After reading the success of Mike le Duc with the Levitation delta I thought I’d get hold of one and try it for myself. I know this is a favourite of many, particularly ‘Kappix‘ Ramon who was very helpful with advice on up-rating the spreader spar. It is reasonably priced but a bit awkward to get hold of in the UK. I ordered mine from Into the Wind (ITW) of Boulder Colorado for $75 which seemed reasonable but the cost of shipping and taxes soon dented the advantage over a German supplier. The kite is available in 2 formats, one with fibreglass spars and one with carbon (known as the Levitation Light) I have the cheaper glass fibre sparred one.
I replaced the 3 piece glassfibre spreader with a 2 piece 8mm carbon fibre Skyshark 8P one.I had to wait for the wind to calm down before I could give it a try and, sadly once agin I missread the wind trend: I launched in what I thought was a lull in the bluster and found the wind building in force as I flew.
The record shows I missed the lull at 4pm and I was out in gusts of 30mph. This explains the movement of the kite: it was weaving about with a strong tendency to heel to the right. I checked the balance of the new spar (I reversed it) but this was not the problem. Next I swapped back the spreader for the fibreglass original (kite flyers will know what happens next and I was ready for it but I wanted to see the difference in performance) …immediately the flight was smoother, its plan shape sharpening as it absorbed the air pressure on the sail, it flew smoothly with less weaving and a much steadier pull on the line without jerking. I could see the spreader spar bowing in the gust and couldn’t resist pulling on the line to watch it work. A flexible spreader spar is far better than a stiff one!
One tug on the line too many and the centre section of the spreader snapped like a twig …ploof!…and the kite dropped to the ground.
So in a very short flight I have learned 2 important things:
- The spreader spar on the delta should be flexible.
- A glassfibre spreader is not up to the job.
By using the high strength carbon fibre spar the upper wind speed of the kite is increased at the cost of its flexibility. Experience with the PFK Nighthawk shows a massive tawa hardwood spreader allows the kite to fly in up to 40Kt winds and seeing the effect of a flexible spar now reveals to me why the ride is so rough: despite flexing its leading edges the rigid spreader spar won’t let the arrow shape ‘sharpen’ to ride the fluctuation in airflow smoothly. Up to now I always found the Nighthawk a bit erratic, tending not to sit on the wind too well with its nose ‘hunting’ the slightest variation in flow…the PFK works but it drives me nuts with its weaving and swooping so I have kept the delta at the bottom of the pile, only flying it when nothing else will go. Now I know why: a rigid spreader spar= high top wind speed with low flexibilty. Now I’d had a hint of how well a delta works with a flexible spar I wanted to know if the stiffer replacement was a reasonable light wind option. It certainly held up ok, if a bit skittish in the 30mph gusts but would the extra stiffness kill the light wind performance?
I waited for the lull and read the instructions to check the advertised wind range for the kite:
Launched into the next pause in the wind I discovered this thing likes to float! Provided there is some movement in the air its posisble to fly it and, with a long lead on launch, it can be flicked into the air, towing it gently to keep its nose up, it takes ages for it to drift back down again! It is possible to find the slowest towing speed and keep it in the air in almost no wind at all. In the lightest air the slow movement of the kite becomes dance like and the balance between paying out line and pulling it in can keep it turning in to the wind from its apex overhead to the ground in slow sweeps across the face of the wind- this kite works almost like a free wing! With enough height it will simply hang in the air as the line slowly slackens beneath it, I can see how it got its name and also what sort of KAP I can achive with it: it’s never going to be a nail in the sky for a directed camera but I think it will make a match with my lightest rig in one form or another.
Trials in a steady 5-7mph find this kite smooth as silk its trailing edge fluttering with a gentle crackle to let you know its there. In Bft2 the Levitataion lifted 500g for an hour or so as the light faded I can see why its such a well recommended kite.
Mike LeDuc has demostrated an answer to the strength/flexibility problem on this kite and, in time, I’ll adopt his method: the ‘dynamic spreader’. Having cut my precious Skyshark 8p to get safe top wind performance I’ll get more flying time in its designer Christoph Fokken’s original design state, and adapt a KAP method to it before tinkering further!
I’m not a delta addict yet but I can see how it can happen!