Talk:Spin (flight)
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[edit] Misc Discussion
I am about half way through my PPL (Exercise 18) and was aware of spinning, but no where near as much as I was going to be after my first lesson on Saturday 10 January 2004.
I am learning at Chester Flying School, but they do not have planes you can spin in. For this I went to Barton Aerodrome and the Lancashire Flying School - for a lesson with Bob Knight. He chose the plane carefully, a Grob G115.
I had tried to prepare myself for what was to come (remember your build up to the first stall and the subsequent "what was all that about"?), but was blown away by the sensations when we entered the first spin. I knew he had used full left rudder, but would not have wanted to bet more than a fiver as to what direction we were actually spinning - irrespective of the odds. I am sure he was worried I was going to throw up in his nice plane, but it was my head that struggled to cope, not my stomach. My first reaction was what on earth am I doing here on a Saturday afternoon spending good money on something the CAA don't consider necessary. My follow up, more considered thought, was that I would have no chance of coping with this without hands on experience and instruction. I honestly believe they should either rip out exercise 11 from the books or include it properly, with training.
We did three more spins, with me in full control of the third. For the fourth, I used too little rudder and put it into a spiral dive from which Bob (who was not impressed) recovered.
I came away with a combination of a renewed respect for this pass time I have taken up and a determination that I want to "master" spinning, so have booked myself in for another lesson this Friday, 16 January.
David Savage david@pacificchartered.com
Re: Edits by bannaramabingbong. As discussed on his talk page, I'm not sure that some of the changes made are an improvement. For example calling a spin an 'aggravated uncoordinated' stall rather than a 'special case' of stall, to my mind adds no worthwhile information to the article, in fact, it makes it more impenetrable by the layman. This is not a flight manual. We need to be factually correct but without bringing in technical jargon that obscures the readability. There are other similar changes I have a slight problem with. In addition, some of the corrections for "grammer" [sic] introduce numerous spelling and grammar errors of their own. We need to discuss the specific issues that people may have with the article and reach a consensus, not enter into an edit war, which is counterproductive. Graham 23:48, 11 Oct 2004 (UTC)
I've overhauled the spelling (possibly just typos) and a little grammar/style. I've added a link to sailplane. My only query is the type of English – U.K. or U.S. – intended by the original author. The Wikipedia rule is to stick to the original intent, but there's a bit of a mixture here. I started changing it (for example &slquo;practise&srquo; rather than &slquo;practise&@srquo; as a verb), but then noticed lots of &slquo;center&srquo;s, etc., so thought that I'd better stop. Any advice? Mel Etitis (Μελ Ετητης) 15:27, 4 Feb 2005 (UTC)
Be bold, make a decission and stick to it. Aberglas 01:25, 6 Feb 2005 (UTC) aberglas
- As I created the article initially, I can tell you I use British English. But there have been many, many edits since. Graham 05:02, 29 January 2006 (UTC)
I see that User:Aberglas has removed one of my additions; I suspected that I might have misunderstood the point being made — the problem is that, as it stands, that passage reads rather obscurely. Could we discuss it so that it can be made clear? Mel Etitis (Μελ Ετητης) 10:24, 5 Feb 2005 (UTC)
If you are talking about spin-resistent airplanes then there are some aircraft that simply will not spin (with normal CoG). Eg. ASK 21 glider. So it is more than holding control positions. But in any case this is covered a few paragraphs down, so there is no need to repeat it where it was. Aberglas 01:21, 6 Feb 2005 (UTC)aberglas
Sorry, my fault — I didn't say which edit I was talking about. It's in the fifth paragraph of the first section: “This is largely achieved by ...”. As it stands it's unclear what the ‘this’ starting the second sentence refers to, and I wanted to make it clearer. The term ‘manoeuver’ was apparently wrong, but can you think of some other way to do what I was trying to do? Mel Etitis (Μελ Ετητης) 10:29, 6 Feb 2005 (UTC)
[[User:Aberglas|Aberglas], that's perfect — exactly what I had in mind but couldn't work out how to do. Mel Etitis (Μελ Ετητης) 10:14, 7 Feb 2005 (UTC)
I'm curious about the reference to spinning through cloud - personal experience? :-) Brendano 22:33, 31 Mar 2005 (UTC)
Just reading the first few sentences, I find a conflict in the definition of a spin already. The way I've learned about spins, is that they are NOT stable to an airplane, and with controls neutral, an airplane should recover from it eventually on its own. The only dangerous situation where an airplane will NOT recover on its own, is a spiral, where there is no stall, but the plane is essentially in a steep decending turn, with speed increasing rapidly. To keep an airplane in a spin, the pilot needs to hold the rudder all the way left/right, and the elevator up all the way. Am I wrong?
Ted Vailas --Tvailas 20:25, 15 July 2006 (UTC)
- I believe what you're describing is the Beggs-Mueller spin recovery technique, which I don't see anywhere on Wikipedia...I may have to incorporate it into the article sometime soon. Essentially, you let go of the controls, and the plane does in fact recover itself from the spin. However, as I understand it, all airplanes have different spin characteristics, so some can easily recover from spins, while others simply don't have the control authority. Or, a given plane technically can recover, but the altitude that it takes to effect the recovery is more than you'd ever have flying the plane, etc. It just depends on the plane and the situation. Yvh11a 06:47, 17 July 2006 (UTC)
[edit] Aerodynamics of a Spin
Is it always true that both wings will be stalled? I was always taught that both wings are stalled, one wing stalled more than the other. I had a designated examiner insist that an airplane can spin with one wing stalled and one wing flying. Wouldn't this result in a roll/spiral. (Imagine one wing being completely torn off.) Comments?
- I don't think it's very useful to talk about degrees of stalling - once stalled, the wing is stalled. You can't really say one wing is "more stalled than the other", neither are producing any usable lift. This reflects the lift curve for an aerofoil which basically drops off almost vertically beyond the stall angle. I suppose you could say that one is more beyond the stall AoA than the other, but it makes no difference to the lift produced - there is none. I'm not sure about the case of one wing stalled and the other not. I guess there is a very small range of AoA and yawing that might produce this condition, but as soon as the stalled wing drops, the aircraft will enter a very different flight envelope from what it was in just prior, which could be a spin or a spiral dive... depends on the exact conditions and the aircraft's characteristics I suppose. Graham 04:59, 29 January 2006 (UTC)
It seems that people are confused on the topic of a spin. It is true that in a spin one wing is more stalled than the other hence increased drag and autorotation. For reference, refer to AC 61-67C. You can find it at: http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/A2FDF912342E575786256CA20061E343?OpenDocument
- That's a very useful reference, the article should probably link it. However, you appear to be wrong that it discusses "one wing stalled more than the other" - I couldn't find any passage that could be interpreted as meaning this, though admittedly I did speed-read it rather than go through it meticulously. When I get more time I'll read it thoroughly. However, just from physical principles the description "one stalled more than the other" doesn't really mean anything in my view. At the onset of the spin there is an asymmetric stall condition for sure, but by the time it is fully developed both wings are thoroughly stalled. The spin autorotation is sustained by the airflow over the machine in this stalled state as a whole - much as a sycamore seed will spin down to earth when it falls. If you think of the lift curve of an aircraft as a right-angled triangle shape with the hypotenuse the linear lift and the steep drop as beyond the stall, and the drag curve as a square law with an almost vertical slope coinciding with the stall, beyond the stall point the L/D ratio is going to be very close to zero for a wide range of AoA. It doesn't matter whether the L/D ratio is 0.01 or 0.001 (which might conceivably be the case for one wing and the other in a spin), it's not going to a) hold up the plane and b) create enough difference to sustain the spin. This is not a 10:1 difference, it's about a 0.0009% difference, since such a tiny difference in lift is overwhelmed by other forces, like gravity and drag. The falling aircraft is not a naked pair of (stalled) wings, it is the whole thing, and the rotation is caused by airflow around all of it, not just the wings. Graham 05:02, 21 February 2006 (UTC)
[edit] Spins Mandatory
Removed "Spins are huge fun, and should be mandatory for all pilots taking their ppl." for npov.
[edit] 'Inappropriate tone' template added
Today I've added this template to the Recovery section of the Spin (flight) article. The writing style used in this section -- and in a few other places in the article -- seems to this non-aviator to be a mixture of aviation lesson terms, and/or minor vandalism; or perhaps overly-exuberant flight jargon ("chipmunk erect normal"??)
Also, I've moved the third paragraph of the section Aircraft design to here. It also needs editing for style and meaning, see below.
A spin is the aircraft trying to (or very nearly) reach a normal state of equillibrium, if she reaches such a state, then it will take "effort" to get her out again, nothing to be scared of, but you need time, and time = altitude = another try again on another day., spins are fun, try them, they're a wonderfully normal aspect of aewrodynamics that have been wholly misprepresented and misunderstood.
Cheers, Madmagic 01:26, 9 March 2006 (UTC)
[edit] tomahawks are stil certified for spins!
in the article I noticed that it said the certification was removed from the piper tomahawk, preventing it from intentional spins. this is simply untrue, I own one and spin it regularly. I have never heard of the faa or piper removing the spin certification.
[edit] Cleanup
I've redone most of this article. It still needs some work; in particular, it needs to be wikified, and the last two sections (the salesman story and "Aircraft Design") are of dubious value. The sections may also need to be reordered. Above all, please take care to avoid colloquial style, and remember your audience. Wikipedia is not a flight training manual, and this is no place for hangar talk. -- Captaindan 04:19, 10 October 2006 (UTC)
[edit] Sample Video
I don't know anything about this phenomenon (I can't even drive!) but I stumbled across this video [1] whilst browsing the web for something entirely different. Maybe you guys can work it into the article somehow? -- Jasabella 11:39, 10 October 2006 (UTC)
[edit] diagram
I don't understand what this diagram is trying to show. The axes are not labelled, although presumably they are meant to be angle of attack (horizontal) and coefficient of lift or drag (vertical). Also, the "High Wing" and "Low Wing" labels are ambiguous. Do they refer to the pitch of the aircraft or to each wing separately? Coefficient is consistently misspelled.
I don't think that a spin is something that can be easily summarised in one diagram. The whole process from incipient to recovery is described by an angle of attack which is varying in time and along the length of the wings. If someone feels brave, this could perhaps be visualised with a similar animated diagram with an aircraft model superimposed showing how the angle of attack varies in time. The two wings could be depicted with separate colours.
Regardless, I'm going to re-jig this diagram in SVG... --BWDuncan 12:16, 9 November 2006 (UTC)
[edit] Howto
I added the Howto tag, in particular due to the detailed spin recovery procedure. Wikipedia is not a flight training manual. If someone wants to move this somewhere else, please do. Otherwise I will delete that section, unless someone makes a reasoned argument here. I put a generic technical explanation in the next section to cover this. Dhaluza 02:43, 5 January 2007 (UTC)
- I agree that the list is too detailed for Wikipedia, but I belive some of the info is still relevant. I've condensed the list into readable paragraphs which I hope are just technical enough. I left the howto tag because I still have doubts about the last paragraph--you can't in my opinion have a page on spins without talking about how to get out of them, but no matter how you word it it still reads like a list. I leave the ultimate keep/remove decision up to Dhaluza and the community. Yvh11a (Talk • Contribs) 05:26, 9 January 2007 (UTC)
