F-Arc Motorized Paraglider ?

[Paul Isabelle]

Hi all,

I have been thinking about developing a motorized F-Arc e-paraglider for quite some time now. The F-Arc peel up launches easily, generates tremendous lift, is low drag (great upwind performance) but with unfortunate bowtie susceptibility.

Kite surfing in unstable winds with the F-Arc is almost useless due to the short relaunch window on water (not so bad on snow). My lower aspect clones (900, 1400) are much better regarding this but with less performance whereas higher ones (1900) can be most challenging with only modest performance increase and a tad of quirkiness. The vanilla 1600 would be a good start.

Using such an efficient wing as the F-Arc for a paraglider seems most attractive to me. Bowties may be less an issue since we cruise in light winds, at a very constant speed, with gentle turns and pitch correction. Apart from doing something silly and stalling the F-Arc, bowties or inversions should be less an issue. Lower surface area and higher wing loading implies faster speeds. Not an issue.

Proof of concept

I will be trying the F-Arc 1600 on a small 9.9HP 14foot fishing boat on which I will install a cross bar shortly. The two tow points will be a good 5 feet apart. The front lines could go to the middle of the bar, however, they could also cross and attach to opposite ends. The idea here is to increase autozenith reactivity, keeping the kite parallel with the bar at all times.

Questions:

Has anyone ever heard of an autozenith setup like this? Does it work? Are there thing to know?

Would steering the kite be better (kite turns, craft follows) than a rudder or direction of thrust (craft leads, kite follows)?

Perhaps an active kite control system (Arduino, sensors, servos) would be better? The lines and kite could be spread apart with much shorter lines.

Not a good idea ? 😞

Paul in Quebec City Canada.

[Gulf Kitesurfing Paradise]

Bonjour Paul. Peut on en discuter ? WhatsApp 0097332233327 

[nigel]

I have to ask, why?

Past generation fixed bridal race kites, like Vapors, Combats, Yakuza's, or current generation de-power race foils (R1's, VMG's), would have superior performance to the F-Arc.

They would also have less handling "quirks" (bow tie).

 

If your committed to the Arc.

A few people (and Peter Lynn) have played with adding a bridle to an Arc before.

This would remove the bow tie issue.

These bridled Arcs have an "A" and "B" attached to the cells at different points.

I happen to have one of these from the secret squirrel works at the PL factory.

Leading edge is on the right hand side in the pic.

 

 Thinking of my safety, wouldn't a proper rated wing (paraglider wing) be a better option?

These high performance kites might over fly when attached/anchored to a base of some sort.

I know from experience, that when a kiter is in the air, you need to pull the brakes on as you descend, to stop the kite over flying.

So you will have to back bridle, or increase the AOA of the kite in some way to stop this. 

A performance loss?  If you need to fly with the so called "brakes on" all the time?

 

Keep us informed of your progress, and good luck.

[Paul Isabelle]

Thank you for your feedback Nigel, particularly when it involves safety.

I have several F-Arc 1600s that I purchased from Gavin years back, hence my interest in repurposing exploration. Another is an AWES with dual line winch for power transmission, ground based flight control system, onboard fly-by-wire steering.

Overflying is a definite issue with this kite when flying it for its intended purpose. It frequently does this in a gust, passing zenith, stalling and falling back into the wind window, sometimes quite dramatically;-) I do not have much experience with jumping with the F-Arc on water so I do not have a good feel for this aspect. In flight, would the suspended pilot not accelerate and catch up with the kite? On water, we land before this would happen which becomes a problem when we want to power up before we sink… Perhaps, like you suggest, maintaining AoA by having a paraglider type attachment (common flying and brake line point, limiting AoA lower range) with steering loops for control could work.

Bowties are a real nuisance with ARCs with an AR over 4-6 due to their bridle-less attachment. My many attempts with bowed tip spars, inflated tip cells, a line between rear tips, bungees on the brakes and such have all failed. Active inflation (stripped down computer fans in the inlets works well, indicating that bowties may be due to loss of internal pressure in the lulls. Moreover, a bridle may open up the kite a bit, increasing AR and performance like a bow kite. Having spools of fine bridle spectra, I will definitely explore this.

Thank you for the input! Food for thought, and prudence…

Dear Nigel,

I do not see a LE webbing strap in this image. Could it be that Peter’s bridle system replaced them? That must be an interesting kite.

Paul.