Wikipedia:Featured article candidates/CFM International CFM56/archive1


 * The following is an archived discussion of a featured article nomination. Please do not modify it. Subsequent comments should be made on the article's talk page or in Wikipedia talk:Featured article candidates. No further edits should be made to this page.

The article was promoted by Karanacs 01:29, 30 June 2010.

CFM International CFM56

 * Nominator(s): SidewinderX (talk) 19:04, 19 May 2010 (UTC)

I am nominating this for featured article because I think article meets the criteria and is among the best aircraft engine articles on Wikipedia. The engine has a rather interesting history, and it is one of the most numerous engines in service today. It has passed both a peer review and an Aviation wikiproject A-class review. As the main contributor, I've tried to strike a suitable balance between technical content and usefulness to the average reader, however as someone who works in the industry I may not be the best judge of that. I will try and be particularly responsive to comments with respect to the technical detail in the article for that reason. Thanks! SidewinderX (talk) 19:04, 19 May 2010 (UTC)
 * Comment—no dab links, no dead external links. Ucucha 19:12, 19 May 2010 (UTC)


 * Comments
 * It may be worth noting that unlike Douglas with the DC-8-70, Boeing didn't actually sell any CFM powered civil 707s, either new or as re-engined aircraft.
 * Ok, I've added a line and a ref to the 707 part about not selling any and Boeing suspending the program in 1980. -SidewinderX (talk) 11:49, 20 May 2010 (UTC)
 * The article mentions use in the E-6 in the KC-137 section - should the CFM powered E-3 Sentries for France, UK and Saudi be mentioned here as well?
 * I have mentioned the E-3 now in that section. -SidewinderX (talk) 11:49, 20 May 2010 (UTC)
 * I seem to have a vague recollection that the problem that caused the Kegworth crash was specific to the more powerful engine for the 737-400. It may be worth checking to see if this was the case.
 * I don't recall that, but if you find something let me know and I can incorporate it! -SidewinderX (talk) 11:49, 20 May 2010 (UTC)
 * htis (already cited) states it was the CFM 56-3C for the 737-400 that was grounded as does this, while this article from Flight gives some idea why the fault was missed.Nigel Ish (talk) 18:24, 20 May 2010 (UTC)
 * I clarified which subvariants were affected, and added a line about having to replace fan blades in 1800+ already-delievered engines. Does that seems to cover the details enough, or is there more you'd like to see? Thanks! -SidewinderX (talk) 18:50, 20 May 2010 (UTC)
 * None of the comments are show stoppers. Otherwise a good, detailed article.Nigel Ish (talk) 21:59, 19 May 2010 (UTC)
 * Thanks for your comments! Let me know if there's anything else I need to do to address these concerns, or if you spot something else. Thanks! -SidewinderX (talk) 11:49, 20 May 2010 (UTC)
 * - Support- Yes its fine now. Nigel Ish (talk) 16:13, 21 May 2010 (UTC)


 * Comments
 * 1) ""CFM56 Selected for KC-135 Re-engining". Aviation Week and Space Technology, 28 Jan 1980." Page number missing
 * 2) Aviation Week and Space Technology is officially Aviation Week & Space Technology, as used ref 12.
 * 3) In references where articles of Aviation Week & Space Technology are used, author name and publisher is missing. It would help if Issue no., vol no. are added too.
 * 4) Is a separate "Applications" list really necessary? The applications are already given in "Variants"
 * 5) Also, add Applications in "CFM56-2 series" table, like the other ones.
 * 6) Why "Specifications (CFM56-7B18)" for one machine needed?
 * 7) I really liked the way the article explains jargon in "Notes". Can jargon like Thrust, Bypass Ratio, Pressure Ratio, Dry Weight be explained too? Also link them in first table.
 * 8) Why isn't Thrust-to-weight ratio (recorded in Specifications section) recorded for all engines in respective tables?
 * 9) All images have good licences. Very well illustrated article-- Redtigerxyz  Talk 11:02, 20 May 2010 (UTC)

Replies to Redtigerxyz

1) Done!

2) Done!

3) Many of the articles do not have an author name (I believe a lot of the news stories are jointly written and compiled by the staff). I have the author name for articles that list it. As for publisher, I didn't realize it was common practice to include a publisher for magazine articles... I think I mostly followed the examples here, but if the consensus is to add publisher, I can do that. As for issue and volume... I think, as a weekly publication, AW&ST does not have issue and volume numbers, but when I get home I can look at some of my physical copes to see if they're there.
 * To follow up, I have checked my physical AW&ST issues, and they do not have issue or volume dates. -SidewinderX (talk) 14:35, 26 May 2010 (UTC)

4) The "Applications" section is a standard section for WP:Aircraft and WP:AETF. I like it because it allows readers to use the ToC to jump to the applications if that's all they're interested in.
 * Then covert it into prose (may be a para would be enough), maybe with an image. -- Redtigerxyz Talk 05:50, 21 May 2010 (UTC)
 * The standard practice for the Aero-engine task force is to leave that applications section as a list, as mentioned in this guideline. Most of those applications are explained in prose form in either the history or the variants section. Thanks! -SidewinderX (talk) 12:13, 21 May 2010 (UTC)

5) Done!

6) The specs section is another one of the standard project/task force sections. In that table there are a lot of the standard performance and configuration numbers that one can use to easily compare engines. It's been the consensus just to use one variant for that detailed table, and mention the other variants in the article. This engine has a lot of different variants, and the company's website does a nice job of listing them all, so that's why I included the less-detailed comparision tables in the specific variant section.
 * I am not an expert. Will buy this argument. -- Redtigerxyz Talk 05:50, 21 May 2010 (UTC)

7) I've wikilinked "Thrust", "Bypass Ratio", and "Pressure Ratio" in the first table, and then added a note for dry weight, including a wikilink to the automobile focused dry weight article.
 * For a non-expert, it is very difficult to understand these terms. So to save a non-expert some clicks on wiki-links, I suggest form a notes sections below "CFM56-2 series" table, explaining the table parameters as in "Notes" section. That would really help. -- Redtigerxyz Talk 05:50, 21 May 2010 (UTC)
 * I don't mean to seem obtuse here, but is there something specifically about that table that you think needs more explanation, rather than the terms themselves? Those terms are used many times earlier in the article as well. Do you think they need to be explained earlier on, or does it seem more appropriate to explain them in the table? -SidewinderX (talk) 12:04, 21 May 2010 (UTC)
 * For a non-expert, otherwise, they are just some jargon terms, a short explanation either in the table or at first occurrence of term like thrust, would be nice. -- Redtigerxyz Talk 16:36, 25 May 2010 (UTC)
 * A link should suffice for these terms; a definition would disrupt the flow of the prose.--Sturmvogel 66 (talk) 12:48, 26 May 2010 (UTC)
 * As a point of comparison, another aero-engine featured article, the Rolls-Royce Merlin article, does not explain terms like "horsepower", "supercharged", and "crankshaft" in the prose. These terms are wikilinked for those who don't already know them. -SidewinderX (talk) 14:34, 26 May 2010 (UTC)

8) That was a choice. I didn't want to overload those tables with too much data (and there's a lot there already). As for T/W ratio specifically... many of the sub-variants of each type actually have the same weight, so the change in thrust is as useful as a measure as the change in T/W. (Although I know some of the subvariants vary in weight as well).
 * I am not an expert. Someone who is an expert needs to check. -- Redtigerxyz Talk 05:50, 21 May 2010 (UTC)
 * Hmm, I guess my answer kind of missed your question. So the idea behind the tables was to highlight some of the differences between the subvariants in each class of variants. The main difference is the amount of thrust the engine produces. Some of the engines are different weights, and that's why I included weight as well. Bypass Ratio and Pressure ratio were included because those parameters are often the ones that are responsible for the change in thrust. For example, if the "-A1" subvariant produces 1000 pounds of thrust, and the "-A2" produces 1300 pounds of thrust, the reader can look over in the table and see that the "-A2" has a higher pressure ratio as a way of explaining why the thrust is higher. There are absolutely more specifications that could have been included on those tables, but at some point you're just adding numbers for numbers sake. I tried to pull some of the most valuable characteristics into the table, and only those. Does that explain my reasoning any better, or am I still missing the point? Thanks! -SidewinderX (talk) 12:04, 21 May 2010 (UTC)
 * I got your point, but I can not really comment if the most important facets are used for comparison, so I suggested some expert needs to check that, but as someone who works in the industry, you may the best judge of what needs to put or what can be ignored. Will trust you on this issue and assume the important facets are covered in the table comparison. -- Redtigerxyz Talk 12:14, 21 May 2010 (UTC)

Ok, I think I've at least commented on all of your concerns. Take a look and let me know what you think! -SidewinderX (talk) 13:18, 20 May 2010 (UTC)
 * CFM56-5 series para 1 needs a ref for facts not covered ahead like "The Airbus designator for aircraft equipped with CFM engines is "1"."
 * Hmm, that was something that I left in there from an earlier editor... It's consistant with Airbus, but the source in that article looks like the aerospace version of Yahoo! Answers, so I wouldn't call it a reliable source. If you agree that that's not a reliable source, I will just go ahead and remove that sentence from the article. -SidewinderX (talk) 11:40, 21 May 2010 (UTC)
 * Wikipedia articles can not be considered WP:RS, so using Airbus directly is out of question. Yahoo! Answers is not a Rs either. Search Airbus official site, it may have something. -- Redtigerxyz Talk 11:58, 21 May 2010 (UTC)
 * I could find anything reliable on the web or in any of my other sources, so I just removed the comment. Thanks! -SidewinderX (talk) 19:10, 21 May 2010 (UTC)

-- Redtigerxyz Talk 05:50, 21 May 2010 (UTC)
 * Comments 7, 8 are just suggestions. The article can be a FA without them too. The only reason I have not supported the article is because I have not found enough time to go through it entirely, but the parts I have read are good, so I have not opposed it also. -- Redtigerxyz Talk 15:57, 28 May 2010 (UTC)


 * Support. Nice work. - The Bushranger Return fire Flank speed 13:24, 21 May 2010 (UTC)
 * Support. Fine job here. -Fnlayson (talk) 14:40, 21 May 2010 (UTC)

Sources issues
 * There is a real concern about the number of citations to pages from CFM International's own website. While some of these give purely technical information others, such as 2, 27 and 34, are press releases of a somewhat self-congratulatory tone; likewise, 31 and 40 (among others) have a promotional feel. Broadly, the company should be treated as a primary source; while it may be a reliable source for factual information, claims that go beyond technical data, dates etc should be verified by independent third party sources.
 * I understand your concern about the citations to CFM's own pages, but I think those sources were used, in almost every case, for their numbers. Although most of the press releases do have promotional tones (that's a core function of a press release), they also have valuable content and specifications that aren't available elsewhere. And sometimes, when it is available elsewhere, it is a simple regurgitation of the press release. As for the specific mentions...
 * 2 was used a source for how many engines had been delivered. The other item it was listed for had a technical error in it (re-used ref name). That has now been fixed ("adding" another ref to the list, I will try and account for that in my following comments).
 * 27 (now #28) was used as a reference for what the goals of the Tech Insertion package was, and what componenets were changed. I don't believe this type of information is any less reliable because it comes from the company itself.
 * 31 (now #32) was used as a reference for the reduction in number of fan blades. Again, a number thing.
 * 34 (now #35) was used as a reference for the dates in which the double annular combustor first started development and first entered service. I don't believe that the fact this is a press release makes those dates any less reliable.
 * 40 (now #41) was used as a reference for the number of in-flight shut downs per flight hour, and in the text of the wikipedia article, it is written as "CFM International states..." so as not to sound like an independent claim.

I hope that addresses at least the concerns you had with the mentioned sources... if there are other's that you'd like me to explain, please list them and I can do so. Thanks! -SidewinderX (talk) 18:47, 21 May 2010 (UTC)
 * OK. This seems reasonable, but I will leave it to knowledegeable editors to decide if there is an issue here. Brianboulton (talk) 18:56, 22 May 2010 (UTC)


 * Minor format issues
 * Refs 1 and 15: both of these are to conference papers, but the formats are slightly different (e.g. dates for the first, not for the second). Formats should be consistent.
 * Added dates for #15. -SidewinderX (talk) 18:17, 21 May 2010 (UTC)


 * Ref 2: in all other cases you have used the form "Retrieved: (date)" Here you use "Accessed: (date)"
 * Fixed! -SidewinderX (talk) 18:17, 21 May 2010 (UTC)


 * Ref 23: publisher is The Boeing Company
 * Fixed! -SidewinderX (talk) 18:17, 21 May 2010 (UTC)


 * Ref 25: Aviation Week's Show News Online is not a print journal and should not be italicised.
 * Done! -SidewinderX (talk) 18:17, 21 May 2010 (UTC)


 * Ref 29: Aviation Week need italics
 * In this case, this was an online article for Aviation Week, so to be consistant with your above request, I left it without italics. -SidewinderX (talk) 18:17, 21 May 2010 (UTC)


 * Ref 33: Italics
 * Likewise, this is an online article, not a print article. -SidewinderX (talk) 18:17, 21 May 2010 (UTC)

Otherwise, sources look OK Brianboulton (talk) 15:30, 21 May 2010 (UTC)


 * Comments. I was involved in the A-class review for this article and it might have been felt that I was uncharitable not to change my comments to a support, I felt that it needed more work at that stage. I tend towards the stricter side of reviewing standard (and expect the same treatment from reviewers looking at any article I might have nominated), aiming for a very high quality article which is what we nearly have here. I have gone through myself just now, reviewing and copy editing which was useful. As these are comments it is up to the nominator whether to act on them, I do think that this article is almost at FA level.
 * CFM International gets abbreviated to CFMI and then goes back to CFM International about halfway through.
 * I guess my thought process, although probably not 100% consistant, was to use the full name the first time it appeared in a paragraph/section, and then to use the abbreviation if it was used again after that. My day to day work lives in a world of acronyms, so I guess I try to not overdo it on my own! -SidewinderX (talk) 19:04, 21 May 2010 (UTC)
 * Overlinking in the 'Variants' section, almost every instance of aircraft type in the tables is wikilinked to the same article.
 * I can't remember where I read this (it's not in WP:Table), but I was under the impression that tables should be able to "stand on their own" in some sense, although I'm not sure it that should apply to each row. I will say my personal preference is to leave them wikilinked in the table... having them as links fits in with my view of tables as sources of data. If these consensus is to de-link them, however, I will do so! -SidewinderX (talk) 19:04, 21 May 2010 (UTC)
 * Refer to WP:REPEATLINK and the last bullet in the Repeated links section for that. -Fnlayson (talk) 19:27, 21 May 2010 (UTC)
 * My understanding of that guideline is for sortable tables where lines may end up a fair distance apart and need to be linked in each instance, the tables here are not sortable (yet!). Nimbus (Cumulus nimbus floats by)   20:09, 21 May 2010 (UTC)
 * I hadn't thought about making the tables sortable before... but that could potentially be useful (sort by bypass ratio, thrust, pressure ratio). I'm not a table guru, but would it be easy to make them sortable? -SidewinderX (talk) 21:50, 21 May 2010 (UTC)
 * Ok, I have gone ahead and made the tables sortable by all the columns expect model and applications (i.e., all the number columns are sortable). I like having them sortable now, and does this suitable address the overlinking concern in the variants section? -SidewinderX (talk) 22:43, 23 May 2010 (UTC)
 * It is worth checking the Airbus aircraft type links as there are lots of redirects (maybe these articles have been renamed recently?).
 * I believe you ran through them and made some corrections... would you still like me to run through them? -SidewinderX (talk) 22:55, 23 May 2010 (UTC)
 * There may be some editor's POV or conjecture, not biased but phrases like In what was likely the most important early purchase.. sounds like opinion unless it is supported by the cited reference, I don't have it to check.
 * I see what you mean here. I personally like the prose aspect that it brings to the article (after all, this is in the history section), but do you think something like "In what was an important early purchase" would be a better fit for the article? -SidewinderX (talk) 19:04, 21 May 2010 (UTC)
 * Personally I would leave it out completely as it could be considered a phrase to avoid unless the author of the reference stated that it was an important purchase. What I tried to achieve in the Merlin and R engine articles was to present the bare facts and let the reader decide, without knowingly making any assumptions. I know that it is not easy to make the text interesting (even gripping!). Nimbus (Cumulus nimbus floats by)   20:32, 21 May 2010 (UTC)
 * Ok, I have re-read the prose there and realized that removing that phrase doesn't do any harm, so I have gone ahead and removed it. Thanks! -SidewinderX (talk) 14:41, 26 May 2010 (UTC)
 * An impression I got was that the text could be usefully shortened/clarified by removing extra words, lots of 'as well as', 'some' and 'alsos' and other words that could be 'padding it out' unintentionally. There are some technical explanations of gas turbine components that are covered by a wikilink near to them, it's a judgement call whether these are needed. I could do this myself if it is felt that it is necessary although I am working for the next three days. Less is more is what I am trying to say!!

Hope my points are valid, cheers Nimbus (Cumulus nimbus floats by)   18:40, 21 May 2010 (UTC)
 * Just spotted that cite number 3 is available as a PDF from the Flight International archive: - 1414.html if the link is included then everyone can check the facts, have not added this to the ref tag as I know that ref formatting is in progress. Nimbus (Cumulus nimbus floats by)   19:57, 21 May 2010 (UTC)
 * My link is not working (a problem that happens with the dash and spaces on Flight) if you cut and paste the code you should get the article, getting a bit weary, sorry! Nimbus (Cumulus nimbus floats by)   20:03, 21 May 2010 (UTC)
 * Whole unformatted link: http://www.flightglobal.com/pdfarchive/view/1999/1999%20-%201414.html to the reference PDF. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   21:32, 21 May 2010 (UTC)
 * I believe you mean ref #4. Yeah, the whole thing in on the website, but I couldn't figure out a good way to link it... it's a 30 page story about the CFM56, and the way the Flight does their archives has each page as a separate pdf file. I couldn't figure out a good way to link the whole article online. I decided the best thing to do would be cite the whole thing as it originally was, a print story. If you have a suggestion on how to do it better, I'm all ears! -SidewinderX (talk) 21:47, 21 May 2010 (UTC)
 * Sorry crossed eyes, 3 is close to 4! Well, I usually link directly to the page that the fact is on, readers can navigate the article from the thumbnails on the side bar. This was how my tamed copy editor formatted a similar reference in the R article: Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)    21:58, 21 May 2010 (UTC)
 * Hmm... I just feel like that would add a lot of clutter to the references section (turning 1 source into 10 sources). On the other hand, it's clearly valuable to the reader to be able to find the source online... what if the ref was cited something like this, would this be a reasonable compromise?--
 * Norris, Guy (1999). The CFM56 Story. Flight International. 19 - 25 May 1999. Available online at flightglobal.com archive from: p. 1387 to p. 1419 of 1999 archive. Retrieved: 23 May 2010.
 * Another way is to treat the article as a book and simply cite the author, date and page numbers, this was done in the Merlin article, the Flight articles are listed in a 'Bibliography' section. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   18:51, 24 May 2010 (UTC)
 * Ok, I've kinda combined the ideas that were floating out there. It's all in one ref, but I've added a weblink for any reader interested in reading it. I also realized that the proper name for the story was "CFM56: Engine of Change" and not "The CFM56 Story", so I have made that correction as well. How does that look to you? -SidewinderX (talk) 00:36, 25 May 2010 (UTC)

(Undent) I don't understand this line: It soon became clear that Boeing and Airbus were not going to build all new aircraft, can you clarify it? Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   09:20, 27 May 2010 (UTC)


 * A couple more questions if I may (in the aim of improving the article, vice pickiness!)
 * How is the engine started? I assume it is air start from an auxiliary power unit? A curious reader might also wonder how you turn a jet engine off, not sure if that would class as excessive detail in this article.
 * It does start with an APU, but I don't have really have any sources to explain (and cite) the starting process very well. Furthermore, there's a wide range of APUs that it works with (at least three different ones on different 737s!), so I wouldn't really want to write much about it without a couple of good sources. -SidewinderX (talk) 12:40, 28 May 2010 (UTC)
 * Is it possible to simply say ...is started using compressed air from an auxiliary power unit? Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   16:41, 28 May 2010 (UTC)
 * Well, the other wrinkle is that I'm *pretty sure* you can start it with compressed air from a ground start cart. When you start getting into this you really start talking about aircraft operation and not just the jet engine... I'm looking for a decent source so I can add the line you suggested in there (I don't want to claim anything without a citation at this point), but I haven't found much so far. -SidewinderX (talk) 03:34, 1 June 2010 (UTC)
 * This excellent (though rather old) Flight article: http://www.flightglobal.com/pdfarchive/view/1981/1981%20-%201100.html gives a clear technical description and indicates both air and electric starting for the Dash 2 variant at least, I don't think it has been used yet in the article. The drawings, particularly of the engine modules, could be used as external links as I think they have encyclopaedic value to help explain the technicalities. The reason that I am asking these questions is that my understanding of a Featured Article is that it should effectively carry two levels of detail, a basic overview for readers who know little about the subject and a more in depth level that exhausts virtually all the available sources for the curious, difficult to achieve sometimes. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   07:57, 1 June 2010 (UTC)
 * Great article find! I've added a couple little details to the article using that Flight article... thanks! I also added a cutaway to the external links section, but I used the one from Flight's website, not from within the article. I didn't get a good chance to read through the article, but I only saw a mention of provisions for an electric starter. If you there is more detail there (and a mention of air start), feel free to add a line to the design section intro! (I used ref name="cfm56age") for that article. -SidewinderX (talk) 10:51, 1 June 2010 (UTC)
 * Plenty there if ever it was needed. I deduced that it has an air starter as an 'Air-start supply pipe' is labelled as item 19 on page 1122, I am paid to spot very small things in my day job! I shall probably leave you in peace now, good luck. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   11:11, 1 June 2010 (UTC)
 * I've spent a bit more time looking for a good source for how the engine starts, but there just isn't much out there, particularly in the way of reliable sources. Unless this is a major sticking point, I think I'd like to leave this until later (when a suitable source will reveal itself ;) )-SidewinderX (talk) 13:24, 3 June 2010 (UTC)
 * Does it feature a thrust reversal system? If so, how does it work?
 * I have add a brief description of thrust reversers to the article. I didn't want to get too technical, so hopefully what I've added is useful. I did find that great photo on commons, so I think that helps. -SidewinderX (talk) 12:40, 28 May 2010 (UTC)
 * Is 'booster' a term limited to CFM International use? Just seems confusing to refer to booster/low-pressure compressor alternately. I've not come across the term in my own experience of inspecting low and high pressure compressors of Rolls-Royce turbojets and turbofans. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   09:53, 27 May 2010 (UTC)
 * It's not limited to CFMI, but I'm usually more comfortable with low pressure compressor as well. However CFMI tends to use "booster" more often (for example), so that is what usually made it into to text.-SidewinderX (talk) 16:40, 27 May 2010 (UTC)


 * Image review


 * File:CFM56 P1220759.jpg - Editor's own image - Commons, correctly tagged.
 * File:Nixon-Pompidou.JPG - Commons - US PD-Gov.
 * File:KC135-CFM56.jpg - Commons - Licensed as US PD-Gov but attributed to Boeing?
 * The applicable terms an conditions are available here. "Generally speaking, nothing on this site is copyright (Defense Department imagery and unclassified information is usually deemed to be in the public domain) but if in doubt you agree to examine the Rights datafield for appropriate information." There is no details in the copyright field of the meta data, so it should be in the public domain. It was likely taken by a Boeing photographer in Boeing's chase plane for the US Air Force, and the Air Force released it to the public domain. -SidewinderX (talk) 11:11, 25 May 2010 (UTC)
 * On another page there they state this: Information presented on DefenseImagery.mil is considered public information and may be distributed or copied unless otherwise specified. Use of appropriate byline/photo/image credits is requested. So it's probably fine, just struck me as odd at first sight as PD Gov images are usually credited to government employees. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   12:09, 25 May 2010 (UTC)


 * File:Boeing 737-400 Engine.JPG - Editor's own image - Commons, correctly tagged.
 * File:CFM56 dsc04641.jpg - Editor's own image - Commons, missing standard description and source template.
 * File:Cfm56-3-turbofan.jpeg - Editor's own image - Commons, missing standard description and source template.
 * File:Astraeus.commons.b737-300.g-stra.arp.2.jpg - Editor's own image - Commons, missing standard description and source template. Missing metadata, probably an older upload by Adrian Pingstone, a prolific contributor of his own airliner images.
 * File:DSCF6247a.jpg - Editor's own image - Not on Commons (but could be transferred), missing standard description and source template.
 * File:Easyjet thrust reversers arp.jpg - Editor's own image - Commons, missing standard description and source template. Just reviewing this image for completeness as it has been added since my original review. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   21:26, 5 June 2010 (UTC)

The licensing of the KC-135 image needs to be confirmed. The infobox image is a rear view of the engine (which always looks slightly strange to me for engine articles!) there is a front view available but it faces to the right (away from the text). Alt text also present but this requirement appears to be in a state of flux. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   08:46, 25 May 2010 (UTC)
 * A quick review of the "CFM56 Category on Commons shows several other candidates for the infobox image, File:CFM56 dsc04643.jpg, File:CFM56-5C Mockup Cutaway.jpg, File:Turbofan-Engine.jpg, and File:CFM56 dsc04642.jpg. I chose the one that is in the infobox because I felt that it was the clearest, most detailed photo of the bare engine available. I don't like File:CFM56-5C Mockup Cutaway.jpg and File:CFM56 dsc04642.jpg because they are bad photos (blurry, not clear). I'd prefer not to use File:Turbofan-Engine.jpg because it focuses on the front fan, and there is a better photo later in the article showing the front fan. The only other option would be File:CFM56 dsc04643.jpg, which gives a nice profile view of the engine, but I think the existing image is a better quality photo. Let me know what you think! Thanks. -SidewinderX (talk) 11:11, 25 May 2010 (UTC)
 * It was a comment on the quality, noting that a better lead image is not currently available (and proving that we looked for one!). There has been some discussion recently at WT:FAC regarding image reviews, mainly that the licensing gets checked but the quality was not necessarily reviewed. I've done both here and would say that the Featured Article image criteria (3) has been met (although I stand to be corrected by more experienced image reviewers!!). Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   12:09, 25 May 2010 (UTC)

Support--Sturmvogel 66 (talk) 12:48, 26 May 2010 (UTC)

6/3/2010 Summary To summarize where this FAC currently is...

There are 4 Supports (User:Nigel Ish, User:The Bushranger, User:Fnlayson, and User:Sturmvogel 66).

There are also 4 Comments. I believe most of them have non-critical issues outstanding (e.g., would like a second opinion, or just had a suggestion that I couldn't easily incorporate.)
 * I don't know who entered the above unsigned summary, but this FAC needs more independent review. Sandy Georgia  (Talk) 15:30, 4 June 2010 (UTC)
 * Opps, that was me, forgot to sign! Ok, I welcome any other reviewers who are willing to take a look at the article! -SidewinderX (talk) 17:47, 4 June 2010 (UTC)
 * make that 5 supports. I did not know that there was so much to write about engines.  A very good article. Suomi Finland 2009 (talk) 19:56, 5 June 2010 (UTC)


 * Oppose
 * After giving the article a brief glance, I'm going to oppose based on prose. I'm concerned about the tone of some statements in the article; "despite enduring a difficult and politically charged beginning, is now one of the most prolific engine types in the world with more than 20,000 built", is one of many statements that seems unnecessarily adulatory. Asking questions of the reader (" GE was now faced with a dilemma—should they build two 10-ton engines, one with "limited" technology with SNECMA and one with "advanced" technology on their own, or should they try to develop a single, advanced, engine?") is another no-no. There are comma splices in the lead ("Although the CFM56 is a reliable engine, several fan blade failures were experienced during its early service, one failure was noted as a cause of the Kegworth air disaster"), repetitious phrasing and clauses (one section ends with " GE decided to apply for an export license for the F101 core technology", and the next section begins with "In 1972, GE applied for an export license for its F101 core technology"), and groupings that do not qualify as paragraphs (you need at least three sentences). Subsections are disassociated from their parent sections and feel like lists more than integrated parts of the article.
 * Contrary to the image review above, I think that most of the images linked need much clearer claims of ownership and status, preferably by using Information. Der Wohltemperierte Fuchs ( talk ) 18:00, 9 June 2010 (UTC)
 * Hi David -- Thanks for reading through the article and leaving comments. If there are more specific areas than those you listed, I request that you list them as well so I may properly address them. As for your specific comments--
 * "despite enduring..." - The goal of that sentence is to illustrate that, after facing political and customer demand challenges that brought the program to within two weeks of being suspended, it became one of the most widely used gas turbine engines in the world. If there are specific words in there that bother you, let me know and I'll consider changes, but I don't think words like "endure", "difficult, and "politically charged" are non-neutral or unnecessary. -SidewinderX (talk) 19:55, 9 June 2010 (UTC)
 * Asking questions of the reader... - This is my first FAC, and I haven't commited the MoS to memory yet, so if there is a specific violation there, point it out to me so I can learn for the future. If you're questioning the content of that sentence, that phrasing is adapted from the source, and I tried to keep the intent of source intact. If you would like to read the source (it's a newspaper article), drop a line on my talk page and I can e-mail or copy/paste the relevant sections from it. -SidewinderX (talk) 19:55, 9 June 2010 (UTC)
 * Comma splices... I have tweaked that line to use active tense and make more sense. Let me know if there is still a concern. -SidewinderX (talk) 19:55, 9 June 2010 (UTC)
 * Repitious phrasing... Could you be more specific about your concern with the specific example you pulled? Between those two sections is a level 3 heading, and I wrote the section below it with the assumption that a reader might have jumped directly there from the ToC. Additionally, those two sections have different focuses (the birth of the engine in the first section and export issues in the second), so I believe that the repition helps the reader transition from one thought to another. -SidewinderX (talk) 19:55, 9 June 2010 (UTC)
 * Can you be specific about which groupings you don't think qualify as paragraphs? I learned that the defining characteristic of a paragraph was that its content differed from what preceeded it, not the number of sentences. If there are sections that you think are too "list-like", please point them out to me so I can try and tie them together with prose. -SidewinderX (talk) 19:55, 9 June 2010 (UTC)
 * Images. Can you please be more specific about which photos you think need more status information? -SidewinderX (talk) 19:55, 9 June 2010 (UTC)
 * Thanks again for reading through the article. I will look forward to seeing your responses! -SidewinderX (talk) 19:55, 9 June 2010 (UTC)
 * No part of an article should repeat itself aside from the lead. Repeating information between sections suggests that the content of those sections needs to be refined. As to paragraphs, in academic writing, paragraphs generally need at least three sentences: the topic, supporting, and concluding sentences. Shorter paragraphs almost always show that the idea is either not important enough to be discussed separately or that it is lacking more information. As to images: File:KC135-CFM56.jpg is improperly attributed to a US employee and is most likely a copyvio. Der Wohltemperierte Fuchs ( talk ) 20:57, 9 June 2010 (UTC)
 * I can clarify on the images. Where I stated missing standard description these are the images missing the Information template that David highlighted, I think that there are five or so. The KC-135 image was discussed and appears to be good but something 'hit me'as not being quite right. As I said I am not an image reviewer but I did my best. Awadewit is very versed in image reviews, I would ask her nicely if she could have a look at these. During one FAC I had problems dealing with an image uploader who would not assist with image licensing, the solution was to use either my own images or correctly licensed ones. The moral is that it is easy to get 'suckered in' to thinking that every image on Commons is correctly licensed, not so and something I learned the hard way. Cheers Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   22:49, 9 June 2010 (UTC)
 * Ok, as that image has now been questioned twice, I've gone ahead and replaced it with the photo that is clearly a USAF photo. Let me know if there are any issues with it! -SidewinderX (talk) 23:46, 9 June 2010 (UTC)


 * I have adjusted the wording in the "applied for an export license" sentence... let me know if you're still concerned with it and I'll look at it again. As for the paragraphs... I'll work my way through the article and see what I can do, but if you could point out specific areas of concern it would be easier for me to address them. Thanks, -SidewinderX (talk) 23:46, 9 June 2010 (UTC)


 * On prose: I think I described the text as 'clunky' in a much earlier version of this article (I can't find the diff, perhaps it was during the A-class review), I commented on it again above as still having extra words. It is possible (and appears from your questioning of David's comments) that you can not see any problems with the text. I repeat my offer that I am very willing to run through the article and modify the text and implement other improvements to better fit the Wikipedia guidelines. All passion has to be removed. I am no Shakespeare but I do understand fairly well what is required here, your personal style or preference might be undetectable afterwards but the article should be even closer to FA standard. It may be that it has to be 'archived' to be fixed to everyone's satisfaction (not mine), it's not the end of the world if this happens (see Boeing 777 FA history). I could spend a few hours on it tomorrow, aware that this has been reviewed for getting on for a month now. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   00:30, 10 June 2010 (UTC)
 * If you're willing to go through it, and you have some time, feel free! I guess I'm not expressing how I feel best in these comments here; it's not that I don't see any problems (I just went through part of the article after my early comments), it's just that I can better work on areas that specifically called out. I wrote most of this article, so obviously I had some reasoning behind my writing choices, but I don't mean to seem standoff-ish! Just having the specific areas pointed out make it easier for me work on them. -SidewinderX (talk) 01:23, 10 June 2010 (UTC)
 * I expect a very special barnstar if the article is promoted this time round ;-)! I will work on it tomorrow as promised. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   01:33, 10 June 2010 (UTC)
 * I have spent a fair while this morning working on the article in what I hope are improvements and I sincerely hope that I have not introduced any errors or changed any meanings, I only got down as far as the bottom of 'Development'. I have added a clarify tag to the line about Boeing and Airbus not building new aircraft that I mentioned above, I do not understand this at all. I also made Villaroche a redlink, we are given a wikilink for the GE location in the lead but not SNECMA. Featured articles can have red links as far as I am aware. Something that I only just noticed is the order of the upper sections. The 'Tech 56' section in development contains technical content that has not been covered yet or introduced, this is in the 'Design' section lower down.
 * I have attempted to clarify the "no new aircraft" section, if you think it still needs clarification, re-tag it and I'll expand more. -SidewinderX (talk) 12:47, 10 June 2010 (UTC)


 * It would be better in my view to rearrange the sections, adding a new first section of 'History' or 'Background' to contain the need for the engine, politics, and CFM International formation etc. I would follow this with 'Design' (explaining how it works) then 'Development' (focussing on technical aspects only). I admit that I wrote the guidelines for aircraft engine articles about 18 months ago where I suggested a combined heading of 'Design and development' but I took care to make sure that these were accepted by the task force by discussing them on the task force talk page. The text could be rearranged but first instances of wikilinks, abbreviations (spelt out in full) and any refname formatted cites would be in the wrong order. I have e-mailed a very good copy editor and asked him to run through the article as I am no expert on grammar and punctuation. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   12:32, 10 June 2010 (UTC)
 * I see your point about the article order. I think we can rename the Development level two as "History", rename the Early Development level 3 as "Development" (level 2). In general, I like the idea of development before design, get the history and whatnot out of the way first, but you're right in that the Tech56 kinda screws that up. On the solution side, I think I can rewrite that section in a historical/development context, while moving the technical details down to the design section. If that sounds like a good plan I can do that after you finish your copy edit. Just let me know. -SidewinderX (talk) 12:47, 10 June 2010 (UTC)
 * Whatever works best, Featured article criteria 2b is the criteria concerning this. I know that we have discussed our different understanding of the word 'development' previously. In my line of work (Research and development) we research something (test it) and then develop it (make it better). The 'Development' section in aircraft articles will overlap with the history as technical improvements are also chronological milestones, the tricky part is clearly separating the two subjects (history and technical improvements) or combining them in a logical way. Thanks for addressing my 'clarify' tag, makes much more sense now. Nimbus <font style="color:#2F4F4F;">(Cumulus <font style="color:#708090;">nimbus <font style="color:#D3D3D3;">floats by)   13:24, 10 June 2010 (UTC)
 * Ok, I've tried to pull some of the component-specific stuff out of the Tech56 section and move it down to the "design" section, does it read more smoothly now? -SidewinderX (talk) 17:16, 10 June 2010 (UTC)

break

Two editors (other than myself), have now completed fairly thorough copy edits of the article, hopefully addressing many of your concerns. I would appreciate it if you could take a look and point out anything you still think needs addressing. Thanks! -SidewinderX (talk) 12:16, 14 June 2010 (UTC)
 * I contacted User:David Fuchs on June 14th to ask him to review the most recent updates to the article and see if we can turn his opposition into a support or comments, but he has not commented yet. I will note that his talk page states that he may not be around much the summer. -SidewinderX (talk) 10:45, 16 June 2010 (UTC)
 * Sorry it took so long for me to get back to you. On looking at the article again... I'm going to sustain my oppose. In the lead, there's still improper usage of commas and semicolons; in the body, awkward phrasing, missing non-breaking spaces, et al. I'd like to help edit, but I don't have time on-wiki right now for much beyond vandal-fighting. Der Wohltemperierte Fuchs ( talk ) 20:52, 18 June 2010 (UTC)
 * Hi David -- Thanks for taking another look. I'm sorry to read that you still see some problems with the article. I just ran through and tried to grab a few things in the lead, but your comments mention more than that. I'll try and run through it look for the missing non-breaking spaces... that's a problem I thought I had already licked! I know you said you're busy, but I would be easier for me to try and fix the issues if there are more specific areas you could point out. Thanks -SidewinderX (talk) 01:22, 19 June 2010 (UTC)
 * Just go through the article with a fine tooth comb. First look at all the commas and semicolons.  Then look for all the non-breaking spaces.  Finally read each sentence and see if it is awkward.  Would a teenager not interested in engines understand it.  After that, you're done!  The article should be considered as pass after that.  I have personally fixed one criticism of Der Wohltemperierte Fuchs being the comma usage in the lead.  SidewinderX fixed the non-breaking spaces.  Both of us has worked on the phrasing. Suomi Finland 2009 (talk) 20:24, 19 June 2010 (UTC)
 * The prose still isn't there in my opinion, but I'm tired of being hassled over this, so I'll just strike and do more interesting things with my time. Der Wohltemperierte Fuchs ( talk ) 13:54, 25 June 2010 (UTC)


 * Support. There are a few minor rough edges, but overall I believe this meets the FA criteria. Malleus Fatuorum 18:31, 25 June 2010 (UTC)


 * WP:NBSP check needed, and I'm finding some undefined (unlinked) terms like lbf (and others). Sandy Georgia  (Talk) 02:38, 26 June 2010 (UTC)
 * I've gone through again checking for non-breaking spaces, and fixed a few more. Let me know if there are any others you see.
 * I clarified lbf and kN in the lead (they were already wikilinked in spelled-out form, just not in short form).
 * I updated the captions per your edit note.
 * With respect to "why are note terms bolded"... The notes are definitions/examples of certain terms that aren't well defined on Wikipedia (at least in the sense the article uses them in). My motive was to use the notes as mini-articles/definitions, wherein the term being defined was the topic and therefore bolded. The point is to make clear what each note defines or describes, and bolding the terms does that well. I welcome a differing opinion if you have one, but it seems to me that the notes application falls in the cracks of the MoS.
 * -SidewinderX (talk) 06:14, 26 June 2010 (UTC)
 * I'd like to hear from others on the bolding issue, but shouldn't they be redlinked if they aren't defined on Wiki? Also, you didn't get the WP:MOS quite right-- only full sentences get full stops (sentence fragments don't).  Sandy Georgia  (Talk) 11:56, 26 June 2010 (UTC)
 * You asked to hear from others. The bolding issue doesn't seem like an issue to promote or kill an article, in my opinion.  The very most important criteria for a FA has been met, in my opinion. Suomi Finland 2009 (talk) 16:42, 26 June 2010 (UTC)
 * I believe someone has gone after me to check the captions issue, let me know if it needs another look. As for redlinks to the terms... it's an interesting idea. Some of the terms, like "Chevron", could feasibly have articles. As there is already a Chevron page (disamb page that doesn't have an aviation link on it), would it be worthwhile making a redlink to something like Chevron (aerospace)? Likewise, would it be worth making a link to Shroud (turbine) or something (there already is Shroud (disambiguation))? Mixed and unmixed exhaust flow *could* be linked to Bypass duct, but that stub has nothing in it about the terms actually being defined and I figured that would confuse the reader rather than help. Engine trim is really just a contextual term, not anything worthy of an article. Low pressure shaft is also just a definition, not an article topic. (Although a better Jet engine article would probably have it defined there). For what it's worth... -SidewinderX (talk) 01:14, 27 June 2010 (UTC)
 * It strikes me that using Notes to define terms that deserve Wiki articles is ... anti-Wiki :) The notes shouldn't be Notes at all, rather wikilinks.  Sandy Georgia  (Talk) 02:21, 27 June 2010 (UTC)
 * Haha, fair enough. I've added redlinks to chevron and shroud, as well as wikilinks for mixed/unmixed exhaust. I'll stand by my comments that engine trim and low pressure shaft just need definitions... I've never messed with Wikitonary, but maybe I could just copy my note into Wikitonary? I'm not sure what the citation requirement is for Wikitonary... As for dry weight... In the note I have a wikilink to Dry weight (automobile), but I think it would be confusing if I listed that link in the article... should I make that a redlink to Dry weight (aviation)? -SidewinderX (talk) 03:35, 27 June 2010 (UTC)
 * To be fair, another reviewer was asking for a notes section to define terms rather than (or in addtion to wikilinks.Nigel Ish (talk) 08:24, 27 June 2010 (UTC)
 * The above discussion is preserved as an archive. Please do not modify it. No further edits should be made to this page.