Kites & kiting

Turtle · August 1, 2013

All packed & waiting for pickup so killed some time re-sticking Matilda. :rolleyes: She is the proud new owner of a pair of 3/4" X 3/4" aluminum 90º- angle-stock wing-spars. Got a little filing yet to do on the ends to cut down pocket-pokeage problems. I think I will stay with a single cross-spar now, but move it down and make it aluminum too. Unlike aluminum tubing, this angle stock twists so can't wait to see how it behaves in flight.

Speaking of flight, I must take it. Keep your timber limber and don't let your meatloaf while I'm gone!! B)

DFINITLYDISTRUBD · August 2, 2013

Good flying today here on my little homestead.

Have given up on trying to get the big guy airborne here, too difficult to get past ground turbulence....with all of the obstacles to the wind one simply needs to do too much correcting to keep even a little kite aloft meaning it's pretty much impossible to get a kite 1/7th the width and 1/11th of the length of the field up.

Now for the little guy:

After much battling with the rapidly shifting and slacking wind he finally made it above the trees (only took half an hour of trying to catch the available wind just right). Escaping the "dirty" lower breeze he steadied right up and started taking line eagerly. After several minutes of paying out 15# mono-filament as fast as he could take it, thoughts of "ok what the heck am I going to do if he dives" crept in and I settled into just enjoying watching him work and wander in the steady higher winds...this lasted for two hours....very relaxing. With the kite being a very far off speck I found myself wishing I had an altimeter on board. Deciding it was time for a smoke and realizing I had forgotten to bring any out it was time to reel him in....what a workout!!! I was in for a lonnnnnnnnnnnnng arduous battle of endurance. In total recovery time swallowed up more than 20 minutes of constant reeling the line back onto the spool as fast as I could wind. I've no idea how much line was payed out but the 5,000 yard spool was well over half gone. The last 150 feet or so required a faster more desperate arm over arm technique as he re-entered the "dirty" zone and started drifting crazily and settling, having already caught two trees earlier I was not eager to repeat, so ended up with a tangled mess of line at my feet, but the kite set softly down on it's keel in my yard a short distance away so it was a win in my book. Next flight I'ma remember smokes and the camera...another thought on the line further complicating sorting out distance is the stretchiness of the line, with each foot easily adding an inch or two to the overall length under load....should measure that at the soonest convenience....also next flight my big Shakespear is coming out of retirement, wrapped with as much line as it will hold, besides using the drag to pay out line in a more controlled manor, I expect the high gear will recover the line more rapidly than I can manually wrap line onto the spool.

Edited August 3, 2013 by DFINITLYDISTRUBD

DFINITLYDISTRUBD · August 3, 2013

Second flight:

5,000 yards of line let out....the first pic is at about 1,500....really wish I had an altimeter. Am sorting out how to mount the spool to my drill for powered recovery.

Edit: Holy crap! It dawns on me that's 15,000 feet of line or a tad over 2.8 miles! No wonder it takes so dang long to reel it back in.

EDIT: in the second pic start at the left end of my awning (as you look at it) and scroll up, it's there somewhere near that line.

Edited August 3, 2013 by DFINITLYDISTRUBD

Turtle · August 5, 2013

Second flight:
5,000 yards of line let out....the first pic is at about 1,500....really wish I had an altimeter. Am sorting out how to mount the spool to my drill for powered recovery.
Edit: Holy crap! It dawns on me that's 15,000 feet of line or a tad over 2.8 miles! No wonder it takes so dang long to reel it back in.

EDIT: in the second pic start at the left end of my awning (as you look at it) and scroll up, it's there somewhere near that line.

:omg: :bow: :omg:

OMG #1 That kite had to be about 2 miles up bro!!!

BOW #1 Beats the hell out of any altitude I have ever flown a kite to.

OMG #2 Danger Will Robinson!!! I can think of a few bad outcomes here. While I don't think your lightweight rig could directly bring down an aircraft, it could startle the hell out of a pilot if their ship hit either the kite or the line. An aircraft tangling the line could put you at risk on the ground too. Then there is a heap o' potential injuries on the ground if the kite broke up and laid 3 miles of monofilament line across the neighborhood. Runners or bikers might not see it and get cut running into it. Might snag a windshield wiper on an auto & rip it off. Tangle in bicycle gears, lawnmowers, weed-whackers and other machines with exposed rotating parts. Could drape across power lines, and while the line is an insulator, it might become a conducting line if wet. :lightning

Well, your flight certainly shows the fool-heartiness of those claiming a kite couldn't be flown steadily at 1200 feet and get reported as an UFO. :alien_dance: All the more telling is this wasn't a 'professional' kiter bent on hoaxing with high technology at their disposal. No; this was a guy in his backyard with a dime-store kite, a fishing reel, some time to kill, and no fear. :piratesword:

Nothing of the kite variety to report for my own part as I'm decompressing from my journey. Hope to be up to speed soon.

One more time then Double-D with enthusiasm. :omg: !!!! :bow: !!!! :omg: !!!!!! :hi:

:bounce: :alienhead: :partycheers: :goodbad:

Turtle · August 5, 2013

Second flight:
5,000 yards of line let out....the first pic is at about 1,500....really wish I had an altimeter. ...

It may be possible for us to calculate the altitude of your kite with 5,000 yds of line out.

First, we need some specific info from you Double-D.

#1 The weight of the kite.

#2 The weight of the line per foot

#3 The type and surface area of the kite.

#4 The flying angle [angle of attack] of the kite. (I think this is right but will check.) :cap:

With that and NASA's kite pages we can make the calculations to find the altitude. #1, #3 and #4 let us calculate the Lift and Drag, and maybe tension T, but I have to check on that T too. :sherlock: I fully expect I will have to appeal to Craig et al for help, as my trig is highly oxidized. Are you up to it Craig? Phillip? Modest? Laurie? JM? Et als?? Turtle down!!!! :help:

The Index page at NASA for the kiting pages is here. >>Kite Index

I may have put up this diagram from the Control Line Equations page before, but here it is again. Explanatory text at the link. :read:

Back to you Bob. :slingshot:

Turtle · August 5, 2013

It may be possible for us to calculate the altitude of your kite with 5,000 yds of line out.
First, we need some specific info from you Double-D.
#1 The weight of the kite.
#2 The weight of the line per foot
#3 The type and surface area of the kite.
#4 The flying angle [angle of attack] of the kite. (I think this is right but will check.)

With that and NASA's kite pages we can make the calculations to find the altitude. #1, #3 and #4 let us calculate the Lift and Drag, and maybe tension T, but I have to check on that T too.
snip..

.Back to you Bob.

Hmmmmm....looks like we need Wind speed and air density to calculate Lift. :omg: Wind speed Double-D? Your elevation Above Sea Level at ground?

The lift depends on two properties of the air; the density and velocity. In general, the density depends on your location on the earth. The higher the elevation, the lower the density. The standard value for air density r at sea level conditions is given as r = 1.229 kg/m^3 or .00237 slug/ft^3.

The variation of lift with altitude is described on a separate page. The air velocity is the relative speed between the kite and the air. When the kite is held fixed by the control line, the relative air velocity is the wind speed. If the line breaks, or if you let out line, the velocity is something less than the wind speed; if you pull on the control line the velocity is the wind speed plus the speed of your pull. The lift changes with the square of the velocity.

:faint: :fan:

Edited August 5, 2013 by Turtle

DFINITLYDISTRUBD · August 6, 2013

Lol! yeah, those dangers came to mind as well as concerns of the hazards that much line could present to wildlife.

Here's the best data I can provide.

Elevation: 797' - 820' above seal level

Wind speed 3-9mph

Kite weight: 2oz (could be slightly heavier or lighter my scale sux)

Line weight total: 1.1lbs per 15,000 feet. approx. 0.000073333 lbs/ft

Kite type: cheap delta, plastic, 48" wing span X 24.25" long. 582 sq. in.

Flight angle:?

angle when supported upside down by keel is approximately 5 deg.

DFINITLYDISTRUBD · August 6, 2013

Well, your flight certainly shows the fool-heartiness of those claiming a kite couldn't be flown steadily at 1200 feet and get reported as an UFO. All the more telling is this wasn't a 'professional' kiter bent on hoaxing with high technology at their disposal. No; this was a guy in his backyard with a dime-store kite, a fishing reel, some time to kill, and no fear.

Actually the higher it went the more stable it seemed to become, though it did, as winds shifted travel large distances in various directions....given that it had a potential radius of a couple miles I'd guestimate a 180 degree sweep to be 8.8 miles on the high side not accounting for line stretch, angle or bow...putting the average sweep at about 30 deg. one way then the other from straight out puts the average wander at 60 degrees and around 3 miles on the high side....these sweeps consumed very little time though I did not think to time them....mind you this is just speculation on my part as I did not actually track the exact angle and have no clue how far out or up due to line curve and stretch...which measured by actually stretching a 1' foot section shows 1 inch of stretch for foot with minimal resistance....no I don't know how much force...YET! I will just as soon as I sort out a means of measuring it.

EDIT: Feel free to check and correct my math

Edited August 6, 2013 by DFINITLYDISTRUBD

Turtle · August 6, 2013

Lol! yeah, those dangers came to mind as well as concerns of the hazards that much line could present to wildlife.

Hadn't thought of that one. Well, you did in fact retrieve your line and sow know harm, know fowl. :turkeytalk: :rotfl:

Here's the best data I can provide.
Elevation: 797' - 820' above seal level
Wind speed 3-9mph
Kite weight: 2oz (could be slightly heavier or lighter my scale sux)
Line weight total: 1.1lbs per 15,000 feet. approx. 0.000073333 lbs/ft
Kite type: cheap delta, plastic, 48" wing span X 24.25" long. 582 sq. in.
Flight angle:?
angle when supported upside down by keel is approximately 5 deg.

Check. Commencing to computing....

Aspect Ratio = span² / A

= 48² / 582

= 2304 / 582

= 3.95

Check the above diagram and see if you think your hanging 5º is equivalent to a = Angle of Attack, then let me know if there's a change in your answer to 'flight angle' before I go on to where I need it. 5º sounds too little to me, even for a Delta. :sherlock:

So I started working up the AR for Alida delta-Conyne the small winged one and I'm not sure how to handle the back cell sails. :reallyconfused: Unlike the square box illustrated at the NASA page, there is just one back panel per cell and it's in the same plane as the wings, but...the back sails are blocked when viewed straight on. Sould I count them? Not? How? :blink:

I also -following the NASA diagram- got confused if my cells were angled forward 30º or 60º , but I'm leaning to 60º because cos(60) is less than cos(45), and I will redo my calcs -again- and post ASAP. My working diagram attached. :clue:

Turtle · August 6, 2013

Actually the higher it went the more stable it seemed to become, though it did, as winds shifted travel large distances in various directions....given that it had a potential radius of a couple miles.
EDIT: Feel free to check and correct my math

I think a couple miles is too much if you mean from you to directly under the kite. I think our computing will give us that distance as X on NASA's Line Diagram, and the altitude Y. OK check delta roger over?

Also check my last post and confirm your Angle of Attack, which I mis-termed, 'flight angle'. :sherlock:

DFINITLYDISTRUBD · August 6, 2013

Edits: hanging angle measured closer to properly this time (oops!) in the neighborhood of 20 deg. Keel dimensions 24.25" full length of backbone, 10.5" nose to eye X 16.5" eye to stern X 6" eye to backbone. Have no idea how to use the diagram...how do you measure angle in flight?

I think a couple miles is too much if you mean from you to directly under the kite

I couldn't tell ya...2.8 miles of line adjusted for angle, altitude, ect, etc, yadda, yadda, yadda equals ???? No clue!

I needs a lightweight altimeter and GPS!

Edited August 6, 2013 by DFINITLYDISTRUBD

Turtle · August 6, 2013

Edits: hanging angle measured closer to properly this time (oops!) in the neighborhood of 20 deg. Keel dimensions 24.25" full length of backbone, 10.5" nose to eye X 16.5" eye to stern X 6" eye to backbone. Have no idea how to use the diagram...how do you measure angle in flight?

I think with the kite in the air, but close to you, you can estimate this angle close-enough. It is the angle between the ground and the front-to-back axis of the kite. I'm thinking to tie my little inclinometer right to the front longeron of Alida and take the measure, but this would be difficult with your fabric keel. I'm attaching a cropped annotated image of the NASA Diagram on Angle of Attack. Look to upper-left of it. :clue: I will have to convert your Degrees to Radians before using it in their formula. :omg: Forgot how to do that too, :loser: but no doubt it's written down somewhere. :sherlock:

I couldn't tell ya...2.8 miles of line adjusted for angle, altitude, ect, etc, yadda, yadda,[/size] yadda equals ???? No clue!

I needs a lightweight altimeter and GPS!

No worries. I have not only a clue but a set of equations and I fully intend by hook or by crook to use them to tell You! :smart: 'Course it will take longer than I expect even considering Hofstadter's Law. :lol:

PS You want my link to a $50 lightweight alitmeter again? over....

Edited August 6, 2013 by Turtle

Turtle · August 6, 2013

Well, getting lift requires getting a lift coefficient which requires a wind tunnel? :omg: :blink:

So, I input your kite specs to the Kite Modeler Double-D and got these results. Mind you we ain't to altitude yet.

line weight 1.1 lbs 15,000 feet

= 0.000073333 lbs/ft

= 0.001173333 oz/ft

-------

g = line-weight = 0.001173333 oz/ft

W = weight = 2 oz [modeler says 1.773oz for plastic kite and 1/4" birch sticks]

D = drag = 11.52oz

L = lift = 25.624oz

T= tension = 21.432oz

V = velocity = 9mph = 13.2 fps

A = kite area = 582"sq

p =

E = elevation above sea level = 800 feet

a = angle of attack = 20 deg = 0.34906585 radians

Screenshot of modeler page for Trim settings attached. :photos:

Checking on what is next. :read: The modeler does not seem to allow more than 5,000 feet of line, so I'm going in close quarters hand-to-hand. Wish me luck! :lightsaber1:

Turtle · August 6, 2013

Alrighty thens. Let's see how well I screw up finding C1. :lol: Anybody???

g = line-weight = 1.1 lbs = 17.6oz

W = weight = 2 oz

D = drag = 11.52oz

L = lift = 25.624oz

C1 = sinh^-1[(L - g - W) / D ]

= sinh^-1[(25.624 - 17.6 - 2) / 11.52]

= sinh^-1[6.024/11.52]

= sinh^-1[0.5229166]

= 0.5016146144159724309580791536331

Oui? :thumbs_up No!? :thumbs_do

DFINITLYDISTRUBD · August 6, 2013

That kite in the modeler pic looks pretty schmeckin close to what I get in flight.

Alrighty thens. Let's see how well I screw up finding C1. :lol: Anybody??? g = line-weight = 1.1 lbs = 17.6oz W = weight = 2 oz D = drag = 11.52oz L = lift = 25.624oz C1 = sinh^-1[(L - g - W) / D ] = sinh^-1[(25.624 - 17.6 - 2) / 11.52] = sinh^-1[6.024/11.52] = sinh^-1[0.5229166] = 0.5016146144159724309580791536331 Oui? :thumbs_up No!? :thumbs_do

?????????? Beats me....what is it?

The modeler does not seem to allow more than 5,000 feet of line,

wonder if there be a law pertaining to such matters. Edited August 6, 2013 by DFINITLYDISTRUBD

Turtle · August 6, 2013

That kite in the modeler pic looks pretty schmeckin close to what I get in flight.

Good deal. :thumbs_up

?????????? Beats me....what is it?

Well, I think C1 is 0.5016146144159724309580791536331. However, as I say I'm rusty with trig and not completely sure I have used the calculator properly to find the inverse hyperbolic sine. If no one replies that knows, I will have to ask someone who knows, but doesn't know that I don't know but need to know. :P

The modeler does not seem to allow more than 5,000 feet of line.
wonder if there be a law pertaining to such matters.

We discussed FAA rules early in the thread. Craig says the rules aren't laws as I recall. The law comes in when Congress authorizes the FAA to make rules. While there is a 500 foot altitude limit rule in some cases, I think your kite is largely exempt because of its weight. I'll find the pages. :sherlock:

As far as the Kite Modeler program, I think they just think no one is going to put out more than 5,000 feet of line. Obviously they don't know you Double-D. :rotfl: Not to worry as I should be able to solve altitude for 15,000 feet with the Drag & Lift values from the modeler and your given values.

Toward that end, finding C1 is now what it looks to do with Drag, Lift, total weight of line (g), and Weight of kite. Again, I just need to be sure I have used the inverse hyperbolic function key correctly on the calculator, because next is finding C2 and that calculation needs C1.

I'm fairly confident that [(L - g - W) / D ] = 0.5229166 is correct. With that value in the calculator I hit Inverse key and then sinh^-1 key to get 0.5016146144159724309580791536331. Having never done this I don't know what a normal C1 range is so I can't judge the reasonableness of my answer.

Come on you math whizzes; throw me a bone won't ya? :dog:

EDIT:

...
Technically, FAR 101 is a regulation, not a statute – an interpretation by FAA administrators of their general statutory duty to keep aircraft from crashing. The 500’ rule only applies to kites over 5#, with sting stonger than 50#.

You can get a waiver for these rules by phoning your nearest FAA ATC of FSS (unless you’re near a major airport, or city, your local FAA center is likely a Flight Service Station, not an Air Trafic Control center) and telling them what you’re up to and when. I did this a few times when I was trying to get a kite up really high. The FSS people were very friendly and accommodating, seeming interested. Also, they actually do warn planes and copters you’re there, which caused me to get visited by a lot of light planes curious to see if they could spot my kite and determine its altitude.

Edited August 6, 2013 by Turtle

DFINITLYDISTRUBD · August 6, 2013

This part prescribes rules governing the operation in the United States, of the following

(2) Except as provided for in § 101.7, any kite that weighs more than 5 pounds and is intended to be flown at the end of a rope or cable.

§ 101.7 Hazardous operations.
(a) No person may operate any moored balloon, kite, amateur rocket, or unmanned free balloon in a manner that creates a hazard to other persons, or their property.

(B) No person operating any moored balloon, kite, amateur rocket, or unmanned free balloon may allow an object to be dropped therefrom, if such action creates a hazard to other persons or their property.

It would appear that as long as I keep it light and stay away from airports I'm ok.

EDIT: should've waited, could've saved the effort of tracking that info down. CraigD's pretty good with the math stuffs as I recall...generally seems like a decent bloke. should I ask him...I'll ask 'im

Edited August 6, 2013 by DFINITLYDISTRUBD

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How often do you fly a kite? 13 members have voted

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