Kites Capable of Flying Off-wind?
  • I don't think you're too far outside the box. I figure if you come up with an idea, can demonstrate that it works and that it creates stable flying conditions for the kite, it's fair game. Every new tool or technique we can stash away in our KAP bags or our KAP brains is a new tool we can employ in the field when conditions warrant it. It makes KAP more versatile. Fair game.

    For my part, I'd like to play with offsetting the FF16's tail as Brooks did, and I'd like a good two hour session with my rokkaku to try to calibrate a scale of bridle offsets and sky offsets. I get the feeling it won't necessarily translate to other rokkakus unless they're bridled identically to mine. But if that means I can stick a little laminated card in my bag with a table of offsets, that's pretty darned sweet. This weekend is looking good for more tests.

    There are two flying conditions here where having this available would be a boon: A common coastal condition is to have the wind blowing straight down the coast, especially between Kiholo Bay and Kua Bay. Being able to offset the camera out over the water and aim back toward shore makes for a whole set of nice photographs I'd like to make. The second is my as yet unrealized dream of flying a camera over the active vent in the Halemaumau Crater on Kilauea. With even a 15 degree offset, it can be done on 1000' of line, and with some finagling and a little more offset it can happen well under 500' of altitude. Without offsets the prevailing winds make it so the KAPer needs to be about 2500' upwind. I've got 3000' of line available, but this is not my idea of a good time. Not that I have permission to do this yet, but I'd hate for that to come through and be unable to take advantage of it.

    So thanks again for starting this thread and exploring well outside the box. Seriously cool stuff.

    Tom
  • Really looking forward to hearing what happens on the Flowform.

    Here is a dumb question - Why do you need permission regarding the kite at Halemaumau Crater? I am guessing tour helicopter safety???

    Anyway, I am really now leaning toward the Rokkaku, but waiting to see if you can go even further off-wind. Thanks for all your input -- it is an education.
  • Sorry, I didn't get to fly over the weekend. Combination of lousy winds and lots of laundry and house cleaning to be done. Here's hoping for later in the week.

    Halemaumau Crater is inside Hawaii Volcanoes National Park. As far as I've been able to tell, the right to fly kites in a national park is entirely at the discretion of the park's director. The director at Volcanoes has told me I am not to fly kites in the park. But I've had a couple of leads on getting permission to fly since then. Unfortunately nothing solid enough to fly with, so to speak. I get the feeling it's partly helicopter safety, and partly that if a kite goes down it can't be retrieved. So it becomes litter. Big fines for littering in the national parks.

    The only other national park on the island is Puuhonua o Honaunau National Historical Park, or Place of Refuge. I asked there, too, and the answer is also no. In this case the reason is a lot more direct: the entire park is a historically sensitive site. Damage done to structures in the park is permanent, and the structures are irreplaceable. So this makes perfect sense to me. Of course I found you could fly from a boat dock about a hundred yards from the park, get a great angle on the park itself, and never put kite or rig over park land at all. So no risk to the structures and you can still get oblique angles on it. The one time I tried, though, the wind was too light to pull it off. Ah well.

    I'll let you know as soon as I can do the tail tests with the Flow Form, and as soon as I find the limits of how far the rokkaku can go off-wind.

    Tom
  • I wonder if kite mods are really the way to go? Introducing asymmetry into the kite or tail arrangement will certainly make it fly to one side, but it will also push it closer to the edge of it's stable envelope, degrading it's performance and making it more likely to fall off the wind and power dive down.

    To my simple mind, the only right way to do this for KAP is to deflect the line with a sail part way down the line as described earlier. At least doing this does nothing to degrade the performance, and more importantly, the recovery capacity of the kite. It dog-legs the line in the sky but the kite flies and feels the wind unencumbered.

    Simon
  • I don't think any of these techniques come for free. It's kind of like driving a car. You've got X amount of acceleration the car can take before the tires lose traction. You can spend that cornering, or braking, or accelerating, or some combination of the three. But everything you do to the car reduces its safe window of operation. Push beyond that and you're in a skid.

    I agree that deflecting a kite by making it asymmetric carries with it penalties. While I was still having issues with my Dopero, I often saw it 75-80 degrees off the wind. It had practically no surplus lift, and I doubt it would've survived a change in wind direction. I'd like to test the rokkaku and the Flow Form and see how far off the wind I can push them before they simply won't fly any more. It lets me know how wide that envelope actually is. My guess is the Flow Form won't tolerate being pushed more than 40-45 degrees off wind, and the rokkaku will take up to about 70-75 degrees. Which tells me 10 degrees may not be too bad for the Flow Form, and 20 might not be too bad for the rokkaku. But I won't know until I try, and I certainly won't hang a camera from either one until I do.

    Deflecting using a sail will still carry with it penalties. If nothing else, you're carrying additional weight on the line. That's pushing the envelope in a different axis, but it's still pushing it. You're applying lateral forces to the line by adding a second aerodynamic device to it. Recovery may be more complicated in case the kite does go off in a strange direction since you're flying two sails instead of one. And line forces will still add. I'd like to see this technique tested to the point where the kite/sail combination won't fly any more, just so we know what the limits are.

    I don't think either of these methods is as simple and straightforward as it seems at first glance. I expect there will be gotchas with each of them. The safest path would be to fly the kite directly downwind at all times. But then again, the safest path would be to fly the kite at the center of its wind range and not go too high or too low, even if it will still lift a camera. Flying toward the edge of a kite's wind speed range puts it closer to the edge of its stable envelope, after all. Come to think of it, the safest path wouldn't be to hang a camera on the line because even that will degrade the performance of the kite. We're always pushing the envelope every time we hang a camera on a kite line. The question is how much we can push it and still bring everything down safely at the end of the flight.

    Tom
  • This whole subject, as a subset of KAP and kiteflying in general, has become extremely interesting -- much more than I ever anticipated. Tom, your efforts and explanations would no doubt inspire both Mario Andretti and Leonardo Davinci. So would others'. You guys are the greatest.

    I cannot wait for whatever comes next from each contributor. Many thanks for all the input!
  • My understanding of the skyhook is that it is the inverse of what Simon is suggesting. A stable sail part way down the line that helps keep the main tacking kite up in the air where it can recover from small dives and wobbles without hitting the ocean.

    I have limited experience with kite trains so I don't have a great feel for which is better. My instinct is that Simon's train of thought is going to lead to more stability under gusty conditions.
  • Just to be clear, I'm really not advocating any one method over another. I just think it's cool that it's possible to tack a kite off wind! Simon, I am interested in the tacking sail on the line, the way you described. I don't have a way to play with this myself, so I'm curious to see what results can be had with it. Every trick in the bag is a solution for a roadblock that might come up down the road. It's all fair game.

    Tom
  • I tried to fly my fled yesterday and it worked to some degree. By that, I mean it was still very stable with the simple bridle on one side taken up - to about 4 inches - but continued to fly at such a high angle that the off-wind angle did not net out to more than, say 15 degrees.

    Wind was smooth and 10mph+ and height was perhaps 300 ft (yipes! it does pull pretty hard). Sorry I was not being nearly as scientific as I should. Still have high hopes for the Rokkaku and the Flowform.
  • I had a flight yesterday, too. It was urban KAP with more ground hazards than I like to work with. The wind direction just barely let me get the angle I needed to get over the subject. Simon, just for the sake of argument I did the mental exercise of asking myself if I'd put up my rokkaku with an offset bridle to tack it into an angle that gave me more room to work.

    In short, the answer was no. Like you said, offsetting the bridle like that does compress the flight envelope of the kite. The camera was over a playground, and the kite was out over a street. I knew it was safe for the kite I chose (Fled) and the conditions (dead smack in the middle of its wind range, and a nice steady wind) as long as I kept the flight short, to the point, and was ready to bail at any time. Everything came off without a hitch. But push comes to shove, I wasn't willing to tack a kite to improve the working conditions. Maybe once I've tried an offset bridle for a couple of years and have seen it work AND seen it fail. Maybe then I'd trust it. But not yet.

    I'm still not convinced the tacking jib downline from the kite is any safer, but I do take your point that this isn't to be taken lightly. Good on ya. Thanks for raising the red flag, Simon.

    Tom
  • Has anyone else been able to try techniques with Flowforms or delta kites? I'm still hoping this works really well with a Rokkaku.

    If I do get a Rok for this, it sounds like I may need fibergass spars for the higher wind range needed for the required lift. I do want the ability to go up all the way to 20+ mph.
  • Just found this link on Pauls Fishing Kites, look down the instructions until you find the tacking section. This is for the nighthawk kite. Basicaly hanging a plastic carrier bag off a line attached to one wing or the other.
    Kite flying instructions
  • Apologies for reviving this old thread, but the challenge to fly off-wind flying remains as the Fall beach season approaches. (For all the "reasoning," please refer to previous info in this thread)

    Sue and others recently got me to thinking that perhaps a Power Sled 24 could have the bridles shortened on one side to achieve a bit of a tack, as in sailing. While I do not yet have a Power Sled, this seems very reasonable. Has anyone ever tried this -- or perhaps willing to try, and then report back?

    One note regarding Sleds in general is that they are reported to wallow and/or go from side-to-side, catching and spilling air. While that can certainly be a problem for KAP, MAYBE (?) putting the kite on an off-wind angle would allow it to spill air more readily/smoothly and perhaps be a little more stable? Just food for thought.

    In any case, has anyone else out there had any success in flying off wind, whether you were TRYING to or not? Any comments, observations and help is welcome, with my thanks!

    Phil
  • I haven't really played with this any further. Before rolling all of Jim's mods into my G-Kites Dopero, it would fly up to 70+ degrees off-wind in random directions (basically exploring its wind envelope like a sport kite). But to go back to one of Simon's earlier comments on this topic, rather than get excited by my Dopero's behavior, it scared the bejeebers out of me! Only a couple of times did I have a rig on the line when the kite was doing this. In every case I was terrified.

    The experiments I did with the offset rokkaku bridle led to far more predictable and stable behavior. That might be fun to return to at some point. But I'm not sure if or when I will. But if anyone else is interested, I'd be interested in reading the results.

    Tom
  • Phil,

    I'm doing well and loving KAP I hope every thing is well with you.

    I have not KAP with the 24 since june but I still fly it every once in a while with a 15ft fuzzy tail.

    When I did KAP with the 24 I had to use a fuzzy tail to stabilize the flight without it the flight was a little erratic for KAP.
    It definitely needs a smooth constant wind, any wind over 15mph it pulls like a horse.

    I highly recommend this kite because how easy it is to setup and stable flight for KAP.
    It has never dive on me like my deltas have and the kite is definitely of quality build.

    I have been using my Fled and PLK Pilot 2m2 for the majority of my KAP work these days.

    Take care,
    Nest
  • There was a suggestion earlier that an R/C glider could accomplish this through weight shifting-- here's a video of just such a glider. They raise it by flying it like a kite, so it's a pretty good demo of such a technique. I suggest you mute the terrible soundtrack.

  • Mathew, Thanks. That is a pretty neat suggestion -- weight shifting the rig from side to side -- and interesting video of the parasail as well.

    I think that since dynamic setting of the kite sail would not be required to change during a given flight in steady wind, I would opt for something that could be set on the ground before launch... even if it was an off-center rig of sorts. Even that may be a bit too much of a challenge though.

    I believe I will go ahead sometime next week with the purchase of a Power Sled 24, since it is not terribly expensive -- and do some experiments unless someone can give it a go with shortened bridle on one side and report back here fairly soon....Anybody want to volunteer? Sue? Nest? Anybody else with a power sled?

    Phil
  • I saw only Powersled 14 flying with one bridle about 1" shorter. It flew leaning to a side by about 30-45° but not much off wind (probably its tail was pulling it into the centre of wind window.

    rgds
    \Seb
  • Phil,
    That's my impression too. A drag or bridle based tacking system like fishing kite folks are using seems to be an easier solution that will work with my existing KAP kites. Weight shifting would probably take a whole new design built around having a weight that close to the kite, like that rc parawing. I definitely want to tack with my deltas like PFK.
  • Phil,
    It really sounds like a dual line stunt kite would work well for this, but I realize that it would be very difficult to keep the lines balanced while launching and retrieving. Limiting the control control authority would also be difficult with a traditional dual line stunt kite. I was thinking of a stunt kite variation that would use a traditional delta with a single line attached to the keel and having a second tack line that is much smaller (e.g., 4 lb mono) that could be attached to the side of the kite that you wanted to tack towards. The tack line could normally be left slack and only pulled on when you wanted to tack the kite. I'm not sure if this technique is already used in kite fishing, but sounds like an interesting thing to experiment with.

    Mike
  • Mike - So great to have you back here.

    A good while back I tried what you mentioned ( a statisical sample of 1* ) with my Standard 9 foot Levitation Delta, expecting that off-wind result. But, in that one case, the kite made a very large circle -- never really diving or doing anything erratic in the steady wind, and also staying pretty high, but still making a 150-foot gentle circle at the end of 400 feet of line.

    *Perhaps I should try this again a few different ways, taking measurements and notes.

    Also, can someone chime in as to whether a PFK Mega Mouth may be just the ticket? If so, maybe the three pockets of a power sled can be closed together, to simulate the sled. (Although no doubt worth the price, the megamouth is more than double the cost of a PS24)
  • Phil,
    I got a crazy idea today that may lead to a way to fly your kite off-wind. PROCEED WITH CAUTION when heading down this path as it would be very easy to over do it and fly the kite and rig right into the ground!

    I tied a small control line to one side of the spreader spar (the side I wanted it to tack toward) of my Levitation delta and threaded it through a ring on the main keel attachment (see first figure below). I left the control line slack while I released the main line to get some altitude. Then, I gently started pulling on the control line and was able to get the kite to fly off-wind by at least 45 degrees. It reminded me of flying an old Skynasaur stunt kite, except when you release the control line the kite automatically returns to its normal flying position. The wind was very gusty so it was hard to control and I was not able to get a good video since both hands were tied up (literally).

    I'm not saying this is a viable approach or not, but may be worth investigating further if you're interested to see if you can tame it and make it safe and suitable for KAP. It would be good to limit the authority of the control line by putting a stop on it between the spreader and keel ring so that the amount of control is limited. It would also be good to pre-load the control line with a bunge or rubber band so that light pulls on the line would not affect the flight (pre-load the control line so that you have to pull hard enough to extend the bunge before it makes the control line taught and steers the kite).

    Have fun, and be careful out there ;)

    Mike

    Tack Control Line 2

    Tack Control Line 3
  • Excellent, Mike! I will try this as soon as possible and when the weather permits.

    If this works for the special purpose mentioned here, I will go ahead with a servo mechanism local to the kite to pull-in the control line, and add the stop mentioned as well. Cool.

    I see you are using a tail - is that 15 foot ?

  • Nice Mike! Awesome to see some results. I'll have to try that with my levitation as well.

    running a line between the bridle point and the spreader spar on the side you want to tack to is what Paul's Fishing Kites are also suggesting, only they then attach a plastic bag to that line for drag. Your method seems to provide a lot more control.
  • This is an intersting approach, but keep in mind that I didn't have more than about 5 minutes to try it, so there's still a lot of evaluation and development to be done before we know if it's viable for KAP (I'm still a bit skeptical). One of the trickier things will be managing release and retrieval of the control line while making sure it doesn't get tangled or pulled on inadvertantly and cause the kite to take a dive. It will be interesting to see how things develop with this.

    Mike
  • Hi again
    I've been out flying today for "one sky one world" day. I took the oportunity to test shortening one bridle of the Power Sled 24. I also flew the PS 14 to show the wind direction. The 24 did fly to one side but it became unstable and flew on it's side like sport kites do. The 14 stayed flying well.
    The wind was f3 and gusty.
    I also use luggage scales to see what the pull was on those two and also the 2m Dopero Drone.
    PS 14. 1-2 kg
    PS 24. 2-5 kg
    Dopero Drone. 3kg steady.
    The PS 24 easily carried a 500g/1lb bottle. When a gust came, the line was almost straight.

    The Power Sled carrying the 500g bottle

    Power Sled 24 and 500g bottle

    The bottle on the line when the wind blew f3/4

    500g bottle on Power Sled 24 strong wind (4)


    the bottle n the line when the wind blew f2/3

    500g bottle on Power Sled 24 lighter wind (2)

    A (sideways) video of the Power Sled 24 with the bridle shortened quite a bit on the right hand side. Power Sled 14 at RH side



    Fly High

    Sue
  • Thanks for that video, Sue. That is very kind of you to try it out and share. Looks promising as long as the string is not shortened too much.

    As some are aware, the wind picked up in the SE USA recently, so the Levitation keel-to-cross spar idea was tried here in Sumter yesterday. The results were not very good. The kite circled at a low angle and crashed on occassion. The wind speed was 10-14 mph in the main stream.

    What I tried was the following four approaches to cause constraint on one side of the kite:

    * A slightly shortened line from keel tow point to end of cross spar;
    * Same thing, but from kiteline 1 foot from tow point;
    * A line from end of cross spar to keel tow point to end of trailing wing spar;
    * Same as above but from kiteline 1 foot from tow point.

    On the Levitation Delta, as Mike LeDuc has pointed out so many times, the wings flex back progressively with changes in wind force. I think that may have have a lot to do with my constraints failure (no progressive flexibility allowed at all on one side).

    Soooo .... I will keep this project in mind/incubate while working on a few other unrelated tasks over the next few months. Thanks for all the input.

    Phil
  • I've been curious about steering KAP too. This Saturday I went out to a local park, fairly hilly. I turned my Rokkaku into a two line kite. I tied two lines onto the lower end of the bridle of my 78" kite. One line was going to the top and bottom of the right side and one line was going to the top and bottom of the left. I just left the regular bridle attached so the last few feet were dangling. This gave me about 2 feet of differential capability, without much shortening of the total length.
    Winds on the ground were gusting to 18 mph, and the air there was somewhat turbulent. Nevertheless, I was able to steer the kite about 45 degrees to either side of straight down wind. Total travel was around 90 degrees. It was not super stable but I think that's because the wind was too strong and messy. I thought it seemed quite promising actually. I was even able to land it fairly gracefully at the edge of the wind window. (I have some experience with 2 line kites). I didn't try attaching a camera rig, given the conditions. It did a few odd side sliding movements that I haven't seen a 2 line kite do. Again, I bet it would be much better with smoother lighter winds.

    I like the idea above by Mike to have a main line and a control line which seems like it could work with the Rok too. The weight of the control string and its drag in the air will also be light pulls, tending to give it an offset (it won't fly straight downwind anymore without some sort of bungee scheme like he describes.). But that may be ok.


    I also tried pulling on one side of the three strings going to my flowform 16, which was not promising. Then I also tried tying a line to the bottom corner of the flowform. This worked as well as expected, driving the kite maybe 10 degrees off wind and then forcing it into a dive.

    hobbiestoomany
  • On Saturday I tried using two lines on my 78" Rokkaku. I tied the two lines onto the bridle about 2' before the point where the left and the right side normally come together. This left the end part of the bridle (where the line usually connects) just dangling.
    The conditions were too strong (gusts to 18 mph) for this kite, and my spot was somewhat hilly (turbulent), but it was clear that this would probably work fine in better conditions. I was able to swing the kite about 45 degrees off wind in either direction. It helped to have some 2 line experience. I was even able to land the kite somewhat gracefully on the edge of the wind window. I didn’t try a rig in these poor conditions.
    hobbiestoomany
  • Paul Barnes of Paul's Fishing Kites has two youtube accounts, So I'd missed these awesome instructional videos called the Kite Fishing Encyclopedia he made in '96. He explains about kite tacking in videos 1, 3, and 4. I put notes on them up on the Public Lab site:
    http://publiclaboratory.org/notes/mathew/2-1-2013/how-pauls-fishing-kites-flys-wind

    The basic trick is using a combination of off-center drag and a little weight. These screenshots from part 3 give guidelines for PFK Delta owners:

    Kite Fishing encyclopedia

    Kite Fishing encyclopedia

    Kite Fishing encyclopedia
  • Last sunday I got a chance to test out off-wind flying with the three tail attachment points on my G-kites Dazzle delta in super low winds less than 4mph on the ground, a little more above. not enough to lift a camera. I practiced in the Willamette Valley (portland, OR) for the steady winds, and also to use the Steel Bridge in the background as a reference. Since the wind blows straight up the valley, I'd like to try off-wind flying to be able to photograph the bridges from the middle of the river without flying from a boat.

    I flew the delta with four different tail configurations-- no tails, two tails- one from the middle and one on the left side, one tail on the left, and two tails on the left. Two tails on the left got me about 35-45 degrees off wind, about 1/3 of the way out into the river. I'll have to go back and see how it flies in higher winds with that much asymmetrical tail. The wind was too low to try adding weight to one side or the other of the kite. That said, in these preliminary tests the kite was extremely steady, I was quite pleasantly surprised by its performance. I expected small gusts to send the kite spinning, but it maintained a fairly even tack.

    A quick overlay of the flights:

    overlay of off-wind flights

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