Talk:Minimum control speeds

That second paragraph in the lede
Seriously, wtf. Either that was written by someone who thought they were actually writing a primary source textbook, or it's been ripped off wholesale from one without credit. Either way, it's biased, and written in too informal a manner. I'd fix it or just nix it right now, but the problem is, given what it says, whether doing so would be to further mislead readers as to the impartiality (and/or reliability) of the rest of it unless the entire article was to be re-written.

Quite how it managed a "B-grade" with that in place is beyond me.

Remind me, how do we flag it with one of those natty full-width top-of-the-page banners, again? 193.63.174.211 (talk) 14:02, 19 March 2014 (UTC)


 * NB, yes I've seen the note given within the HTML comment block at the top of the page. Whilst the sentiment of it is noble, and the rules are there to be broken, I still feel it's maybe in violation of the main WP tenets. Any pilot who decides to use the information listed here as the basis of their knowledge concerning safe control speeds, instead of a more professional source, probably shouldn't be entrusted with command of an aircraft in the first place; you wouldn't want drivers of road vehicles to do similar instead of seeking professional instruction...


 * This should be a place for collecting independently verifiable information - with it standing and falling on its own merit, rather than the prejudices either of editors who were taught it differently (and, in the writer of that comment block's opinion, "wrongly"), or the firebrand retort of whoever wrote that part, who believes those editors to be in the wrong, appealing to our emotions in order to drive their personal point home. Either a plane can be safely controlled at a particular speed when its critical engine(s) has/have failed, or it can't. Presumably said editor has done a study we can review? 193.63.174.211 (talk) 14:11, 19 March 2014 (UTC)


 * *scans rest of article* ... wow, someone's got an axe to grind, haven't they? The image with the caption "This placard would remind pilots"... is that your own work? Or is it something that's being officially mooted as a future required fitment by the FAA or similar? Because if it's the former... sorry chum. WP:FORUM, WP:SOAP, WP:NOTTEXTBOOK. C'mon. Keep it factual and encyclopaedic. If this issue has got your back up so much, write a book about it. Fill it full of juicy scandal about notorious crashes that could have been prevented. Cause public outcry and hit the bestseller list. THEN reference it here. Rather than burying your campaign on a WP page that a few thousand people might ever read at best. 193.63.174.211 (talk) 14:21, 19 March 2014 (UTC)




 * Did I mention how the revision history suggests this article is 99.8% the work of a single guy who dropped it into WP as a fait accompli, and it hasn't seen any other significant attention for nearly 6 whole months since? Dear oh dear. 193.63.174.211 (talk) 16:58, 19 March 2014 (UTC)




 * Right, did some copyediting, got bored, have now gone and found relevant banners. However, in the spirit of not wanting to compromise your life saving, paradigm shifting mission too much, these may help:


 * [WP:OTHER]
 * [Creating Controvertial Content]


 * OK? 193.63.174.211 (talk) 15:59, 19 March 2014 (UTC)

Found templates, about eight that would apply in fact, picked the most relevant four, had some fun with the CoatRack one, gave up and kludged it the best I can (it's just intrinsically broken and ironically under-documented, far as I can tell), washed hands. Done and done. 193.63.174.211 (talk) 16:54, 19 March 2014 (UTC)

Re to talker 193.63.174.211:
The 'someone' who wrote this article is a top aircraft expert, a graduate of the USAF Test Pilot School (class 1985A), for which the entry level was a MSc degree in engineering or a BSc degree and an entry exam. Test Pilot Schools were founded in Western countries after World War 2 because too many accidents happened during flight-testing new airplanes by 'regular' pilots who thought they knew all about airplanes.

The article was written because during the past 50 years incorrect definitions of minimum control speeds appeared in most books, including on WP. Authors of aviation books, flight manuals, articles on WP, etc. just copied their texts from incorrect sources, resulting in more than 3,000 casualties during the past 25 years (only counting the ones reported on the Internet). Even manuals by the FAA do neither agree with the airplane design methods taught at aeronautical universities, nor with their own flight test techniques presented in the FAA Flight Test Guides (AC 23-8 and AC 25-7) and not with flight-test techniques taught at Test Pilot Schools either.

The article was written using Airplane Design books of Dr. Jan Roskam, University of Kansas, course books of three Test Pilots Schools in the USA and UK and personal flight-test experience of the author. All of this is of the highest available level. Please review the references presented in the article before commenting any further.

The article will definitely save many lives of pilots and their passengers, provided pilots read and understand it; it will be found, eventually. May be the article is written in too informal a manner, but is definitely not biased; it might be better understood this way. The article is believed to be accessible and understandable for as many (pilot-)readers as possible; the accident rate might reduce. Regret you didn't like it, talker 193.63.174.211, hope you learned from it though. There was no reason for the language you used. Fly safely.

Harry FTEof85A (talk) 10:50, 2 April 2014 (UTC)

Reverting edits, please start a discussion
I have made some edits, that removes content that simply refers to a volume or regulations. I would like to edit this document further to make it concise and properly referenced.88.105.35.149 (talk) 22:51, 30 March 2017 (UTC)


 * There's nothing wrong with citing regulations, indeed, in this sort of topic the regulations are very important. However, I agree that some sections are entirely unreferenced and should be removed to improve the article's concision. However, discuss here BEFORE removing the content - I have added it back for now, because you removed a lot of references that created errors in the cut-down version.  Quasar G  t - c 18:47, 30 March 2017 (UTC)


 * However the regulations cited are the entire volume of regulations, so it is somewhat meaningless, There is a lot of factual information in the page, but also a lot of option that is simply referenced as a volume of regulations. I will start my edits again, one by one, and attempt to provided specific references, not just a 1000pages... The edits can then be disussed but please do not revert my entire effort!!!! thankyou88.105.35.149 (talk) 22:51, 30 March 2017 (UTC)


 * Actually, the reference cites a specific section of the regulations (Part 23 and Part 25, § 149), so please do not remove any material that is relevant and supported by this reference. Also remember to sign your edits by typing four tildes ( ~ )  Quasar G  t - c 18:57, 30 March 2017 (UTC)


 * Ok I can see he has referenced § 149 but that is not the basis for an entire article. In other words many of the points made are not referenced properly at all! Anyway please allow me make my edits and discuss them individually instead of just making me start again! Junmping in and simply reverting someone work without some justification is not appropriate.88.105.35.149 (talk) 22:51, 30 March 2017 (UTC)


 * I agree that nobody should blind revert, and that is not what I was doing. I suggest you propose an edit here, then it can be discussed before the edit is made. By the way, thanks for taking an interest in Wikipediaa and discussing this with civility, rather than edit warring. IPs like you are, unfortunately, rare.  Quasar G  t - c 19:07, 30 March 2017 (UTC)


 * IP: One, unexplained edits may be indistinguishable from vandalism, especially when large amounts of content are removed. Two, the only edit summary in your first edit was "Concise summary", which is meaningless when you removed such a large amount of content, along with the automatic Tag: "references removed". I reverted on that basis, as I'm sure the other editor did also. Quasar has mentioned the references issues, and concur those are problematic. - BilCat (talk) 19:24, 30 March 2017 (UTC)


 * BilCat, yes but the sequence was... I made a good faith edit, with an explanation. Arjayay just reverted it with no explanation... I put it back, you then reverted it again simply citing Arjayay as your the reason for your edit... I made further good faith edits with explanations. Quasar just jumps in reverts the lot... I propose to make my edits again, keeping in mind the considerations raised here. If there are issues with my edits please start a discussion on this page. Thankyou for your consideration — Preceding unsigned comment added by 88.105.35.149 (talk) 20:35, 30 March 2017 (UTC)
 * You need to take 's advice here, and propose your changes on the talk page before going live on the article. Additionally, you need to sign your talk page comments. You were reverted in this case for a significant loss of valuable information, multiple grammatical mistakes, and lack of clarity.  Propose your changes here, so they can be discussed prior to publication.  Scr ★ pIron IV 21:57, 30 March 2017 (UTC)


 * I did take Quasar advice I made a single edit, I made sure not to loose any references. As far as discussing it first here. No one has made any such attempt before on this article as the page shows. I made a small moderate edit as way forward. 88.105.35.149 (talk) 22:52, 30 March 2017 (UTC)

88.105.35.149, : I'm currently attempting to rewrite the article at User: Quasar G./Minimum control speeds. At the moment, the main issues are that the article goes into way too much detail and often goes off on tangents, and much of it is copied from the paper the IP mentioned. Feel free to continue making suggestions here.  Quasar G  t - c 18:59, 31 March 2017 (UTC)

Original Research or Opinion regarding how these definitions are portrayed in other publications
This article tries to portray how Vmc is explained in other publications an idea expressed by Harry Horlings, perhaps the original author or source — Preceding unsigned comment added by 88.105.35.149 (talk) 22:11, 30 March 2017 (UTC)

Removal of Cleanup Banner
I believe this article needs work, I started a number of edits in good faith. I put a cleanup banner to invite other to contribute, it was not defamatory. ScrapIronIV has deleted this with out establishing any consensus I would like to put back to invite others to contribute. Is there any reason that an editor should not be able to put this request out there?


 * The banner is content was 'This article while containing much factual information, is also an opinion piece written or sourced from one author. It could do with some work'.88.105.35.149 (talk) 23:13, 30 March 2017 (UTC)
 * The reasoning has been clearly communicated on my talk page and in the edit summary. Would you care to explain how this technical article on aviation and flight characteristics is an "opinion piece"? Also, you really need to start signing your posts.  Scr ★ pIron IV 22:51, 30 March 2017 (UTC)


 * Firstly the article contains a lot of factual and useful information, as stated in the banner though that information is not very well sourced. i.e. vague references to large complex documents on a complex technical issue (That is a separate issue). However in many places in this article it expresses a view on how this definition is portrayed in many publications, this is a view or opinion held by Harry Horlings, a likely author or source of large part of this content. That view or opinion is not necessarily supported by other people and in any case no references for that view are provided. Finally I don't believe it is appropriate in this case to remove a banner that is not offensive or makes any bold claim, without some consensus.88.105.35.149 (talk) 23:04, 30 March 2017 (UTC)


 * Actually, adding the banner was a Bold move, which was Reverted and is now being Discussed. Please read WP:BRD - Consensus is required to keep any material boldly added to the page. Please provide some proof of your claim that a) The author of the content is the aforementioned Harry Horlings, b) That his definition is opinion (remember that this is not fringe science, and c) that the definition is not supported by mainstream aviation science.  Scr ★ pIron IV 23:32, 30 March 2017 (UTC)

OK, I will expand on my original point.

Firstly the article contains a lot of factual and useful information, however that information is not very well sourced. i.e. vague references to large complex documents on a complex technical issue. It either references certification standards in FAR23.149/25.149 or the EASA equivalent, (that's fine), or there are large swathes of text providing a physical explanation of the scenario but with ZERO references for that explanation.

On your questions please provide proof a) The author of the content is the aforementioned Harry Horlings, I have no wish to. I have no issue with the content actually being primarily from Harry Horlings, he is no doubt a smart guy, thought there are a few clues in the history (the first few edits of article) and in this talk page... As I said much of the content is factual and accurate but poorly sourced, in my opinion. The issue with regard to opinion is that the article expresses a view on how this topic (which is basically a definition of a particular set of circumstances) is expressed in aviation literature, and how that definition is understood and used by both pilots and other technical actors. This view or commentary is not referenced and is original research or an opinion, and not something that a layperson might appreciate.

In other words it takes a view on the mainstream view, and the 'view on the view' IS original research, original versions of this article went much further...

Following are some snippets that highlight this last issue:


 * 1) Many manuals for pilots and reports by accident investigators present and use VMCs as they are defined in aviation regulations that are for design and certification of multi-engine airplanes, such as FAR 23 or FAR 25 or equivalent[1][2] and not as they apply to the operational use of the airplanes by pilots. Therefore, this article intends to bridge the knowledge gap ...
 * 2) Therefore most test pilot schools teach to
 * 3) The VMC(A) definition for use by pilots is therefore different from the VMC(A) definition for tail design engineers and for certification, and could be:
 * 4) As explained, pilots do not need to know about these factors
 * 5) This definition is correct for tail design engineers and for certification but is often inappropriately copied into pilot manuals, because it contains elements that are neither appropriate, nor applicable to operational pilots.
 * 6) For airplane design engineers: 	For pilots: (where is the definition for a wiki reader) :-)
 * 1) As explained, pilots do not need to know about these factors
 * 2) This definition is correct for tail design engineers and for certification but is often inappropriately copied into pilot manuals, because it contains elements that are neither appropriate, nor applicable to operational pilots.
 * 3) For airplane design engineers: 	For pilots: (where is the definition for a wiki reader) :-)
 * 1) For airplane design engineers: 	For pilots: (where is the definition for a wiki reader) :-)
 * 1) For airplane design engineers: 	For pilots: (where is the definition for a wiki reader) :-)

In summary I would like to put the banner back, perhaps with a more definitive or appropriate description. I would also like to make some good faith edits to the text as time permits, hopefully other will assist me in the spirit of WP:BRD by not reverting my edits completely, but start a discussion88.105.35.149 (talk) 00:46, 31 March 2017 (UTC)

Much Improved Article!
Quasar G, Has made a much improved edit to this article that has addressed the issues raised in the banner. i.e. 'an Opinion piece'

There are still some issues remaining, which I will raise here, before make an edit.

1. In the summary it says 'they are often used by accident investigators to determine whether the pilot was following aviation regulations such as FAR 23 and FAR 25.[6][7]'

This is not correct or at least misleading, nor supported by any reference is the article. They are limits, established by a prescribed method, they are NEVER targets for pilots, perhaps for a designer they may be a target...

2 the summary that says it applies to 'wing-mounted engines' is misleading. Vmca applies to any engine inoperative that creates an asymmetry where aircraft control becomes and issue.

88.105.42.54 (talk) 09:59, 1 April 2017 (UTC)


 * I agree with both of those points: make the edits as you see fit.  Quasar G  t - c 10:23, 1 April 2017 (UTC)


 * I will give some thought and make the edits to the summary, I think the summary needs to be a little bit more generic, being specific is difficult without being wrong. My thoughts are also to move the 1 Regulations and variants section towards the bottom of the article, and use the rest which is mainly correct but still poorly referenced on the details, as the natural expansion of the summary, so the reader understands at least what VMC is generally. Then the regulation sections can tackle some of the minutiae.88.105.42.54 (talk) 12:30, 1 April 2017 (UTC)


 * I moved the Regulations and variants section (now renamed) a little further down in the article, and renamed the engine malfunction to Physical Description. I think the structure is a little bit more balanced, still many errors or important details without citation, but will tackle some of those shortly. Will try to add some citations as I go.88.105.42.54 (talk) 14:48, 1 April 2017 (UTC)

Summary or Opening paragraph
the two sentences

'VMCs only apply if at least one engine is still running at maximum (takeoff) setting, and are included in the aircraft flight manual of all multi-engine aircraft. VMCs are also used by aircraft design engineers for sizing the vertical tail and flight control surfaces of aircraft.'

has the following problems,


 * 1) the first sentence is incorrect,
 * 2) no citation for any of it.
 * 3) last sentence is a bit of of stretch and no citation
 * 4) the concept of multiple VMC speeds has not been introduced.

Is it necessary for me to run every change line by line through this talk page? Should I give up now? Please also be respectful of my efforts!88.105.45.225 (talk) 23:06, 1 April 2017 (UTC)


 * Is the first sentence is incorrect? The whole point of VMC is that there is an imbalance of forces, which requires at least one engine to be operative. See WP:CITELEAD for information on citations. Since the information in the lead is repeated in the article itself with sources, it is not necessary to cite sources in the lead. The fourth point you made is important, I will add a sentence just beforehand explaining the existence of multiple VMCs.  Quasar G  [[user talk:Quasar G.|

t ]]- c 23:14, 1 April 2017 (UTC)


 * Is the first sentence is incorrect? YES. and there are other ways to get the point across, one way might be to state it 'requires an imbalance of forces created by an operating engine.'


 * I get that citations may not be needed in the summary, but the second paragraph is a stretch for summary, and space could be used better88.105.45.225 (talk) 23:27, 1 April 2017 (UTC)


 * Can you explain exactly how the first sentence is incorrect? It certainly fits with the rest of the article at the moment.  Quasar G  t - c 23:31, 1 April 2017 (UTC)
 * Max take off power only applies to VMCa and VMCg, it does not apply to VMCl, that is before getting into the issue of de-rated power. plus the rest of the article needs work. I was simply trying to create a concise and yet reasonably accurate and informative summary.

88.105.45.225 (talk) 23:50, 1 April 2017 (UTC)


 * I wouldn't worry about the lede being concise; we have a reasonably long article here, warranting a reasonably long lede. If it was more than 15 lines long, it'd need cutting down, but at the moment it's ok.  Quasar G   t - c 23:56, 1 April 2017 (UTC)


 * I reverted your edit back, too the following: I noticed you did not discuss your changes, care to explain ;-) ?


 * 'The VMC only applies if at least one engine is still running at maximum (takeoff) setting, and is included in the aircraft flight manual of all multi-engine aircraft. VMCs are also used by aircraft design engineers for sizing the vertical tail and flight control surfaces of aircraft.'


 * Ironically, take off power is now appropriate if the word VMC is used. I still think the summary could be a little more generic yet informative. Anyway all this talk and constant reverts are exasperating I shall have a break, I suggest you read the section on reverts in WP:BRD and a review of WP:IPHUMAN   88.105.45.225 (talk) 00:28, 2 April 2017 (UTC)


 * I'm quite familiar with Wikipedia policy, thanks, and bold-revert-discuss is exactly what is happening here. I'm slightly annoyed that you don't think I'm treating you well enough as well, perhaps you didn't see the comment at User talk:88.105.42.54.


 * I don't mind you reverting my edits if you don't agree with them, but we had discussed beforehand that it should not be 'takeoff power', so I thought I was acting in both our best interests. Indeed, my edit made the summary more 'generic yet informative', which is what you wanted.  Quasar G  t - c 08:49, 2 April 2017 (UTC)


 * I begin with an apology, to reiterate I think your article clean up has greatly improved the article. I previously found the use of reverts in my initial attempts a little frustrating, and the emphasis on using this talk page a little biased.


 * The problem that I see with the summary being too specific is that is easy to be either wrong, or misleading, taking the reader off on a tangent (e.g. orig article) before they have understood what it is in the first place. Yet at the same time a reader with some knowledge may just be looking for an accurate definition of VMC. The irony is this article is not really about the Vspeed of VMC but it is about the phenomenon. For example there is at least one article on stalling, yet no article on Vs. 88.105.45.225 (talk) 11:07, 2 April 2017 (UTC)


 * I know very little about the scientific intricacies of the subject at hand - if there are any small fixes that would make the summary more accurate, then make them without comment. If there is anything that warrants discussion, I will revert your edit and bring it here.  Quasar G  t - c 19:10, 2 April 2017 (UTC)

The article title should be moved back to the singular per WP:SINGULAR. There are thousands of articles that, similarly, feature a number of "types" of the article topic, but are nonetheless titled in the singular. Primergrey (talk) 01:23, 21 April 2017 (UTC)

Now too many errors in this article
I indeed am Harry Horlings, the writer of the original article. I'm a graduate of the USAF Test Pilot School for which the entry level in 1985 was an MSc degree in engineering. I wrote the article because in most, if not all pilot manuals, airplane flight manuals (AFM) and airplane accident investigation reports the minimum control speeds are explained and used in a way that is not in agreement anymore with what is taught at aeronautical universities and test pilot schools around the globe. Somehow, since the mid-80's, the knowledge on the subject faded away at flight schools and investigator training, but not at test pilot schools and aeronautical universities. The original article was indeed quite long. But the article as it is today is not correct, not in agreement with aeronautical science and flight-test princples and practices. Some of the references to academic material were regrettably deleted. By the way, I use airplane rather than aircraft because the aircraft that minimum control speeds apply to are airplanes, i.e. winged aircraft.

Some of the errors at this time:


 * The title was changed to "Minimum control speed", was speeds, because FAR 23 and 25 and equivalent require to determine and publish several Vmc's of the same airplane (Vmcg, Vmca, Vmcl, Vmca2, Vmcl2, Vmca2). So the title should be plural. Vmc was used for 'Vmc in the air', but even FAA publications now use Vmca. Older pilot publications still do not. That is why I used Vmc(a) in the original article.


 * Not all aircaft are certified under FAR 23/25 and indeed some are not even certified. The summary and initial description needs to at least define the phenomenon, before covering the certification basis which is only one part of the story.85.255.237.50 (talk) 17:06, 26 April 2017 (UTC)


 * "The Vmc only applies if at least one engine is still operative". This should be "a Vmc", but since Vmc(a) is also used to calculate rotation speed VR and takeoff safety speed V2, Vmc(a) is also a minimum control speed in anticipation of an engine failure. When one engine is inoperative on a 4 or more engine airplane, the much higher Vmca2 applies (in anticipation of a second engine failure). Refer to Lockheed C-130 manuals where this is explained.


 * The summary could be improved, by making it more generic, to explain that VMC is calculated when one or more engine(s) provides asymmetric thrust, not by making the summary more complicated.85.255.237.50 (talk) 17:06, 26 April 2017 (UTC)


 * "Vmc's are also used by aircraft design engineers for sizing the vertical tail and flight control surfaces of aircraft". This is really where Vmc's start their 'life'. The airplane design engineer already uses Vmc(a) for sizing the fin, because FAR 23.149 and 25.149 require Vmca to be lower than 1.2 Vs (stall speed) and hence, a large enough vertical tail.


 * Citation? I don't doubt its an important consideration. 85.255.237.50 (talk) 17:06, 26 April 2017 (UTC)


 * "They provide a guide to the pilot in the safe operation of the aircraft". Vmc's do not provide a guide, they are listed in the FAA or equivalent approved Limitations Section of an AFM and are therewith "legal" limitations.


 * A reasonable summary, like lines painted on the road, they are neither targets, or absolute limits. Like many other Vspeeds they are exceeded at least twice per flight...85.255.237.50 (talk) 17:06, 26 April 2017 (UTC)


 * "...the aircraft stops responding to the pilot's inputs". No, not true. If a pilot would remove the asymmetrical thrust by closing the throttles a bit, the airplane will respond. It's the aerodynamic controls that are no longer effective.
 * Still reasonable in the summary, you end up with a chicken and egg situation once power is reduced, as a new VMC would apply with a reduced power setting.85.255.237.50 (talk) 17:06, 26 April 2017 (UTC)
 * I realised later that this comment part of the summary but part of the physical description section, I had changed it to paraphase far 23.149 are provided a citation.78.147.49.61 (talk) 02:52, 27 April 2017 (UTC)


 * "...which is why VMCA is simply listed as VMC in many aviation regulations and aircraft flight manuals". Vmc was used in regulations from the beginning, but today, Vmca is already used in (FAA) Flight Test Guides to distinguish Vmca from the other Vmc's. See 1st bullet above.


 * VMC is still referred to in many guides, newspaper articles, encyclopedia entries, Handbooks you name it.85.255.237.50 (talk) 17:06, 26 April 2017 (UTC)


 * "Most test pilot schools use multiple, more specific minimum control speeds, as VMC will change depending on the stage of flight." Test pilot schools indeed teach to determine different Vmc's, because FAR 23.149 and 25.149 require the different Vmc's to be determined and published in the AFM.


 * Not sure what the relevance of 'school' has to this article?85.255.237.50 (talk) 17:06, 26 April 2017 (UTC)


 * "Heavier aircraft are more stable and more resistant to yawing moments, and therefore have lower VMCAs". Heavier aircraft have a larger momentum, but this has no influence on Vmca. Weight has indeed an effect on the actual, the real Vmca that a pilot is experiencing in-flight, because of the side force W·sin phi (which was inappropriately deleted from the article). When banking, a component of the weight generates a sideforce (in the lateral body axis). As the figure (number was deleted) on the left margin shows, the actual Vmca decreases when banking away from the inoperative engine, until the point that the fin is about to stall. The actual Vmca increases when banking into the inoperative engine. When the wings are kept level, Vmca is already 8 - 30 kt higher than the published Vmc(a), depending on the type of airplane, and the sideslip, hence drag, much larger. The regulations require to determine the Vmca at the bank angle for which the sideslip is zero, resulting in lowest drag and a maximum rate of climb. When a pilot initiates a turn at published Vmc(a) and high thrust setting, loss of control can most probably not be avoided.


 * Citation?85.255.237.50 (talk) 17:06, 26 April 2017 (UTC)


 * There are more errors. I'd rather spend my time improving the article than talking further here.

The most important condition for Vmca to be valid was deleted from the article, which is that a pilot, when an engine is inoperative and the airspeed is Vmc(a), should maintain straight flight while also maintaining a small bank angle of a few degrees away from the inoperative engine to avoid the loss of control. Within the coming days/weeks I'll (have to) improve the article, in the interest of aviation safety. Harry FTEof85A (talk) 13:21, 20 April 2017 (UTC)


 * Citation? Actually I think your statement is actually wrong, or at least misleading...85.255.237.50 (talk) 17:06, 26 April 2017 (UTC)


 * I've attempted to address one or two of the points you made above. I've moved the page back to 'Minimum control speeds', made a mention in the lead paragraph about the existence of multiple VMCs and attempted to clarify what is meant by 'aircraft' in this article. I appreciate your attention to detail here, and I agree that we need to make this article as scientifically accurate as possible. If there are any small edits you feel would improve it, then make them (but expect to be reverted per WP:BRD).


 * I would not recommend changing VMC to VMC(a) – this may be a slightly more precise abbreviation, but the average reader will assume that VMC means 'minimum control speed in the air' anyway; adding the '(a)' will only overcomplicate things.


 * Also, you still seem to be missing the main point here. This article is not written "in the interest of aviation safety". It is written as a descriptive piece, for the layman, who has but a basic understanding of aeronautics, and who will never fly a plane in their life. It is not a guidebook for pilots in training: there are textbooks published about this subject detailing what to do if an engine fails, but we aren't trying to replicate those here.


 * Thanks for your time and willingness to discuss –  Quasar G  t - c 17:56, 20 April 2017 (UTC)


 * I've improved what was left of my original article and brought it back to scientific standards, of which I also included the references again. I wrote this article because more than 3000 people got killed during the last 20 years because most publications on the subject are not in agreement anymore with airplane design methods and flight test techniques as taught at aeronautical universities and test pilot schools.


 * I'd like to ask future editors to first review the references before editing this article. Your flight safety is at stake as well. Harry FTEof85A (talk) 11:46, 26 April 2017 (UTC)


 * WIth respect It is NOT your article... Your article should exist somewhere else, but no on wikipedia...85.255.237.50 (talk) 17:06, 26 April 2017 (UTC)


 * Harry, I mentioned on my talk page that you should not make any breaking changes without discussing them. You then promptly made a 6 kilobyte addition to the article, without even replying to my comment above. I have reverted the changes, as they reintroduced some of the issues mentioned here (excessively detailed, overly academic language, etc.).
 * Equally frustratingly, you are still not getting the point. Wikipedia is not written to improve flight safety, and I can almost guarantee that this article will not make any difference to the number of people killed. As mentioned before, this article is written as a descriptive piece, for the layman, who has but a basic understanding of aeronautics, and who will never fly a plane in their life. It is not a guidebook for pilots in training: there are textbooks published about this subject detailing what to do if an engine fails, but we aren't trying to replicate those here. See WP:RIGHT WRONGS.  Quasar G  t - c 15:59, 26 April 2017 (UTC)
 * As can be seen in the (oldest) article history, I wrote the article in Oct. 2013 following reviewing over 400 accident investigation reports. I noticed that in these reports and in most pilot course manuals and airplane operating manuals the minimum control speeds were not presented and explained in accordance with the airplane design and flight-test principles and practises as taught at aeronautical universities and test pilot schools. Somehow during the last 50 years, a gap started to grow between airplane design and operations; I intended to bridge that gap.


 * A minimum control speed article did not yet exist on Wikipedia, so I wrote it. It was reviewed by member(s) of WikiProject Articles for creation and was rated. On 31 Oct 2013, the article was accepted by reviewer Lugia2453. This reviewer even assisted in perfecting the article. It's size was 44kB!


 * During the last two months you and 88.105.39.101 started to edit the article and deleted many lines. Neither of you talked to me, you just did. It seems that you are interested in the number of words of an article, while I'd like to teach people and explain the whereabouts of the subject, being a subject matter expert. Even for a layman, some extra words might help to understand the matter. The article that you put back in place on 26 April contains several errors. Don't say that I "promptly made an addition", because I told you before, on 20 April, about the errors, which version I, as the writer of the original article and as a subject matter expert, cannot accept.


 * You wrote: "I told you not to make breaking changes like this". Who are you and what right do you have to write this. It is you who made breaking changes to a formally accepted and science-based article, while you are not even a subject matter expert.


 * I have added the changes of the next editor (185.69.144.3) to the version of 27 April and aired it.
 * If you again change the article, I will not hesitate to report this and request for a dispute resolution. Harry FTEof85A (talk) 20:59, 30 April 2017 (UTC)


 * You seem to have gained a false sense of security from the fact that it was reviewed by AfC and given a B class. I'm not sure what the reviewer was thinking when they accepted it, but it was certainly not a B class article, as it was largely unreferenced and excessively detailed, read like a guidebook rather than an encyclopedic article, and in places closely paraphrased your paper. In my opinion, it should not have been accepted in that state.


 * Ironically, you are threatening dispute resolution, even though the first step of dispute resolution is trying to reach a consensus on the talk page. You are making edits without doing that, after being repeatedly told not to. Indeed, before I cut down and cleaned up this article, there was extensive discussion (see above) about what should be done. After I made the edits, the IP editor made clear any concerns he had, and made some minor edits. That was dispute resolution. Take it as an example.


 * One of the central pillars of Wikipedia states that anyone can edit its content. It is collaborative, and, unlike published material, nobody owns its content. We had no obligation to "talk to you" when making changes, because this article belongs nobody in particular.


 * I don't want this to get heated, as it will only result in blocks. I hope we can resolve this without anybody else getting involved. Please do not make any more large changes without first discussing them. Thanks –  Quasar G  t - c 21:22, 30 April 2017 (UTC)


 * I am the IP editor responsible for many if not all of the IP edits since March 2017. And while I may got a little frustrated with Quasar a few times, he has in all fairness been fair! He made a substantial improvement to this article. It is clear that FTEof85A has not achieved consensus, as is evidenced by the comments in this section, to make such a substantial change. 78.147.49.61 (talk) 15:56, 1 May 2017 (UTC)

Inadequate Citations and improper use of Citations to Certification (e.g FAR23/25)
In summary this article relies on the following references:


 * 1) Certification regulations e.g. (FAR23/25 and EASA equivalent), which is appropriate when discussing the definition, they do not however provide an explanation of the 'phenomenon' or provide further detail or conclusion, the later occurs in a few places.
 * 2) Several excellent texts are referenced but ironically is only used in the one citation in the summary i.e. 'are typically established by flight tests'.
 * 3) "Control and Performance during Asymmetrical Powered Flight" by Harry Horling which is used as the basis for all other citations. This document while containing many useful facts, also contains a number conclusions, which are essentially the said authors own conclusions, and not necessarily a widely held view.

I propose to fix some of the errors, citing either ref 1, or 2 above, or introducing new texts as references.

Yesterday, I fixed an error in the Physical Description, by paraphasing FAR25.149.

I will fix an error in Vsse today, citing FAA-P-8740-19- Flying Light Twins Safely 94.117.131.114 (talk) 16:15, 27 April 2017 (UTC)


 * Thanks for your changes and additions. Regrettably, other editors deleted many lines and therewith also references to academic books and FAA and EASA Flight Test Guides. Please view Article version: 20:56, 30 April 2017‎. This version contains the refs, but was regrettably undone by Quasar G. within a minute after saving. What do you think of that version?
 * It contains some improvements, but it also worse in many ways, Quasar was right to revert the changes, that does not mean some of your changes should not go forward.78.147.49.61 (talk) 16:04, 1 May 2017 (UTC)
 * The first referenced publication you added, FAA-P-8740-19 - Flying Light Twins Safely is quite good. The only guidance missing is that AFM-published Vmca, after failure of either engine, is valid only during straight flight while banking 5 degrees into the good engine (when the asymmetrical thrust is high). When you keep the wings level or initiate a turn, the actual Vmca increases considerably above the published and indicated Vmca. The second - newer - version of Flying Light Twins Safely though, is not in agreement anymore with what is taught at aeronautical universities and test pilot schools. This version is also downloadable from my website (avioconsult.com), download 8a, in which I included suggestions for improvement.
 * I don't believe to have used my own conclusions in the referenced paper, as you say; all I wrote is based on college books of Kansas University (by Dr. Jan Roskam, see refs), on flight test guides of FAA (see refs) and on course books of test pilot schools (refs), of which I am a graduate.
 * The references to these manuals are also included in the 30 April version of the article. I also included your other changes and the ref to FAA-P-8740-19, but not to the newer version because of the imperfections in there. Harry FTEof85A (talk) 21:27, 30 April 2017 (UTC)
 * With respect your own article has errors and imperfections, also some of the content in your article is not a widely held view. A current document from a reconsidered authority (FAA) is in my opinion a good document to at least consider, in the context of an article that is still poorly referenced.78.147.49.61 (talk) 16:04, 1 May 2017 (UTC)

Stop making undiscussed edits
Harry, I appreciate that you created this article and know a lot about the subject, but you do not own it. You didn't reply to my comments here and don't seem to be be taking no notice of them now. Any large edits you want to make (such as the 6k addition you keep pushing) should be discussed before being made.  Quasar G  t - c 21:01, 30 April 2017 (UTC)
 * You don't own it either, Quasar G. I'll keep my promise, tomorrow. Harry FTEof85A (talk) 21:31, 30 April 2017 (UTC)
 * I know I don't own it, I am simply trying to reach a consensus by discussion. Please see my comments here.  Quasar G  t - c 21:41, 30 April 2017 (UTC)

Dispute, April 2017
Pinging and  regarding the current dispute.

One issue that needs to be addressed before discussing the content is Harry FTEof85A’s citation of his own work (the 2012 Avioconsult paper). Harry, while there is no doubt that you bring a lot of expertise to the article, this comes with risks (specifically conflict of interest and publication of original research here). I urge you to cite yourself only with great caution.

Regarding the content, it is obvious in my eyes that the slightly dramatic and cautious tone of Harry’s version (exemplified by the youtube link, "turning into a killing engine"… yikes) does not belong to an encyclopedia. This has pointed out in the discussion above: Wikipedia is not a manual and the readers should not be lectured. We just summarize the state of current published knowledge.

Nevertheless I do not understand why the section "Factors influencing minimum control speed" has been cut down so much in the current version. Save the tone issue, the content in there is, in my eyes, very helpful in understanding what goes into the determination of a VMC. The figure with bank angle is a high-quality addition that contributes greatly to the topic. I am generally in favor of concision but I would definitely like to restore this part, with more varied citations (seven quotes in a row from the author of the text: we can do better). Thoughts? Ariadacapo (talk) 05:29, 1 May 2017 (UTC)


 * , : I agree that I was a little ruthless with that particular section, and when converting it from bullet points to prose (with my large edit at the start of April) some information was lost. In particular, the effects of the rudder and propeller feathering were cut out, and the bank angle section was simplified a bit too much. The figure could be high-quality, only if it is explained well in the text. If anyone wants to expand on rudder, propeller feathering and bank angles a bit, then please do. But do it gently, and try to keep the language non-technical. Thanks —  Quasar G  t - c 10:59, 1 May 2017 (UTC)


 * This article is currently not perfect, but the recent edits since march are a significant improvement. Harry FTEof85A’s citation of his own work, is a problem as it contains errors and is not perfect. Some might take the view that it is misleading, some may not, however that is irrelevant, as it is his own work and he is entitled to take that view. That does not of course apply to this article.78.147.49.61 (talk) 16:14, 1 May 2017 (UTC)


 * I think the issue with bank angle, is is difficult to be concise and also not misleading, or to misplace the woods while looking at the trees, for example the current graph, why does the blue line rise towards the right? and is that the case for all aircraft... The youtube video is not a good example... Actually the reference from USAF test school is excellent but it spans multiple pages... But I agree that section can be improved, but it should be done using citations as I suggested above!78.147.49.61 (talk) 16:26, 1 May 2017 (UTC)


 * Indeed I intended to edit the section on bank angle, and other factors to make it more balanced (pun not intended) and to cite references to the USAF test pilot document, as well as some other FAA documents not yet referenced that I researched, I will wait until there is some further consensus. In any case I was intending to do it bit by bit as I had been78.147.49.61 (talk) 17:48, 1 May 2017 (UTC)

Proposed Edits to the Physical Description Section
I propose to:


 * 1) Add more citations, the current version only contains one I added a few days a go.
 * 2) add something to state that VMC is NOT just about maintaining straight flight.
 * 3) and VMC is sometimes constrained by lateral limits

These later two points only need to be introduced, in a basic form, but are essential concepts, that need to be considered later in the article. If you agree please consider improving my edits, rather then reverting them?185.69.144.149 (talk) 12:07, 4 May 2017 (UTC)
 * The definition of VMCG is based on a lateral deviation of 30 feet (9.1 m). Is that what you mean by lateral limits? Alternatively, what are the lateral limits on VMC (VMCA)? Dolphin  ( t ) 12:22, 4 May 2017 (UTC)


 * For lateral, I was referring to the case where roll control is the dominant limit in VMC, either in maintaining straight flight or maintaining/recovering control. In any case I think these concepts need to be only introduced in this section, just enough so thay can be expanded on later185.69.144.149 (talk) 22:13, 4 May 2017 (UTC)


 * OK. What do you think of "In some airplanes, aileron authority is more critical than rudder authority in determining VMCA."? Dolphin  ( t ) 00:10, 5 May 2017 (UTC)


 * Yes something like that, with a sentence covering maintaining/recovering control, with citations, we can enhance the whole section so that it ties together nicely. 185.69.144.149 (talk) 22:13, 5 May 2017 (UTC)

I made a number of edits to the Physical Description sections as discussed here. I believe this version covers enough basics with citations to expand on in later sections. Please consider enhancing, rather than a revert, or discuss here first please!78.147.58.160 (talk) 14:22, 16 May 2017 (UTC)

Multi-engine
The V MCA applies when an aircraft loses thrust in at least one engine, but has at least one engine still producing thrust. As such, it can only apply to multi-engine aircraft. Therefore the term "multi-engine" was added.Student8875 (talk) 19:38, 6 November 2020 (UTC)


 * I think your addition is an improvement. Here is another suggestion for improvement. It says Vmc applies to a “multi-engine aircraft (specifically an airplane)”. The word “aircraft” includes helicopters but the definition provided here is only applicable to fixed-wing powered aircraft, commonly known as airplanes. Therefore I think it should say Vmc is applicable to multi-engine airplanes. Dolphin ( t ) 21:53, 6 November 2020 (UTC)