Kites Capable of Flying Off-wind?
  • Hi folks -

    For some time now, I have been searching the discussions to glean information on kite flying characteristics and capabilities. This blog is a Treasure Chest of information, and knowledge abounds here! The discussions led me to my first purchase for a strong, stable, LOW wind KAP rig platform: my Fled. A terrific choice for where I live (South Carolina) and for my generally confined spaces. But now I need to get my next kite, and it has to do something speacial in addition to being a strong, stable, relatively high angle flyer: IT SHOULD BE CAPABLE OF FLYING IN AN OFF-WIND DIRECTION, somewhat like a sailboat that tacks.

    Like many folks in these discussions, I have walked along a shore with the wind blowing parallel to the water's edge, and there is something like an old fort that I want to shoot from an over-the-water point of view. The Nighthawk from fishingkites.co.nz is a delta that can do that to the extreme - like 40 degrees off-wind.

    So here is my discussion point: Which kites are stable enough for KAP and can be adjusted at times to fly at something of an angle to the wind direction by adjusting balance, weight, bridle or ... ? Does anyone have experience or success trying this challenge in moderate wind, Bft 3 to 5 ... or more...or less?

    Thanks for any comments - Phil
  • I've flown the Flow Form 16 off wind by tweaking the bridles and moving the tail to the side, but nothing like 40 degrees.
  • Phil,

    While not that common with Kapers, tacking is commonly used with fishing kites to place long lines over selected reefs for fishing.

    A Skyhook Kite Sail is attached to the line below the kite to direct (pull) the kite line up wind.

    See link and information here.

    Enjoy,

    WW
  • anyone played with trimming kite position using RC? for instance moving the tail or even adjusting bridle while maintaining the simplicity of the single line operation?
  • The instructions for the Paul's Fishing Kite suggest that you can "tie a screwed up plastic shopping bag" to a line attached to the end of a wing to pull it to one side. Keep meaning to try this but have not needed to since I got the kite.

    Martin
  • The fishing kite people are the experts. It took me a while to figure out why they were selling extra bits of fabric that doesn't provide lift.
  • Broox - what kind of angle have you been able to maintain - say, 15 degress or so?

    That would actually be pretty good, considering the lower flying angle flowforms have with the gound -- thus you could of course be over the water significantly more than a high angle kite, even a little off-wind, yes?

    Also, could this be done with the Levitation delta - somehow adjusted for slightly lower angle AND off-wind? Roks too, maybe?
  • Phil, I haven't done much experimentation with this. Yes, probably 15 degrees is doable with the Flow Form.

    There's not much to adjust on the Levitation delta, for either parameter.
  • Wow. For me, this is a whole new way of thinking about kites. Given that many of the sites I photograph are coastal, this technique could be extremely useful. Something new to practice.

    I've also been thinking quite a bit about attempting a kite train. The SkyHook strikes me as something like a simple kite train, but one that can be used to alter the direction that the kite flies. It also seems that the SkyHook can be flown under just about any kind of kite. Am I reading this correctly? Thanks to AerialLensGuy for starting a very interesting thread, and thanks to all those who have written in with interesting replies. Thread bookmarked.

    Regards,
    Nathan
  • theonecalledtom
    anyone played with trimming kite position using RC? for instance moving the tail or even adjusting bridle while maintaining the simplicity of the single line operation?


    I actually used to have a RC hang glider that would launch like a kite, and when you reached altitude, you'd hit a button which would release the glider from the line. The line had a little pod with a parachute, so you could easily track it down. To steer the glider, there was a ballast that would swing left or right in response to your input on the controller.

    The glider was really nothing more than a small delta kite with ballast on the bottom. So I'd be willing to bet that what you're questioning is very possible.
  • Thanks for all the input so far - this really helps! The idea of RC is really interesting but the dynamic capability might not be needed. By that I mean if you are aware of the challenge/wind direction at the time of launch, it may not be necessary to change anything once you are up and off-wind...unless of course the wind changes during the flight. Still, an awesome idea that shows "thinking outside the box."

    Has anyone seen a video or photo - or even an illustration - of how Paul's Skyhook can alter the position of a kite? The fishingkites.co.nz site refers to this, as well as the main use of the Skyhook (light wind aid), but I cannot find anything that shows how it works. Anybody seen one work?

    Here is a crazy question - showing off my ignorance now - would the Skyhook work to set a 6 foot Rokkaku off-wind in conjunction with setting the Rok's AOA for a lower angle relative to the ground. I would not want to lose the Rok's lift, but the normal flying almost overhead would of course miss the whole point (of tacking out over the water or other feature). Sorry if that is confusing.

    Main question for now is, has anyone seen the Skyhook in action?
  • Interesting discussion. The amount of trim required to achieve a desired tack angle is dependent on the wind speed. A bridle setting or an unbalanced drag applied to one side of the kite that results 15 degrees of tack at a given wind speed, may result in undesired performance (i.e. looping or overflying to the left or right) in higher wind speeds or gusty conditions, so adjustments should be made carefully in small increments until the desired tack is achieved.

    Having radio control of the trim would be great. Another potential approach would be to add some type of adjustable, limited authority spoiler (or aileron or rudder) to the kite itself. These types of surfaces may require less energy to control than would be required to change the bridle position itself.
  • Phil, if I may nitpick: I think you mean a lower 'string angle', not 'angle of attack', which is the angle of the kite's surface to the wind.

    My experiment with the Flow Form 16 consisted of tying a knot in one of the side bridle lines to shorten it an inch or so, and perhaps moving the fuzzy tail to the outside corner (can't remember that part).

    Here's the picture I was after; as you can see, not much offset, but enough to see some of the side of the ship:

    Spirit of 98
  • Thanks, Broox - of course you are correct - sorry. By the way, FANTASTIC picture of the ship! Maybe the Flowform has potential for this sideward technique after all.

    I still cannot find any photos of the Skyhook used for tacking out, but if it pulls strongly, couldn't it be located somewhere below the camera rig? The progression on the line from the ground would be Kite flyer (or stake) then Skyhook then camera rig then kite. If the cross wind vector from the Skyhook were strong enough, it would produce the tack angle and then the line from it to the kite would be with the wind. Any thoughts?

    Sure wish there were some skyhook-in-action photos out there.
  • I would recommend a rokkaku for flying "off wind". After all, these kites are used for kitefights in Japan between two teams on both sides of a river.
    After some bridle adjustments I have flown a rokkaku approx. 15 degrees "off wind". Be careful though, you need a gentle breeze, a windgust will put you're kite in a slow but deep dive in the "off wind" direction. (In you're case the ocean..)
  • Thanks guys - I have written to Paul's Fishing Kites to inquire about the capabilities of their kites and sails, and maybe some practical videos or photos.

    The Rokkaku sounds great, but the requirement of a gentle breeze kind of takes it out -- I need this to work in moderate wind of say 10 to 20+ mph. Perhaps if an intermediate kite were set up down the line to pull it out at a sideward angle, and the Rok above that (as in discussion above)? Maybe do-able?

    Your suggestions are really appreciated here.
  • This is probably a very risky solution, but what about the option of a two-line stunt kite? I've attached micro camcorders to mine with zero effect on the flight properties. Of course your average point n' shoot camera will be considerably heavier, but with the right combination of kite and wind, you might be able to sneak the camera into position?
  • Any idea how much de-centering you need in a rokkaku bridle to make it go off the wind like this?

    I'm kinda laughing as I write this. I've been absolutely paranoid about centering the bridle on my rokkaku, and I fought my G-Kites Dopero for several months because it kept flying off the wind every time I went out. I finally traced it to a number of asymmetries in the sail, mostly in pockets whose stitching had started to go. An afternoon spent with needle and thread fixed most of this. I found it to be extremely sensitive to symmetry. So I was extremely careful to try to get it as symmetric as possible. I can see the utility in having a kite that can predictably fly off the wind by a good margin, but it's funny how much time I spent trying to counteract exactly what's being asked for!

    But if the offset numbers aren't too wild or too unpredictable, I wonder if I could mark the bridle on my rokkaku for left-center-right and dial an offset on the ground prior to launch. There's a subject I've never been able to photograph for just the reasons stated. I wouldn't need a huge offset, maybe 10 degrees to the right. But without an offset the only way to get over the subject is with close to 2000' of line and a low-angle kite. Compare that to a normal 300' line length on an offset kite, and you can see the attraction.

    10-20mph wind sounds like healthy conditions for a Flow Form. Brooks, I think I'd like to try the knot in the bridle line and offsetting the tail trick. It's howling tradewinds right now, so it's good conditions to test in. Hey, maybe I could fly a FF8 and a FF16 from the same hand and not risk a collision!

    Tom
  • Wow, Benedict, thanks for the ideas. In my vast LACK of experience, would it work at all to put fuzzy tails on one side of a rokkaku? Seems like it would tack it a little to the side, perhaps without dancing all over. I do want to be able to anchor whatever kite we come up with, not fight it.
    a rel="nofollow" href="">

    Kind of like this? Can someone give it a try?
  • I actually like the PFK Skyhook arrangement. I have flow kites (mostly deltas or ROKs) with adjustments to the wings or bridles to introduce asymmetrical flight conditions to either correct a poor flying characteristic or to move a kite off the wind center line. If the wind changes speeds this can throw the balanced flight off and cause the kite to dive. The Skyhook arrangement - you can keep a stable kite (that will stay stable under a wide wind range) and let the Skyhook do the work to move the kite line off the wind center line.
  • No chance to test this here right now. The tradewinds did come back, and now we're getting 40+MPH gusts through town. Too fast for me. Aaaah, to have a PFK...

    Tom
  • Wind Watcher, what were you able to accomplish on the Rok before it would become unstable? Also, how low and what orientation have you tried the Skyhook. I did get an email reply from PFK, but it was not specific on the tacking use of the Skyhook, and had no references other than offering an instructional DVD sold on their site. They offered the (about $12 + $12 shipping USD) DVD about kite fishing that might explain various ways to configure the Skyhook.

    It is very cool that you have done this -- any notes or pictures or memories you could share?
  • Ahh! I just received another email from Paul's:

    "The skyhook is like a jib on a yacht. It provides extra power in light winds and provides the fishing power needed when tacking the kite.
    You can tack the kite and the skyhook, or just the kite. Tacking just the skyhook does not do much at all.
    The kite MUST be flown with the skyhook, the skyhook cannot be flown on its own without the kite."

    So, there you go. The Skyhook really needs to be within a few feet of the kite and it cannot power the kite off-wind by itself. Hmmmm.

    So, I guess it is going to be bridle adjustment and/or tails, depending on the lifter.
  • Let me rephrase the original question, then. Can a kite other than a PFK Nighthawk delta be flown stably off-wind by altering bridling or by adding off center weights or tails? Can someone with moderate wind give it a go and share observations?

    I did roughly put components of a Rok through the online NASA Foilsim III graphic calculatior using zero/thin airfoils ("eliptical" in program) and varing the angles for the main panels at about 15mph (It is cool. see at www.grc.nasa.gov/WWW/K-12/airplane/foil3.html). If I did it right it looks like -- when tacking -- one side of the rok gets both drag and lift and the other gets almost all drag if a certain off-wind angle is exceeded. This interactive online graphing program is for wings (airfoil, eliptical or whatever), not kites, so who knows.

    There has to be an answer in addition to using a Nighthawk.
  • I'm planning to get out Saturday morning and Sunday afternoon this weekend. I'll give it a go with both a rokkaku and a Flow Form 16, if I can find conditions to play in.

    Tom
  • Really looking forward to that - thank you very much in advance.

    Although this is a serious subject, I thought of something humorous in case you wanted to try tails but had none -- wiffle balls! Ha.

    Photobucket

    Phil
  • The first kite I build (a Conyne) wasn
  • Hello, FlyingFool - Thanks for bringing the DC into the conversation.

    I had earlier considered a 9 to 11 ft delta conyne, but became concerned with two things, although I have zero experience with these. (1) I read they have a strong tendancy to dive at times, particularly after going too far overhead. (2) It also seems, by looking at some comments -- paticularly Mike LeDuc's video database set on Flickr -- they do not pull very hard relative to other kites in moderate wind. I DO like how they can hang in a lull, however. I have no clue if that sounds correct to you. Please comment if you have seen it behave differently.

    In any case, thank you for mentioning the off-wind behavior of the DC you have. Did you find exactly what initially threw yours off balance? I have heard it can be a problem with either the bridle or the lay of the fabric not being symmetrical.

    Either way, I am leaning toward the 7 foot Rokkaku or a Flowform 16 unless someone finds a good stable wind tack is just not possible. If that occurs, then the DC could be an answer. One thing for certain in my region is that wind is often variable (e.g., 12-15mph maybe with small gusts), not super steady. I hope I am not asking the impossible (improbable?).
  • I know these weren't directed toward me, but my preferred kite is the 10ft. Alpine DC from Into The Wind, so I'll chime in...

    (1) I read they have a strong tendancy to dive at times, particularly after going too far overhead.


    Mine has NEVER dived, though it definitely can overfly. This is easily fixed by adjusting the position of the pigtail on the bridle; move it back, the kite doesn't soar as high. I find that flying with 2 fuzzy tails on the inner attachment points in conjunction with small (.25 inch) pigtail adjustments allows me to fine tune the angle at which it flies.

    (2) It also seems, by looking at some comments -- paticularly Mike LeDuc's video database set on Flickr -- they do not pull very hard relative to other kites in moderate wind. I DO like how they can hang in a lull, however. I have no clue if that sounds correct to you. Please comment if you have seen it behave differently.


    I prefer to fly mine when the wind forecast is 10-15MPH, and I gotta say, it has no problems whatsoever lifting my HoBEAK rig and Canon Powershot A590. It doesn't pull so hard that you have to wrestle with it, but it takes my rig up with ease. And yeah, when the wind dies down, it gently glides, it doesn't drop like a brick.

    I should add too, as this has just occurred to me, but back to the original topic... I have actually found that my DC does have a tendency to fly to the side if one of the leading edge spars is NOT pushed all the way to the front. It's never been off-center enough that I feared it would dive, but it was noticeably off-center. I don't know if that's a common trait with DC's or delta-shaped kites in general, but one suggestion that's often given to correct off-center flight with DC's is to make sure the spars are pushed all the way front.
  • Phil,
    Keep in mind that the Delta Conyne I videoed has a 7.5 ft wing span, so it's pull will naturally be less than that of a larger kite.

    Mike
  • The kite I mentioned was a Conyne, not a DC. It never did overfly because it doesn
  • fnf - I may have it backwards but I thought fairly recent discussion here stated that the wing spars were to be pushed to the tips of the wings. To allow
    flex at the front....someone please correct if I've got it wrong.

    FF -won't cotton " breathe " too much, be too permeable, not " hold " the wind....?

    PS - check under " Kites - delta wing flutter ". Just looked back.

    Brooks: Thanks for the link tips. Will try next time. Too early on a Sunday morning....
  • @ Paul: It's a very tight woven, thick cotton. As I intend to use it from 5 Beaufort up I think a little 'breath' won't be a problem. I figure what was good enough for George Lawrence should do me fine too. I'm not sure yet I'll ever put a camera on the string though, it'll have to prove itself first.
  • Hi all,

    Great subject!

    I haven't read all comments here, but I once used my 8' Rokkaku to KAP a specific subject. The wind and the launch site were not in my favour so the only way I could get my kite where I wanted it was either wait for better conditions or make it getting there by making the the upper bridle asymmetrical. Worked just fine.

    The only person I've ever seen using the Skyhook is Gerrit Bart. He used it together with a PFK delta. This way he shot all material for his 1st KAP book over his island Terschelling. Indeed, it only adds lifting power. It cannot be tuned to get the kite somewhere else.

    You can see the PFK delta/Skyhook in action in this page: Scroll down halfways. There are two pics.

    Ramon
  • As far as I can tell tacking off wind can be controlled by having an asymmetric bridle, creating drag on one wing, adding weight to one wing, etc.

    As you get further off wind you loose lifting power and tension. I think this is where people argue that the Skyhook becomes useful for tacking. Keeps your line useful for lifting and your kite out of the water.
  • Paul Costelloe - You might be right about that. I don't remember for sure, but I always make sure to move the spars all the way forward, and that guarantees straight flight for me. At least with the Alpine DC, the spars are slid in from the wing tips. So I find it's easier to find symmetry by sliding the spars all the way forward than trying to match it at the wing tips.
  • @ fnffishcore: I don't have a DC myself but I'm pretty sure the spars should go all the way BACK, like in a delta. There's no need to match anything at the wing-tips, if the kite is symmetrical as it's supposed to be it'll match itself.
  • Correct. Push the spars all the way to the wingtips. There needs to be flexibility at the nose of the kite.

    Regarding cotton, I've read that open weave can provide stability. I've used patterned bedsheets for kites many times -- they fly great, and I recall thinking at the time that indeed they fly better than those made with nylon. D-C or Conyne would both be good in cotton.

    The papagallo fighting kite of Rio de Janeiro is made of a cotton so open it looks like mesh. Flies great!
  • I got out yesterday and flew my rokkaku, but it wasn't a great location for testing something that might cause a kite to go down. (I was flying over private property, and there were protected habitats underneath my kite and rig.) Going out again today in about half an hour, and it looks like I should have at least one spot I can stop and fly a pair of kites. One will be unmodified, one will be modified. I'll try to catch stills and video of the two in action. If fortune smiles, photos to come.

    Tom

    P.S. The KAP flight yesterday is my first KAP since WWKW 2010, and my first since getting cleared of the pneumonia that wreaked havoc on my WWKW this year. MAN am I out of shape!! I never really thought of KAP as a conditioning sport, but in truth it is. My winding arm is zonked. But the pictures looked good.
  • I got out and gave this a try. The results are good!

    Offset Flying

    The first test used a Flow Form 8 as the baseline kite, and a Flow Form 16 as the test kite. I didn't try any tail offsets, but I took up as much as 2.5" of bridle on one side of the Flow Form 16 and it still flew almost right on top of the Flow Form 8. It's nice to see how little the orientation of the FF16 depends on bridle symmetry. (I make sure mine is symmetric, anyway.) I think a tail offset would change this, but it's not something I've tested.

    Next I put the FF16 up as the baseline kite and tried using Ramon's trick on my rokkaku. Before doing offsets I flew it in "normal" mode and found it flew just slightly to the right of the FF16. Then I did a 2" offset to the left of center on the upper bridle Y, then a 2" offset to the right of center on the upper bridle Y. Those two pictures are shown above. In all cases all kites were flying on 200' of line. The dimensions of the rokkaku are 5'x6'. Popping all this into CAD, I got an offset of 20.7 degrees to the left, and 24.8 degrees to the right. I'm taking this as a more or less 20 degree offset for a 2" change on the bridle.

    I haven't had a chance to test this in any sort of rigorous way, or to get any kind of scaling for how much offset on the bridle gives you how much offset on the sky. But I'd say the rokkaku falls solidly into the category of kites that can fly off the wind.

    Tom
  • Very nice work,Tom! This knowledge should come in handy down the road.
  • Tom - That is simply FANTASTIC! Much praise and commendation for your efforts to set this up, especially after being ill, waiting for tradewinds to die down, etc. I'm willing to bet that everyone -- not just me -- appreciates this. It appears this is new territory which I know will be useful in situations related to this topic. Great job!

    I'm sure a well known North Carolina kite maker does not mind me sharing his opinion that a Rokkaku is a "Swiss Army Knife" of KAP kites. This evidence certainly appears to shape up in that direction.
  • A South African kite company that claims to be able to get 70 degrees off wind either direction:

    http://www.mullerskitefishing.com/how.htm

    They don't really describe the tacking adjustment and I suppose the kite must fly quite low if it's 70 degrees off wind, but it would be interesting to hear more details.
  • @Benedict: Great results so far, Tom!

    An option you might want to try is to shorten BOTH bridles on ONE side. It should translate the Rok to that side. I tried this myself Saturday, but got no clear results (week wind, bad location, no reference kite). After all that's how you would steer the kite if it had two lines... This way of trimming might give less reason for looping than changing just one bridle (less asymmetry)? At least, thats how I would feel about it if I was a kite ;-)

    I'm just guessing, of course... Thank you for your field tests!
  • Tgran, thats an interesting link to the fishing kite, as you say not enough details even as a sales website. I would guess that its not height but distance down wind thats important with kite fishing. Read low angle. As an occasional surf casting fisherman, 300m plus is impressive. To be able to control a kite that far from directly down wind could also be useful at times, 70 degrees either side seems a lot? Could a kite maintain enough lift to KAP at those angles?
  • The "Muller's Seagull Kite" is interesting, but you are right about the website - needs some work for sure.

    I DID find a fellow's comment on the kite with some very revealing photos, however. It appears from the first photo that a line along the side of this kite may have something to do with its tacking setup. (See the photos at www.sealine.co.za/view_topic.php?id=34025&forum_id=82). Still a lot of unknowns of course.

    This is getting even more interesting.
  • Arrrr! It looks like it tackes to the side as the flier pulls the line. It does not stay there as as soon as you release the fishing line the kite moves back to the down wind position. So its a bit like a stunt kite, tacking from side to side but not sitting still enough to KAP????
  • If found a tip we might use IF we ever find out how to 'tack' these kiwi delta's ;-)

    "Kitefishers can really benefit from practising tacking in good clear air in a park. By doing this you can wind up with a variety of tack ropes, tested and labelled for different tacks and wind speeds. This can make life so much easier when you get to the beach. You simply put the kite up with the appropriate tacking rope for the conditions and away you go!"

    Edit: @Puffin: I think the tacking line goes from the wingtip to an attachment point a bit lower on the line, and that you have to attach something to to that line to cause drag? I'll experiment with this on my PFK when weather and time allow...
  • Came across this on Youtube from PFK. Video shows kite fishing up close. Near the end of the video it shows a Nighthawk kite with a weight attached to the right wing tip to tack the kite off the wind center line. Simple and easy. I have done similar tricks with my PFK deltas. Works well.

    WW
  • Thanks WW - that is really cool. Man, the fishermen can get into some intense conditions. Admirable.

    After seeing Tom's great success, I was definately intrigued that to set up a Rok the kiteflyer could simply mark the bridle for the flight needed and quickly set up for tack that way. Then, I got to wondering if there were other ways as well to do the same sort of thing with a quick setup, and came up with a possibly goofy idea of adding 2 lose dangling lines where the spars cross at the center (tied to center on one end only until needed) and then securing these only as needed on either side to set more of bow/bend into the spars on the right or the left.

    Photobucket

    While kites are more dependent on drag and the way wind is spilled from he sails, maybe this would also work to shift the kite off wind. Ahhh, more experiments. I know, maybe thinking TOO far outside of the box.

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