer and not an aerodynamicist in order to really examine why one solution is preferred over another in certain cases, but the aircraft design text I have hasn't changed much since 1985 as far as I can tell. Marimvibe 04:10, 1 May 2007 (UTC)

text: http://www.nasa.gov/centers/dryden/about/Organizations/Technology/Facts/TF-2004-15-DFRC.html says "Winglets, which are airfoils operating just like a sailboat tacking upwind, produce a forward thrust inside the circulation field of the vortices and reduce their strength." I'm pretty sure the Dryden Center knows what they're talking about. Maybe a little. ericg ✈ 00:19, 4 May 2007 (UTC)

text: As a person with some knowledge in this field I like to correct all of you. Raked Wingtips produce more lift than winglets. A 90 degree winglet produces no lift. It simply cancels out drag at the tips to improve efficiency. Thats all. Rakes wingtips produce a bit of lift. Also, as a plane travels down a runway, the outer parts of the wing start developing lift first and this continues towards the fuselage. Watch a 777-300ER go down a runway and you will see the tips pointing up rather quickly. Some winglets can produce a slight amount of lift, but not if they are pointing 90 degrees up. Simon--154.20.95.145 19:28, 3 May 2007 (UTC)
replies: text: These comments have no impact on the argument of comparitive efficiency. Marimvibe 23:15, 3 May 2007 (UTC)
thread_title:  Winglets and raked wingtips 

message: So where is the airplane acutally assembled and tested? —Preceding unsigned comment added by 219.108.16.189 (talk • contribs) 
* Everett, Washington in the Puget Sound area.  See About the 787 -Fnlayson 00:32, 29 March 2007 (UTC)
thread_title:  Assembly location? 

message: Why is there one date that needs a seperate format for clarification, when all others use the standard linked date and month and linked year? This goes against the norm for any article I've encountered, and goes against what the tutorial for linking date suggests. Marimvibe 00:57, 2 April 2007 (UTC)
replies: text: Gotcha. For some reason I didn't pick up the 7/8/7 significance. Marimvibe 01:36, 2 April 2007 (UTC)
replies: text: * Good deal.  I might mention the designation instead of (7/8/07), if there seems to be confusion with it. -Fnlayson 02:38, 2 April 2007 (UTC)
thread_title:  Date clarification in regards to roll out date 

message: In the last sentence of "Development" it states:
On March 19, 2007, BCA President Scott Carson and 787 program manager Mike Bair told reporters and investors that Boeing intends to roll out the first 787 on July 8, 2007
In "Technical concerns - Weight issues" it states:
The first six 787s built will be overweight according to Boeing Commercial Airplanes CEO Scott Carson, but the seventh is expected to be on target.
According to Boeing's Official Biography for Scott Carson: Scott Carson is executive vice president of The Boeing Company and president and chief executive officer of Boeing Commercial Airplanes.
I believe we should be consistent with Boeing's Official Biography, although it might be better to be consistent with the original news article's designation for Mr. Carson. Since Mr. Fnlayson is the primary editor for the Boeing 787 wiki page, I will leave it to his excellent judgement on how best to edit these two sections. --Dan Dassow 22:50, 7 April 2007 (UTC)
thread_title:  Consistent Reference for Scott Carson 

message: Is there any information regarding the number of orders that Boeing needed to breakeven on the 787 project?  I believe that the number was approximately 300 planes, which is well below the more than 500 orders the company has received so far.  I think it would be worth while to add this financial information in as it demonstrates the success of this plane and its importance to Boeing. —The preceding unsigned comment was added by Jaedglass (talk • contribs) 12:30, 25 April 2007 (UTC)
replies: text: I am sure Boeing's finance people have calculated the breakeven point where you recover your initial investment but they have not disclosed this number and I doubt that they ever will. Actual breakeven is a moving target. Various factors such as future inflation, contract revision with suppliers, and future labor cost will affect the outcome. Airbus is more sensitive to this number because once a project reaches breakeven, they have to start paying back the launch aid they had received. --Yasobara 21:23, 3 June 2007 (UTC)
thread_title:  Breakeven 

message: Please stop adding the biased info on the yoke vs. the sidestick controller. The sidestick may be a newer method of control inputting, but that does not make it more advanced by that fact alone. I am certian the sidestick controllers on early A320s are less advanced technologicially than the yoke systems in the 777. The 777 and 787 are FBW, so they do not use control cables physically connected to the yoke. That would be outdated, but simply using a yoke for electronic conrtrol inputs is not. - BillCJ 19:40, 9 May 2007 (UTC)
thread_title: Yoke vs. sidestick

message: There's currently 6 links to DesignNews.com, surely there should only be one that covers the 787. WP:EL. -- Rehnn83 Talk 07:42, 22 May 2007 (UTC)
replies: text: Those are six different articles. If there's one page that links to them all, then replace them with it. - BillCJ 08:00, 22 May 2007 (UTC)

text: Looking at the page history this links used to be in the references section - I think they (all 6 of them) would be better in their (or a footnotes section). -- Rehnn83 Talk 10:44, 22 May 2007 (UTC)
thread_title:  External Links to designnews.com 

message: I don't think it's mentioned in the article, but I took a tour of the Boeing plant at Paine Field and the tour guide said there would be a rollout ceramony on 7-8-07. —Preceding unsigned comment added by 24.20.179.3 (talk • contribs) 
* Thanks.  That's already in the article.  See the bottom of the development section. -Fnlayson 21:11, 2 June 2007 (UTC)
thread_title: Rollout

message: On what is the fuel efficiency claim based? On fuel per passenger per km/mile? And to which other airplanes is this compared to? The article does not cite any source for this. Themanwithoutapast 09:25, 25 April 2007 (UTC)
replies: text: Well, if you believe Virgin Atlantic, The 787 is 27% more fuel-efficient per passenger than the A340. But Boeing's "official" page on the 787 doesn't specify if it is per passenger or some other measure, just that it's 20% more fuel efficient than similarly sized aircraft.. --Bobblehead 18:18, 25 April 2007 (UTC)
replies: text:  The fuel efficiency is compared to the Boeing 767. The 787-8 is 20% more fuel efficient than the 767-300ER. And thats it. This was stated during the launch of the plane in 2004. The 787-8 is an exact successor to the 767-300ER. All other claims of efficiency over another plane are given during press conferences depending on what the airline is replacing the ordered planes with. Northwest during their press conference for the A330 said they would save 20% in fuel compared to the DC-10. The 787-9 is about 11% more fuel efficient than the A330-200. And on and on. I hope this helps.--Bangabalunga 01:38, 26 April 2007 (UTC)

text: Uh, from what you've said, that would applay to ALL airliners of a given size. THat means that other airliners would be even heavier than the 787 for a given passenger/fuel load for the same reasons, and thus the 787's efficiency would still be better than the traditional airliner. Granted, I'm not an aerospace engineer, but then, I'm not from England either with an interests in debunking Airbus's competitiors! - BillCJ 16:28, 9 July 2007 (UTC)

text: I was accusuing the Cambridge professor of an Airbus bias, no the user commenting about him. I don't have to know much about engineering to use the brain God gave me, and I can see that, based on what the user repeated, the engineering prof's comments seem very one-sided. As described, the factors would apply too ALL airliners of that range and size, thus the 787 would retain its advantages. As to throwing citation needed everywhere like a drunken sailor comment, please READ WP:ATTR. Contributors are required to source their material, no matter where it's from. Sure, anyone could probably Google any item on Wikipedia and find a source of some type for it, but it's not the reader's job to do that. That's the job of the contributor. Often, other editors will find sources for those items they did not add. Jeff (Fnlayson) often finds sources for tags that I've added, and for other editors, and I do that myself occasionally. It may seem liek madness sometime to keep adding tags liek that, but it's a necessary part of the process. - BillCJ 20:17, 9 July 2007 (UTC)
thread_title:  Fuel efficiency 

message: In scanning the page briefly all I see are mostly technical specs. 
Please add an "Innovations" section or something similar for layman who want a quick summary of that the big deal is. 
Thanks —Preceding unsigned comment added by 67.81.86.173 (talk • contribs) 
* Basically it's a lighter and thus more efficient design.  It uses mostly composites in its design to get there. Some of that is covered at the top (in Lead).  And there's already a Features section. -Fnlayson 02:43, 9 July 2007 (UTC)
replies: text: * The features section is a bit of a hodge-podge - it could probably be tidied up. Given the game changing nature of this aircraft, I think an section highlighting the specific innovations would be a good idea (as opposed to including them in with information about the cabin width and seating configurations etc). --Nick Moss 03:23, 9 July 2007 (UTC)
thread_title:  So What's so special about this plane ? 

message: I noticed that a couple of non-free images were deleted. BillCJ did the right thing when he removed them, however I think we have a bigger problem, the images he deleted I recognized as Boeing images... their status is exactly the same as some identified as free: 
Avianica 787  and Continental plus 787 image we're currently using in the infobox.
Boeing is pretty emphatic that aside from news organizations, which Wikipedia is not, the images are not free:
I'm going to remove them here, and then go over to the commons and have them removed. (The commons are for free media only, so somebody made a mistake over there.) Anynobody 06:12, 14 July 2007 (UTC)
thread_title:  Copyright violations 

message: Boeing plans to increase the air pressure and humidity inside the cabin of the 787. I'm unsure of the formula on this, but is there a significant weight penalty for increasing the mass of the air and humidity within the aircraft? ProhibitOnions (T) 07:08, 14 July 2007 (UTC)
replies: text: At 8000ft altitude (traditional), the density of air is .9805kg/m^3, at 6000ft (787,) .9091 kg/m^3, giving a .0714kg/m^3 difference.  Assuming the fuselage to be perfectly cylindrical, on the 787-9 there is a volume of 1132m^3, resulting in ~808 kg or 1778 lbs.  On top of that there will be some additional structural weight for the pressure vessel as well as increased weight as a result of the stronger structural components needed to deal with the other weight increases, and additional fuel weight. I wouldn't be surprised if weight at cruise is 2000-2500 lbs heavier than if the aircraft were designed for the traditional cabin pressurization. Marimvibe 12:00, 14 July 2007 (UTC)

text: * For delta density times volume, I get (0.0714 kg/m3)*1132m3 = 80.8 kg or 178.2 lb.  Rather minimumal really. -Fnlayson 17:07, 14 July 2007 (UTC)
replies: text: Going from 8000 feet pressure to 6000 feet pressure doesn't add 2500 pounds. Its not very significant. If it added 2500 pounds that equals the weight of 16 passengers which is too much for airlines to give up to make their passengers more comfortable.--Bangabalunga 19:13, 14 July 2007 (UTC)

text: *Right, adding something like 2000 lb wouldn't make much sense. -Fnlayson 19:40, 14 July 2007 (UTC)
thread_title: Higher cabin pressure and humidity: Added weight?

message: I've commented out the "number built" section of the infobox for now.  The plane which was rolled out does not even have all systems installed yet and has not operated on internal power.  Do we have any established conventions for describing the "number built" for an aircraft?  To me, the plane should at least be systems complete and possibly able to operate under its own power. --StuffOfInterest 13:30, 18 July 2007 (UTC)
thread_title:  Number built 

message: In Boeing_787#Features there are two points related to seating in the 787 requiring citations. I have not been able to find sources for this information other than blogs. The information appears to be correct based upon the Boeing fact sheets and cursory calculations, although there is an element of speculation in the text. Should we:
* Leave these bullets intact; 
* Cite the Boeing fact sheets;Boeing 787-3 Dreamliner Fact SheetBoeing 787-8 Dreamliner Fact Sheet Boeing 787-9 Dreamliner Fact Sheet
* Remove the citation needed tags; or
* Remove the bullets? 
--Dan Dassow 17:08, 18 July 2007 (UTC)
thread_title:  Seating 

message: ----
* I guess you mean the seat spacing bullets (items 4 & 5).  Also the cabin interior width and increase (item 6) is uncited too.  I say leave the fact tags on there for a month or so then remove if still unreferenced.  That's generally what's done with unsourced content with old fact tags. -Fnlayson 17:33, 18 July 2007 (UTC)
thread_title: Seating References

message: Stop editing that the first flight has been delayed to October until there is an official statement. Unconfirmed speculation, even in the mass media, is not a source. 192.88.212.44 19:40, 15 August 2007 (UTC)
thread_title:  First flight in October? 

message: The September 2, 2007 issue of the Chicago Tribune has an article that might be relevant, "Boeing coining plan for composite parts: Greater use of superstrengthened plastics in the 787 raises concerns about detecting damage -- now done using a quarter -- but company says visual inspections will be enough" By Julie Johnsson. http://www.chicagotribune.com/business/chi-sun_fiber_0902sep02,0,6108705.story?page=1 I am not sure how this article might be used. --Dan Dassow 01:31, 3 September 2007 (UTC)
thread_title:  Repair of Composites 

message: What is the estimated runway length for this plane...will it be able to use airports like LaGuardia with short (6000 ft) runways?  —Preceding unsigned comment added by 68.14.84.60 (talk) 03:28, 9 September 2007 (UTC)
replies: text: Yes it can use 6000 feet runways specially the 787-3 and La Guardia has runways that are longer than 7000 feet by the way. American is looking at buying 30 of these to fly out of La Guardia.--154.20.78.130 20:22, 11 September 2007 (UTC)
replies: text: American insists on using ERJ135 and ERJ145 at LGA worsening the congestion.  AA wanted the DC-10 to be able to use LGA.  Archtransit 17:49, 17 October 2007 (UTC)
thread_title:  Takeoff Roll? 

message: BTW, I added a number of new photos, including some compositions I added with the use of free-use flickr or commons photos.  Any opinions?  I hope they helped give the article some visual benefit.  Some pics for the lower sections of the article would help if anyone has them. Enigma3542002 04:01, 4 October 2007 (UTC)
thread_title: New photos

message: Is this still a technical concern? Mikedz 19:53, 19 October 2007 (UTC)
thread_title:  Engine interchangeability 

message: This is a nitpick on English style. The phrase "most unique" should not be used.
From: Hypertext Guide to English Grammar, Mechanics, and Usage Rules
http://ei.cs.vt.edu/~cs5014/courseNotes/5.TechnicalCommunication/tc_2_Usage.html
Do not use an adverb with an adjective that cannot be qualified. 
Wrong: most unique, absolutely essential, quite impossible 
Correct: unique, essential, impossible
The following sentence in Boeing_787#787-3
"Boeing sees the 787 family as a game changer with this variant as the most unique of the three."
should probably be changed to
"Boeing sees the 787 family as a game changer with this as the unique variant of the three."
I did not see this problem with grammar until user:BillCJ reverted a change by user:67.167.166.218 on 17:13, November 10, 2007.
I am suggesting this change rather than making it, since I am not certain the revision captures the intent of the original sentence. I also do not wish to cause problems for user:BillCJ who is one of the guiding spirits of this article (Boeing 787) and Wikipedia:WikiProject Aviation.
Sincerely,
--Dan Dassow 23:28, 10 November 2007 (UTC)
replies: text: THnaks for the benifit of the doubt. I did check my old college English grammar book (Little, Borwn), and you are, of course, correct. THat's a tid-bit of Grammar that I meesed adding to my editing/grammar knowledge. I get in the habit of reverting IP edits made without edit summaries, as they are generally indistinguishable from vandalism. Sorry for the mistake on my part, and the lack of good faith extended to the IP. I hope he explains his edits next time, as I would have checkd my grammar book first with an adequate explanation. - BillCJ 23:39, 10 November 2007 (UTC)
replies: text: BillCJ, I probably would not have noticed this little grammartical error if I had not had it pointed out to me by a very good technical writer. Although the change by user:67.167.166.218 makes the sentence grammatical, it does not quite sound right.--Dan Dassow 02:05, 11 November 2007 (UTC)

text: The useage you cite is correct "formal" English right now, and that is what Wikipeida uses, so no further arguments from me on that point. However, it may be another of those "formally" correct usages that goes by the wayside, as the current incorrect usage is very common, and most people (myself included) don't even know it's incorrect. I think using modifiers with the "absolute" words is very useful, and does serve a purpose. To me, it's a case of the language evolving past the rigid grammar rules, many of which didn't come from English originally. It's quite possible (is "quite" allowed here?) that the useage even predates the imposition of this grammar rule, as with the continued useage of double negatives in English, despite all the efforts of mathemeticians to stamp them out! :) - BillCJ 03:04, 11 November 2007 (UTC)
thread_title:  "most unique" - nitpick on English Style