Talk:Rotorcraft

The following is a closed discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the proposal was

to merge in the absence of objections. --Born2flie 03:40, 16 February 2007 (UTC)

Merge

Born2flie: There is a merge recommendation on the article page. --01:32, 1 January 2007 (UTC)

Merge

• Born2flie: I recommend the article Rotary-wing aircraft merge to Rotorcraft. --01:32, 1 January 2007 (UTC)

Don't Merge

The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

US Bias

"A qualified applicant receives a pilot license in the category of rotorcraft, with a class rating for either helicopter or gyrocopter, depending on which aircraft is to be flown." This page is supposed to be about the kind of aircraft, not the United States FAA Catagory rotorcraft. I'm changing the page to specify which information is US specific. 24.22.24.208 (talk) 04:05, 17 February 2008 (UTC)

Please be a bit more careful tossing around "bias" allegations. This probably more a case of where the source information came from, and how easy it is to access such information. A better term to use would be "US focus", which avoids the appearance of an anti-American bias on your part. So rather than putting down the original contributors, simply add more information. Be sure to use and cite reliable sources, or your additions will be removed. Also, be sure your changes to the info that is there doesn't stray from the original sources. - BillCJ (talk) 04:32, 17 February 2008 (UTC)

Also, be aware that while many contries have Wikipedias in their own nation's primary languages, Americans are not so fortunate. They have to share Wikipedia with Britan, Canada, Australia, various other Englsih-speaking countries, and any one else in the world who (often barely) speaks English. There are almost 300 million speakers of Englsih as a first language in the USA, which most people from the rest of the world do not realize is more people than those in all other primairily-English-speaking countries. So please, be a litte patiet if the start of an article is primarily USA-focused. We're not from Latvia, you know - how many people from Africa or South America can read Latvian? - BillCJ (talk) 04:40, 17 February 2008 (UTC)

Okay, you're right, those were some harsh words. Although, I know I'm not racist against Americans because I'm American myself. Anyway, the page is less US focused now, and I'll get some good references shortly. 67.160.147.2 (talk) 01:26, 18 February 2008 (UTC) (I'm the "US bias" guy, from a different computer).

Proposed new sections on rotor configurations

I am thinking off adding a new section explaining the various twin-rotor layouts etc. Also something on fixed-rotor hybrids/compounds, maybe as a subsection to it. Please see here for details. -- Cheers, Steelpillow (Talk) 17:31, 14 June 2008 (UTC)

Done. -- Cheers, Steelpillow (Talk) 10:31, 20 June 2008 (UTC)

Well done. 24.20.131.232 (talk) 09:00, 29 June 2008 (UTC)

SNECMA Coléoptère wasn't even a propeller-driven coleopter, much less a rotorcraft.[1][2] The coleopter concept centers around an annular wing, not around a rotor turning about the fuselage. The tiltwing doesn't use rotors or even proprotors. It has propellers and is a VTOL aircraft, not a rotorcraft. The X-Wing, Triebfleugel, and PA-97 never made it to production, the Triebfleugel never made it beyond wind-testing of aerodynamic models. All per the Wikipedia articles and online references. --Born2flie (talk) 15:57, 20 September 2009 (UTC)

Article image

The image of the AS332 in the Infobox neither adequately demonstrates the unique configuration of a rotorcraft, because you cannot easily make out the rotor system due to the background, nor does it depict a unique use of a rotorcraft, because firebombing is primarily done by fixed-wing aircraft. I have not perused the commons or other helicopter images, but if an image is going to represent this article, I believe it should accomplish both. --Born2flie (talk) 17:19, 11 January 2009 (UTC)

Not rotorcraft at all?

Born2flie has deleted the tiltwing and coleopter from this article on the grounds that they are VTOL aeroplanes rather than hybrid rotorcraft, claiming also that the SNECMA Coléoptère didn't even have a rotor. I would suggest that the coleopter had a ducted rotor, and that both it and tiltwings are as much rotorcraft as the tilt-rotor concept is. Opinons, please? - hard references even better. -- Cheers, Steelpillow (Talk) 21:02, 20 September 2009 (UTC)

Perhaps you could tell me what your acceptable references would be? You added the information into the article without references. I assumed good faith and those edits stayed until I did a little checking on the aircraft themselves. I've included two links above that clearly show the SNECMA Coléoptère was not a rotorcraft, and the article on coleopter aircraft is a discussion about an annular wing (which is neither a ducted rotor nor ducted fan).[3] You offer no reference to show why your previous edits should remain, and according to the guidelines, the burden of proof is on the editor who wishes to include the information, not on the editor who deletes for lack of references. --Born2flie (talk) 04:58, 22 September 2009 (UTC)

Well, there's the main issue - when is a rotating aerofoil a rotor and when is it a propeller? "The rotor-propeller of the tilt-wing aircraft performed the dual task of a rotor in hovering and a propeller in forward flight"[4]. So for a tiltwing it does act as a rotor after all. The article you reference for the coleopter clearly shows a rotary aerofoil within the annular wing - the fact that the wing is annular does not negate the existence and posistion of the rotary aerofoil, no matter what the focus of any particular study may be. As for the The X-Wing, Triebfleugel, and PA-97 never made it to production, it is absurd to suggest that an aircraft type must go into commercial production before it can go on Wikipedia. With reference to policy, when Challenging another user's edits: "Any editor has the right to challenge unsourced material by opening a discussion on the talk page or by tagging it. Material that should be removed without discussion includes contentious material about a living person, clear examples of original research, and anything that is ludicrous or damaging to the project." I am not aware that my edits fell into any of the latter categories. Further, there is no need to provide citations for well-known facts - an editor need only do so if challenged. I belived my remarks to embody well-known facts. You evidently do not. Please do not pre-emptively delete edits again, but challenge them in accordance with policy. Many thanks. -- Cheers, Steelpillow (Talk) 16:38, 22 September 2009 (UTC) updated -- Cheers, Steelpillow (Talk) 16:55, 22 September 2009 (UTC)

Sorry, only just spotted your remarks in a previous section. The coleopter concept may not require a rotary aerofoil, but the only example/s built did so. Maybe my text needs revising and some citation - but not wholesale deletion. -- Cheers, Steelpillow (Talk) 17:00, 22 September 2009 (UTC)

Considering that your edits included erroneous conclusions about most of the aircraft in the face of the available references, I felt it safe to assume, in light of my previous assumption of good faith, that a portion of your edits were indeed WP:OR, and therefore not requiring discussion to remove. I actually made the attempt to verify whether an aircraft or aircraft type was considered to be a rotorcraft by reviewing what references I had available or could even find.

1. To make the argument that any coleopter is a rotorcraft in absence of a bonafide reference will require WP:SYNTH, such as looking at a picture and declaring it to be rotor. So, I have to ask if you even reviewed the references I provided above, or in the section further above, about the coleopter or did you just look at the picture (artist concept) on the first page.
   • The SNECMA aircraft was built around a turbojet engine that had previously shown sufficient power to lift an aircraft vertically, not a prop, not a rotor. Flight magazine has quite extensive coverage on the aircraft. To continue to suggest otherwise is quite obtuse.
   • The Heinkel Lerche design mentioned in the coleopter article envisioned contra-rotating propellers.
   • Even the Hanneton design you refer to is described later in the article as being powered by a turboprop, not a rotor. But based on your description of the aircraft, I have to wonder if your definition of a rotor isn't something overly simplistic, such as an airfoil that rotates.
2. I never said that the three aircraft currently still in the article had to be produced to be included in Wikipedia. Two of them were actually built prototypes or were in the process of prototype development (PA-97 and X-Wing), the third only achieving wind tunnel model testing (Triebfleugel), and one of them was flown in its designed configuration (PA-97). My edit comment merely highlighted my adjustments to the prose to point out the fact that these aircraft have never entered production.
3. I've reviewed the reference you included regarding the Vertol VZ-2, and I can begrudge you that this individual aircraft has a sembleance of a rotorcraft based on the design and control of its rotor-propellers, per the article: "The rotor hubs of the Model 76 incorporated flapping hinges..." (p.608). However, the predominance of tiltwing aircraft are generally accepted as VTOL aircraft, but not as rotorcraft, based on the references I have been able to review, in that they use larger or greater numbers of propellers to generate the thrust for vertical takeoff, rather than rotors. Consequently, I would accept the VZ-2 as a hybrid rotorcraft/tiltwing, but I would not agree that one instance legitimizes the entire class of tiltwing as rotorcraft. --Born2flie (talk) 18:42, 22 September 2009 (UTC)

OK I concede the point about the SNECMA Coleoptere. That leaves the tiltwing. IMHO if some examples are deemed to have rotors then they deserve a mention. Whether all examples come under the heading of hybrids and compounds, or just those few, is something I'd like to see wider consensus on. As for my deleting some of your additional edits along with reverting your pre-emptive deletions, perhaps you did not spot the apology made in my edit comment and the explanation given. At least the article is improving, which is the main thing. -- Cheers, Steelpillow (Talk) 20:19, 22 September 2009 (UTC)

What difference is being cited to differntiate between the tiltrotor and the tiltwing? In my mind the only difference is the pivot point, and they should be included under the same category where possible. Obviously they're seperate concepts; I'm not saying to roll them into one. I just don't get how one can be VTOL and one can be a rotorcraft without the other being the same. -SidewinderX (talk) 20:27, 22 September 2009 (UTC)

SidwinderX, I'm not sure I understand your question. An aircraft can be a rotorcraft and VTOL, and an aircraft can be VTOL without being a rotorcraft. A rotorcraft derives its primary source of lift from a rotor, which is distinctively different from a propeller, regardless of their similarities in function. All tiltrotors use helicopter-style rotors to derive their lift for vertical takeoff as well as for their propulsion during fixed-wing mode. So far, only the Vertol Model 76 (VZ-2) has been referenced to show that it uses rotors in the tiltwing configuration to do the same job. The XC-142, the X-18, Vertol-NASA tiltwing, CL-84, Ishida, etc., were planned, designed, or built to use propellers. I allow that my review of my references may be in error and welcome any references that substantiate information to include into the article, as I have with the Vertol VZ-2. --Born2flie (talk) 05:15, 23 September 2009 (UTC)

This from Flight describes the situation as "While the tilt-rotor has rotors that tilt to become propellers, the tilt-wing has propellers that tilt to become rotors. Propellers are designed to operate with air flowing through the disc whereas rotors have also to operate with air flowing across the disc" My reading is in both cases at some point those big spinning things are acting as rotors. GraemeLeggett (talk) 15:09, 25 September 2009 (UTC)

My reading is that the tiltrotor's rotor tilts forward to provide forward thrust as a propeller would, and that the tiltwing's propeller tilts upwards during takeoff and landing in order to provide upward thrust in the same function as a helicopter's rotor. The issue isn't in the direction the device is pointed, but the design of a propeller versus a rotor. Rotors are designed to account not only for the aerodynamics and physics related to lifting/thrusting upwards, but also for those that occur during translating flight as the rotor moves knife-edge through the air (i.e. dissymmetry of lift, retreating blade stall, etc.). The issues that the Bell XV-3 experienced during its development, and specifically the wind tunnel testing at the end of the program, highlight the unique problems experienced during converting the position of the rotors, compared to converting the position of a propeller. The structures of a rotor and propeller are different, therefore the aircraft are different, even if the structures are sometimes employed in similar means of lift/thrust. --Born2flie (talk) 22:34, 26 September 2009 (UTC)

Do we distinguish between propeller and rotor by design characteristics or by usage, i.e. does a tilted rotor act as a propeller or become a propeller? GraemeLeggett provides a reference in support of the latter - Born2flie or someone needs to do the same for the former. It may be that opinions differ within the aviation community, in which case it would seem appropriate to mention this issue in the article. But first let's gather some more evidence. -- Cheers, Steelpillow (Talk) 16:36, 27 September 2009 (UTC)

(Deindent) The singular Flight article hardly constitutes an authority on what determines a rotor versus a propeller. In fact, the article in question clearly labels the airscrews on the Ishida aircraft as propellers, not rotors. So, the descriptive reference to their altered function is simply that, a description. Since some seem to need a primer on what constitutes rotors versus propellers, please accept the following published by an organization that actually includes rocket scientists [5]. Perhaps we can accept this discussion on a physics forum,[6] perhaps not? Here's a "WikiAnswer" from Answers.com.[7] Basically, Again, the difference between a rotor and a propeller is design and control. The rotor blade is designed to attach to the hub in such a way as to allow it to flap and hunt (lead and lag). Rotorcraft controls allow the pitch of each blade to be changed independently in sequence during a rotational cycle, and most rotorcraft (some autogyros excluded) allow the pitch to be changed altogether at once, collectively. The rotor allows for translational flight, perpendicular to the axis of the rotor shaft or mast. A propeller is fixed with the exception of the ability of the blades to twist to change pitch angle. The propeller can only direct the aircraft in a direction parallel to its shaft. The rotors of all rotorcraft can provide lift in translational flight (again, perpendicular to the rotor shaft axis), the rotors of all rotorcraft except autogyros can provide thrust and lift together (at the same time) in translational flight. --Born2flie (talk) 03:47, 28 September 2009 (UTC)

Trying to make the issue more abstract. If I was to take a just an engine and an "airscrew" sit it screw uppermost tether it with wires and start the engine. It pulls itself up into the air. I throttle back the engine and it hovers. But its not a rotorcraft, its just pulling itself up because it has more thrust than weight? If I cut the power it falls to the ground - if I do the samething with a helicopter it comes down like a sycamore seed. And this is why some tilt designs are lumped in with the Harrier and its kin by the US FAA? GraemeLeggett (talk) 11:10, 28 September 2009 (UTC)

Tiltrotors have autorotational capability. Not necessarily survivable at the bottom, but it does have the capability to enter an autorotation. Most advanced rotorcraft, with heavier gross weights, fall at rates closer to a rock than the twirling, descending sycamore seed. This ability is also due to the design of the rotor compared to the design of the propeller.

The FAA's definition[8] may explain why they lump the tiltrotor in with the Harrier as Powered Lift:

Powered-lift means a heavier-than-air aircraft capable of vertical takeoff, vertical landing, and low speed flight that depends principally on engine-driven lift devices or engine thrust for lift during these flight regimes and on nonrotating airfoil(s) for lift during horizontal flight.

ICAO does not necessarily agree with the FAA's definition, and has had difficulty coming up with its own suitable definition for the tiltrotor. But if you make the argument above, then perhaps you're suggesting that neither tiltrotor nor tiltwing belong in this article? Especially in light that the international organization responsible for the international standards and recommended practices of aeronautics doesn't officially recognize them as rotorcraft. --Born2flie (talk) 16:07, 28 September 2009 (UTC)

I'm more verbalising my own thoughts and understanding of what might/might not be rotorcraft. The OED defines rotorcraft as a name to cover rotary wing aircraft which isn't much help as rotary wing is a redirect to this article and rotor leads you to helicopter rotor. I think we need some definitions (hence my looking through Flight). It may yet be that we will end up with tiltwings off on their own but we could certainly use some coverage of rotary wing outside helicopters alone. GraemeLeggett (talk) 18:36, 28 September 2009 (UTC)

I hope we can all agree that a rotor is a lift device, and on a helicopter it is engine-driven. According to that FAA definition above, any rotorcraft whose rotor is offloaded onto the wing for forward flight, including the Osprey and the Fairey Rotodyne, is a powered lift. That same FAA reference also gives this definition; "Propeller means a device for propelling an aircraft that has blades on an engine-driven shaft and that, when rotated, produces by its action on the air, a thrust approximately perpendicular to its plane of rotation. It includes control components normally supplied by its manufacturer, but does not include main and auxiliary rotors or rotating airfoils of engines." Unfortunately, the page does not define the "rotor" which it excludes.

Historically, let us not forget those early rotorcraft such as the Cornu helicopter in the days before Cierva developed his articulated rotor to work along with Pescara's cyclic pitch control. By User:Born2flie's definition these early efforts are unfit to be called rotorcraft.

IMHO, rather than try argue our way through all these inconsistencies with the most obstinate one winning, it is best to keep a single overview of all these hybrids, compounds and are-they-aren't-theys, in one page. I initially put it in this article, because there was little other useful content here at the time and back then I could see no need for a separate article. Perhaps times have changed and we need to split this article into two, although I am not sure what sane title we could give the odds'n'sods article. I'd prefer to keep everything here, even though one man's tiltwing may not be another man's rotorcraft. -- Cheers, Steelpillow (Talk) 19:02, 28 September 2009 (UTC)

Please, don't mistake my tenacity for obstinacy. Even by the FAA's definition, Cornu's aircraft could still qualify as a rotorcraft, which is why the lawyers come up with these definitions and not the editors on Wikipedia. Still, one would be hard-pressed to insinuate that Cornu installed propellers atop his device in order to achieve vertical lift. But then, people have been arguing the aeroplaniness of the Wright brothers' craft for over a century now. By the same arguments we've seen here, some might be envisioned to argue that the SNECMA Coléoptère is a rocket ship because it takes off the same way a rocket does, being thrust upwards by exhaust from an engine.

While ICAO has not qualified exactly what a tiltrotor is through any official definition (as of 2004), they have admitted that it is different from conventional rotorcraft, implying a rotorcraft but being from a powered lift (VTOL) category of aircraft. ICAO disagrees with the FAA that powered lift aircraft require their own specifications and recommended procedures apart from what exists for conventional helicopters and conventional turboprop fixed-wing aircraft. Also according to ICAO, the powered lift category includes tiltwings, harriers, etc., and those aircraft other than tiltrotors described as having rotorcraft ability without rotorcraft design and features. I would recommend that tiltwings generally be covered in the Powered lift article in keeping with the ICAO view on the matter.[9] --Born2flie (talk) 03:51, 29 September 2009 (UTC)

The powered lift article currently discusses two related titltrotors (complete with reference) but no tiltwings. OTOH User:Born2flie has moved tiltrotors firmly out of the "hybrids and compounds" grouping and into rotorcraft. The ongoing ICAO vs. FAA spat highlights how hard it is to agree on these things. Some craft such as the Fairey Rotodyne can take off under rotor power but fly supported by wings alone, with the rotor trimmed to idle - are these powered lifts or rotorcraft? I just want to see all our weird and wonderful examples discussed and compared in one place. The ICAO document referenced also says, "All of the different technologies that produce V/STOL and VTOL capabilities are classified as Powered Lift. The tiltrotor technology is comprised of conventional aircraft fuselage with wing-mounted outboard nacelles that contain the engines, transmissions, and prop-rotor discs." Note that it stops short of calling the rotating aerofoils "rotors", but lumps tiltrotors in with the other powered lifts. Will everyone accept if we do the same? -- Cheers, Steelpillow (Talk) 18:05, 29 September 2009 (UTC)

The Fairey Gyrodyne's rotor auto-rotates in the same manner as an autogyro, the stub wings give extra lift as well as carrying the engines.GraemeLeggett (talk) 20:56, 29 September 2009 (UTC)

(deindent) I'm curious what would make Steelpillow (talk · contribs) happy in this situation? --Born2flie (talk) 22:30, 29 September 2009 (UTC)

Read my lips: "I just want to see all our weird and wonderful examples discussed and compared in one place." We seem to be agreeing on the Powered lift article. -- Cheers, Steelpillow (Talk) 11:59, 30 September 2009 (UTC)

It was not clear to me that you were meaning that you felt tiltrotor and tiltwing should both be covered in powered lift at that point. I can agree to that. --Born2flie (talk) 12:57, 30 September 2009 (UTC)

RE: Fairey Rotodyne. In addition to the point GraemeLeggett makes, H.A. Taylor (Fairey aircraft since 1915, 1974) states that the rotor provided 50% of the lift in cruise flight. Since the rotor provided lift from takeoff to landing, and only relinquished half of the load in cruise flight...you do the math, but I think that leaves the rotor providing a plurality of the lift.

RE: Tiltrotor/Tiltwing. If ICAO lumps them into powered lift and stops short of calling them rotorcraft, I have no problem if they migrate to powered lift and are no longer included in rotorcraft. If powered lift and rotorcraft are both considered VTOL categories, then it seems illogical to include an aircraft in both categories based on their definitions by the ICAO, regardless of either how similar it appears to function compared to another aircraft, or how similar the structures appear to another aircraft. The use of a rotor structure should then be limited to the discussion of the aircraft group in the appropriate article, or in the article about the individual aircraft type. Use of a rotor structure should also then not be used to classify rotorcraft beyond the example of ICAO and its member states[10] (helicopter and gyroplane),[11] or beyond the stated design of the inventor (Cornu, gyrodyne, etc.). --Born2flie (talk) 22:30, 29 September 2009 (UTC)

OK, I just moved lots of stuff over to Powered lift. Apologies if it's a bit rough and ready, hope others of you can take it from there. -- Cheers, Steelpillow (Talk) 14:40, 30 September 2009 (UTC)

Ducted rotor?

Steelpillow, the ducted rotor and ducted fan both sound like powered lift configurations. In fact, they may be variants of tiltwing and coleopter technologies if the duct is utilized as an annular wing and not just to maximize thrust of the rotor/fan. Do you want to move this section over to Powered lift as well? --Born2flie (talk) 16:30, 30 September 2009 (UTC)

Thanks, I missed that one. I have now jammed it into the Powered lift page. The topic needs some thought to set out properly, but at least it's on the right page. As I now recall the original Coleopter concept was as an integrated wing-fuselage-propulsion system, with early plans assuming that a prop/rotor variant would be the first to fly. It was only when the marketplace showed little interest in the "cheap-and-cheerful" prop/rotor runabout and then the Atar turbojet delivered sufficient thrust sooner than the Coleopter team expected, that plans changed and the jet variant was built first. Of course you already know how reliable my memory is, nevertheless the story should illustrate how careful we need to be in documenting the little critter. -- Cheers, Steelpillow (Talk) 21:15, 30 September 2009 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Rotorcraft/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

Born2flie: Article should briefly cover key points of all rotorcraft types and reference, via {{main|article}}, those articles that are already established (e.g. Helicopters). --03:30, 8 January 2007 (UTC)

Last edited at 03:30, 8 January 2007 (UTC). Substituted at 04:57, 30 April 2016 (UTC)

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