Talk:Helicopter rotor/Archive 1

Untitled
the article was not merged. --Born2flie 18:30, 12 January 2007 (UTC)

Merge proposal to Helicopter

I'm happy for it to be merged, and I'm sorry it shows my lack of Wiki design ability!

However the main Helicopter article is huge, with far too much on type recognition and not nearly enough about what makes them fly or how to control them, their advantages, benefits, limitations and hazards. The Helicopter Rotor page is an attempt to redress this.

Eventually I or some other pilot will have to rearrange the Helicopter page to address these issues. Benet Allen 22:08, 23 December 2005 (UTC)

I agree. The Helicopter article is a bit on the large side. However, this article should be merged... - CorbinSimpson 22:10, 23 December 2005 (UTC)


 * I brought this issue up a long time ago and created a link called Helicopter theory, that was summarily changed by others to Aeronautical engineering. That does not get close to addressing the issue. I don't think this article should be merged with the main Helicopter page. Creating Helicopter Pilotage was a good move also. Madhu 18:41, 25 December 2005 (UTC)

Keep This page has grown substantially and the whole Helicopter topic is branching out in different directions. So far, these have been logical, and I have tried to keep a non-hairy list of interlinks between them. Now we just need to prune the Helicopter article itself! Benet Allen 20:44, 25 December 2005 (UTC)

Keep (agree with Benet Allen)--ChrisJMoor 01:54, 13 January 2006 (UTC)

Parts and Functions
The bullets seem to be mis-indented but I'm not sure where the indented list should finish. Easy fix if you know the topic. 124.180.109.50 (talk) 17:19, 30 June 2013 (UTC)

Two blades


Born2flie: I wonder what the idler links are for? --03:46, 11 January 2007 (UTC)

Born2flie: If you look at the picture here just above the swashplate boot, there is an idler link connecting the rotating swashplate to the rotor mast (which is driven by the transmission). If the blades and their pitch links, or pitch change tubes, were responsible for turning the rotating swashplate, they'd be wrapped around the mast. Even the picture on the left from the Swashplate article shows that there is a mechanical connection between the mast and the rotating swashplate that does not include the rotor blades. --04:06, 11 January 2007 (UTC)

Asymmetry vs. dissymmetry of lift
I changed the reference to asymmetry of lift in het paragraph 'Fully articulated rotors' to dissymmetry of lift. As far as I can see the two terms got mixed. I'd like to see this confirmed? DieterVDW 19:04, 20 August 2007 (UTC)

Confirmed. Your change is good. -Will —Preceding unsigned comment added by Willurd (talk • contribs) 04:46, 16 October 2009 (UTC)

Cross section
Can someone clarify how a rotor is a cross section of an airfoil? I thought a cross-section was a two dimensional slice of a three dimensional object. 70.56.195.231 (talk) 06:13, 29 April 2008 (UTC)jawshoeaw


 * A rotor blade is an airfoil. --Born2flie (talk) 10:24, 29 April 2008 (UTC)

Blade Inspection Method
I've proposed a merge of the stub Blade Inspection Method into this page. I can't see that page ever being able to stand alone. Another option could be to merge to Sikorsky S-61. Fences and windows (talk) 23:56, 25 March 2009 (UTC)

Survey

 * [[Image:Symbol oppose vote.svg|15px]] Opposed. Wow, it is like two sentences? As far as I know, it is only Sikorsky aircraft that use that method to find spar cracks. Unless another manufacturer uses the method, I recommend it be tied to Sikorsky helicopters somehow and not merged to this article. --Born2flie (talk) 00:55, 26 March 2009 (UTC)
 * [[Image:Symbol oppose vote.svg|15px]] Weak opposed. BIM is a Sikorsky process. Unless other techniques are mentioned as well there's little point merging this one. -Fnlayson (talk) 16:42, 10 October 2009 (UTC)

Rigid rotor
Is there some reason rigid rotor is not mentioned under Rotor head design? I thought all the rotor details from Helicopter was copied/moved here. Thanks. -Fnlayson (talk) 23:22, 10 October 2009 (UTC)


 * Fixed by moving text from Helicopter. I think that perhaps we need to remove the text from Helicopter now that it is covered here (almost verbatim). --Born2flie (talk) 00:41, 11 October 2009 (UTC)
 * I removed the articulated, semirigid and rigid sections from the Helicopter article. I left the Antitorque configurations section alone as that is already summarizing what is in this article. -Fnlayson (talk) 01:41, 11 October 2009 (UTC)

All the (unmanned) model quadrotor helicopters that I have ever seen have rotors formed of one solid rigid chunk of material, with no hinges or flexures -- a "fixed pitch blade". Would you say that a "rigid rotor" and "fixed pitch blade" are the same? If so, then what do we call rotors that have a hinge on each blade that allows feathering, but no other motion (neither flapping nor lead-lag)? Would you say that a "rigid rotor" and "fixed pitch blade" are not the same? It seems odd to claim that the kind of rotor with the highest structural rigidity is not a "rigid rotor". --68.0.124.33 (talk) 04:48, 31 May 2010 (UTC)

Semi Rigid
Needs citation for the first six sentences. It is an exact quote from the "Helicopter Oral Exam Guide," by Ryan Dale, and its definition of a Semi Rigid rotor system on page P-22. Will (talk) 05:04, 16 October 2009 (UTC)


 * OK thanks. The wording needs to be reworked so it is not a copyright violation then.  The WorldCat entry for that is at Helicopter Oral Exam Guide for anybody else interested. -Fnlayson (talk) 14:47, 16 October 2009 (UTC)

resonance and other hazards
I'm juggling a lot of projects right now, but will add a discussion of ground resonance and other issues when I have more time. If somebody else wants to contribute, feel free. 165.91.64.214 (talk) 07:36, 16 February 2010 (UTC)RKH

Tail Rotor/ Fan-in-fin
I would be interested in an example of a "Fan-in-fin" or Fenestron with 18 blades?? To my knowledge the Gazelle has the most with 13 blades and the Cabri G2 has the least with 7. --> neither 8 nor 18 look correct to me. —Preceding unsigned comment added by 80.156.44.178 (talk) 10:37, 30 March 2010 (UTC)

bearingless rotor
Shouldn't there be a section on bearingless rotors? — Preceding unsigned comment added by 96.231.37.18 (talk) 20:03, 6 August 2011 (UTC)

Rotor noise
I'd like to see some explanation of rotor noise, especially the characteristic whop-whop-whop of UH-1s and similar craft. An episode of Nova said it was from sonic booms coming off the rotor tips. Is this true? --Triskele Jim (talk) 16:23, 7 October 2011 (UTC)
 * If you hear a repetitive whishing sound, you are hearing the rotors interacting with the air, similar to putting your hand out the window of your car when driving on an expressway. If you are hearing a hard chopping sound, then you are hearing sonic booms from the point on the rotor that is travelling at the speed of sound.  That is part of the reason these machines are sometimes called choppers.  If you reduce the rotor speed, but increase the collective angle of attack, then you might be able to push the sonic boom right off the end of the rotor blades, but most helicopters do not have the correct characteristics to pull this off.  Nutster (talk) 02:41, 19 September 2017 (UTC)

I would really like to see a section on how, exactly, and mathematically, lift is generated
The wikipedia article on lift does not have a section on lift generated by a rotor, or for rotorcraft, which seems to be inherently quite different from what that article describes (since the rotor changes the pressure of the air around it, it would seem). If anyone has any response, input, or opinion, please share. I have no real experience in this - I am quite ignorant, to be honest, of the mathematical way for lift to be calculated by rotory wings. So please help me understand, and we can possibly improve the article too.


 * Here are some sources:


 * http://www.heli-chair.com/aerodynamics_101.html
 * http://www.aerospaceweb.org/question/aerodynamics/q0015b.shtml
 * http://helicopterflight.net/lift_equation.htm (post to be further completed later) 69.230.116.144 (talk) 17:32, 13 April 2012 (UTC)


 * It's a rotating wing, so the airfoil works very much like the wing (creating lift) on an airplane. -- T HE F OUNDERS I NTENT  PRAISE 18:45, 13 April 2012 (UTC)


 * okay (so you'd agree that the velocity of a rotorcraft itself doesn't effect the force of lift, and that those sources I gave are mistaken, then, I'd assume), but (as I asked before) doesn't the rotary wing cause the pressure of the air change drastically? (this is the main thing I think should be addressed.  This change in air pressure, if it does occur, should be accounted for in the equation for lift)  Also, I would like to address the fact that the linear velocity of the rotary wing changes as a function of its distance from the center.  I think that these two differences from normal "wings" are major enough to warrant a section on lift created by rotary wing either in this article or the one on lift. 69.230.116.144 (talk) 20:24, 13 April 2012 (UTC)


 * Lift is an interesting topic with some fallacies and controversies involved in its explanation (or purported explanations). See the article lift (force). The following may not be directly relevant to your question, but it's an interesting side of the topic of lift (force). That article talks about, for example, the "popular" explanation based on "equal transit time" over and under the wing and its supposed pressure differential. At the silliest end of the fallacious extrapolations from this notion, people claim that the power output from the engines is not actually used to lift the aircraft and hold it airborne—but that's pretty obviously nonsense when it's a hard economic fact that a loaded Lockheed C-5 Galaxy needs big-ass engines to get up and stay up, instead of trifling little ones. Not so different for a loaded Boeing CH-47 Chinook, either, although in that case the wings are rotary. So the real physics of lift are not quite as simplistic as that schoolkid version. I'm not a physicist, but I gather that in reality it has more to do with pushing on the air below, doing work on it in the physics sense, expending energy, than with pressure differentials per se, as if low pressure above the wing simply "vacuums" the aircraft upward like a good hoovering or something. Anyhow, sorry for the digression, but wanted to share the links to lift (force) and to wing. — ¾-10 23:49, 13 April 2012 (UTC)

"Kopp-Etchells effect"
In 2009, war correspondent Michael Yon referred to this corona effect as the "Kopp-Etchells effect" to honor Cpl. Benjamin Kopp and Cpl. Joseph Etchells, recently fallen American and British soldiers, respectively.[29]

And I call it the delicious macaroni&cheese effect. Sorry, this is totally irrelevant what some random guy calls it as a tribute to some other random guys. This is an encyclopedia and not a yearbook. — Preceding unsigned comment added by 178.190.51.76 (talk) 12:03, 21 July 2013 (UTC)

I also see no reason why a physical effect should be given a political name. Futhermore the citation looks like advertisement and is the single source of the attribution of the names KE to the physical effect. — Preceding unsigned comment added by 128.90.14.49 (talk) 14:29, 9 June 2014 (UTC)

Assessment comment
Substituted at 17:35, 29 April 2016 (UTC)

Wrong picture
The first picture claims to show the rotors of a helicopter, but in fact it shows a technician (I hope) beside the helicopter's propeller instead. Can someone put in a picture of the rotors instead? Nutster (talk) 02:45, 19 September 2017 (UTC)

Flapping hinges
One thing (out of several) which is not clear from this article is what keeps the blades generally straight or from the hub of they are free to flap and trail, etc? If a blade has a hinge that allows it to move up and down independently, why when lift is created do the blades not lift to the maximum amount allowed by the hinge and stay there? It is like describing a folding wing on a navy jet that doesn't lock into place, yet stays in the proper place when you try to lift a plane with it. I kind of understand the lead and trail hinge, the centripetal force would tend to return the blades to the straight out position after the added force equalizes, but is that enough to overcome the thousands of pounds of lift created by the blade? And wouldn't this same hinge cause the blades to droop significantly when the rotor stops? Is that why blades do drop when the craft is idle, not because flexure in the blades? Also the text seems to describe an image of an R22 rotor hub, but it is not visible on my screen. 2600:1000:B14A:6023:0:4C:E5B0:9B01 (talk) 02:32, 23 November 2022 (UTC)