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On 6 January 2023, it was proposed that this article be moved from Flight dynamics (fixed-wing aircraft) to Aircraft flight dynamics. The result of the discussion was moved. |
OK we can definitely do better than this stubby article. It's not just orientation and control -- it's orientation, change of orientation due to the forces acting on the body, and then the control to maintain a specific orientation or another desired condition. Lets hear about the state space model, the perturbation equations, the stability derivatives!
The positive X axis, in aircraft, points along the velocity vector, in missiles and rockets it points towards the nose.
in missiles and rockets it points towards the nose? wtf. "it's"?
The article needs to explain that yaw increases with clockwise rotation as seen from above. Pitch increases as we tilt upwards. Roll increases as the right wing dips. The picture is wrong on all three counts.
I find the introductory definitions of yaw, pitch and roll quite confusing. Do these angles fix the orientation of the aircraft in absolute terms (based on fixed north–south, east–west and up–down axes), or do they only describe *changes* in attitude relative to axes based on the plane's current orientation?
For example, suppose an aircraft has a pitch of 10 degrees and a roll of 20 degrees. I imagine this to mean that the nose-to-tail axis is first pitched up 10 degrees to the horizontal, and the aircraft is then rotated 20 degrees about its nose-to-tail axis. If the aircraft now pitches up a further 5 degrees then is that 5 degrees a rotation about the wingtip-to-wingtip axis, or about a horizontal axis?
Similarly with yaw. Does it make sense to say an aircraft has a yaw of 30 degrees, and if so 30 degrees relative to what? Or does a yaw of 30 degrees just mean the aircraft has *changed* heading by 30 degrees and could actually be pointing in any direction? And is the yaw axis always vertical, or is it perpendicular to the nose-to-tail and wingtip-to-wingtip axes, and therefore varies depending on the aircraft's current attitude?
The "Coordinate systems" section, which I hoped might clarify, actually does nothing of the sort. It says that "the pose of an object" is described as follows:
"The positive X axis goes out the nose of the airplane The positive Y axis goes out the left wing of the airplane The positive Z axis goes out the top of the airplane
Roll, pitch and and yaw constitute rotation around X, Y, and Z, respectively. The directions of all three elements are depicted in the picture above."
This makes no sense, because if the axes are relative to the object then there is, at any time, never any rotation about any of the axes, so these angles can at best describe only changes in the "pose" of the object, not the "pose" itself.
I could go on, but I'll just conclude by saying I think this stuff need a rewrite by someone who fully understands it. 00:36, 23 July 2006 (UTC)
Correct: the absolute alignment of the inertial axes (Earth axes) would only be important if the motion of the Earth contributed significantly to the total motion. Body axes are fixed with respect to the body, and move with respect to Earth axes. Wind axes are fixed with respect to the velocity vector and also move with respect to Earth axes. We are considering straight and level flight where the wind axes are initially aligned with Earth axes. In other flight conditions, there would be an initial large angle orientation to take into account in the equations of motion. I think the fact that for this particular design case, the two axes sets are initially aligned, is the source of the confusion. Perhaps analysis of the dynamics in a steady dive might help clear this up. Gordon Vigurs 18:47, 27 July 2006 (UTC)
I fixed two problems in the coordinate section: You cannot calculate orientation from the angular velocity, and inertia is not a vector (it's a tensor). --Jrvz 14:16, 27 July 2006 (UTC)
Incorrect; orientation is calculated from angular velocity by integration of the quaternion rates of change, each of which is a linear combination of the angular velocity components. Alternatively, and not to be recommended, the Euler angle rates of change may be calculated from the angular velocity, and integrated with respect to time. Finally, the direction cosines rates of change are also linear combinations of the angulatr velocity components, these also may be integrated to generate the rotation matrix, provided measures are observed to retain orthogonality. These are the methods used most frequently both in simulations of atmospheric flight vehicles and in inertial navigation. Not only can the rotation matrix be calculated from the angular velocity, this is in practice the preferred approach. Gordon Vigurs 20:28, 27 July 2006 (UTC)
Nobody ever claimed inertia was a vector, or even implied it. Gordon Vigurs 18:16, 27 July 2006 (UTC)
This article, Spiral divergence, Phugoid, Dutch roll, and Instability modes of an aircraft overlap a lot and should probably be brought into agreement with one another. -68.59.121.204 03:30, 1 September 2006 (UTC)
a much better reference is the model presented by Robert Stengel in his book on Flight Dynamics.
A mass as the inertia formally exists in his model wheres inertia is removed in this presentation. A pilot has a mass and a weight in Stengel's theory of flight.
This is a very importent thing to get correct for the FAA needs to correctly determine the flight theory. This aspect or weight of the aircraft confounds pilot training and good reference in flight dynamics is hard to find.
on page 49 of "Flight Dynamics" the whole evelope is state in a single Hamiltonian function. And the equation 2-3 states weight!!!!!!!!!!!!!!IN euler-angle representation.
And the absolute elegence of the Hamiltonian presentation far outweighs the other aspect.
Maybe another wiki section on Stengel's Hamiltonian method can be added?
--207.69.139.156 15:40, 28 October 2006 (UTC)
--Eaglesondouglas 00:01, 13 November 2006 (UTC)
I tagged the article for cleanup because of redundancies, gaps, and technical inaccuracies, especially in the beginning. Some of these problems have been discussed above. I made a first run at tackling these issues, and hope to see more people join in. Dhaluza 16:04, 16 December 2006 (UTC)
Somehow I cannot transform this into text. Arnero 21:16, 22 March 2007 (UTC)
Would it be possible to change the picture demonstrating yaw, pitch and roll? The current one gets the point across fine, but is too 'cartoony' and detracts from the article in my opinion. Thanks! 82.37.152.185 20:59, 26 March 2007 (UTC)
It's still cartooney and confusing
I see the date on the picture is August 2007. Today is 8 April 2009 It looks like the picture was changed or altered since those (old now) comments. I am confused though because I've always thought the current picture is cartoony and confusing. I was fixin' to make a comment in a new section when I saw this stuff (above). I'll look around for a better diagram, or make one - eventually. Anyone have something suitable sooner?
--Gummer85 (talk) 02:03, 8 April 2009 (UTC)
This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 09:51, 10 November 2007 (UTC)
(source -> destination)
Inertia
Arnero (talk) 12:59, 21 September 2008 (UTC)
...looking through all these lateral stability derivatives... what about yaw moment due to pitch velocity and pitch force due to roll rate and things like that for spiral mode? —Preceding unsigned comment added by 87.115.151.21 (talk) 16:37, 9 April 2009 (UTC)
I think we use Zw and Mw for Zalpha and Malpha... as in mw = zw x staticmargin as well as v for beta as above... maybe there are different conventions between the USA and UK on this? —Preceding unsigned comment added by 87.115.151.21 (talk) 16:43, 9 April 2009 (UTC)
Mathematical mistake: mass is a constant, so it should remain after taking the derivative.
I will change the mistake in article. It doesn't affect the outcome (because the term will be neglected as unimportant in the next sentence), but makes it correct. —Preceding unsigned comment added by 213.35.207.11 (talk) 13:10, 15 November 2008 (UTC)
see the image description at
Also, regarding the NASA pitch movie; arent the 2 wing rudders also used ? KVDP
What is missing here is any hint how these notions apply to helicopters. --Bernd.Brincken (talk) 12:24, 11 December 2010 (UTC)
The article seems to have a predominant, but unstated, assumption through most of the prose that we are talking about aircraft flight dynamics, despite the scope in the lede paragraph being explicitly defined as "the science of air and space vehicle orientation and control in three dimensions." It seems to undercover spaceflight dynamics.
My sense is we ought to balance it a bit, and clearly section the article into major sections that speak to both spaceflight dynamics AND aircraft flight dynamics, as well as sections that speak exclusively of aircraft flight dynamics or only of spaceflight dynamics. This would make it a bit more clear to the uninitiated reader of the encyclopedia. Perhaps then a separate section for the technically and calculus-oriented reader with all the reams of equations. What do others think about the balance, and what we might do to improve the article? Cheers. N2e (talk) 21:19, 12 December 2010 (UTC)
I don't know who decided to do all this moving about, but it seems that a page which was generally about pitch yaw and rollhas been hijacked into something about aircraft dynamics.
Pitch yaw and roll apply to several things, not just aircraft. While spacecraft are now covered, what about underwater vehicles?
As a general topic, pitch yaw and roll was perfect, perhaps someone can fix that page so that it is either a db page or has a basic expanation that covers all topics form aircraft to robots?
At the moment it is a circular redirect between a couple of dynamics pages Chaosdruid (talk) 13:10, 4 September 2012 (UTC)
Yep. Whole article is uncited (much of it dubious too). One big disorganized pedantic digression. It's basically "Look at me! I know a bunch of equations! I am SOOO smart!" I gave up trying to edit flight dynamics articles for better lay understanding a long time ago. The pedants are relentless. 108.7.229.24 (talk) 18:44, 18 December 2014 (UTC)
If you search for "Yaw, pitch, and roll" you will be redirected to Aircraft principal axes while you will be redirected to Flight dynamics (fixed-wing aircraft) if you search for "Yaw, pitch and roll". Since the same search (except a comma) will bring you to two different places a merger seems appropriate. Soerfm (talk) 11:01, 2 August 2014 (UTC)
What's the difference between Flight dynamics (fixed-wing aircraft) and Aircraft flight mechanics ?Df (talk) 16:03, 17 May 2015 (UTC)
A discussion is taking place to address the redirect Attitude control (fixed-wing aircraft). The discussion will occur at Wikipedia:Redirects for discussion/Log/2020 September 30#Attitude control (fixed-wing aircraft) until a consensus is reached, and readers of this page are welcome to contribute to the discussion. Soumya-8974 talk contribs subpages 18:12, 30 September 2020 (UTC)
One of the most severe structural problems I encounter at Wikipedia on a regular basis concerns the use of sloppy redirects.
In this case, aircraft attitude redirects here, but this page is entirely too small of a box.
Sometimes that's nevertheless the right choice, if you make the situation explicit, as I have endeavoured to do with this early addition to the lead:
These are collectively known as aircraft attitude, often principally relative to the atmospheric frame in normal flight, but also relative to terrain during takeoff or landing, or when operating at low elevation. The concept of attitude is not specific to fixed-wing aircraft, but also extends to rotary aircraft such as helicopters, and dirigibles, where the flight dynamics involved in establishing and controlling attitude are entirely different.
You can argue that this doesn't belong here, but not without posting the redirect to its own proper, independent context. — MaxEnt 21:39, 23 December 2022 (UTC)
Note 1: I just noticed that the previous talk entry concerns a failed effort to address this dating back to 2020, but I'm not wading into that historic effort, as I'm fundamentally a tumbleweed editor. — MaxEnt 21:44, 23 December 2022 (UTC)
Note 2: Well, if I was making a hasty decision on my own steam, I would instantly refactor this by creating a new page reference frame (aeronautic engineering), move the vast majority of the content here that does not involve force mechanics over there (as the "main article" for said content), and punt the aircraft attitude redirect over there, too, where it would be far less of a bad fit.
I took inspiration for the proposed page name from this article title:
— MaxEnt 21:55, 23 December 2022 (UTC)
Note 3: I'm trying to run away, and not succeeding. In my dither, I realized something further: I read extensively on Wikipedia, and I've seen this problem before. It shows up all the time in biology. For example, a page I visited yesterday, via LGBT (cultural), via gay (psycho-obligate identity), was homosexuality (biological). But homosexuality covers far more than humans. So of course, the page fixates on human homosexuality, and might drift sporadically into mammalian homosexuality, or an even larger animalian frame of sexual reproduction, as appropriate. Even worse, if there's a medical aspect to the topic, the page might well become human of thing (highly medicalized).
Aircraft are an interesting technological bestiary. You end up with some of the same infernal overlap and cross-pollination. Over at armoured fighting vehicle, which I visited yesterday, there's a reminiscent yuckiness in the dividing line between IFVs and APCs. In particular, the article on self-propelled artillery does not want to quickly state that these are a subcategory of armoured fighting vehicles, because, well, the armour isn't much to shake a stick at, and they instead chose to bloat the sentence out with provisos concerning this inadequacy, which made it rambling and thus unsuitable to place earlier in the lead, which estranges it more than desired from its natural next of kin (as I see things).
So, when that axis is irredeemably clouded, what to do instead? In this instance, what strikes me is that the page title contains the word "dynamics". My main subject of interest right now is control theory, as applied to human systems (like wrangling marbles with chopsticks), meaning "control" in the sense of civilizational homeostasis.
The frame and the axes are not dynamic, and all the meat on those bones only delays this article from addressing its own dynamic concerns. So I'm left amplifying my original page split suggestion above. — MaxEnt 22:35, 23 December 2022 (UTC)
The result of the move request was: moved. (closed by non-admin page mover) 2pou (talk) 07:30, 14 January 2023 (UTC)
– WP:NATURAL. The current titles, particularly the aircraft one, are unwieldy and plain ugly. "Aircraft flight dynamics" is a plain English, broadly understandable term, also used in real life [1]. The proposed titles would also bring consistency with Aircraft flight mechanics, Aircraft flight control system, Spacecraft propulsion, Spacecraft attitude control etc. I don't think we need overprecise "fixed-wing" in the title, since helicopter flight controls is also at a logical title, and a hatnote could clarify the scope anyway. No such user (talk) 09:17, 6 January 2023 (UTC)