January 2008

Newsletter, January '08.

Kitesailing dreams - and I make a new year's resolution to never travel again.

Actually this last was a pious wish (new year's eve being a particularly spiritual time) but oh how I wish!

Last year I was on the road so much I never did get much done.  Some traveling is useful because of thinking time on aeroplanes and stimulation from meeting kite people and seeing new ideas, but 2007 was way over the top for me.

Unfortunately, no matter that various witnesses now daily remind me of my loudly declared intent, not traveling is just not possible.

The many events that supported us during the years when we were getting established have fair claim on my support now.  Also, the growing number of kite festivals in Asian and Islamic countries- with their underlying purpose of smoothing international tensions- have a higher claim than anything else I could possibly do.

Elwyn is not that impressed by these claims for the high moral ground though- she reckons I just get stir crazy after a few weeks at home and make a break for it-, which I strenuously deny! 

Everything I want is right here- top standard residential care, the best cat in the world, a great workshop, family, friends, lots of toys, and stimulating company (this holiday season we have 8 visiting kite people- some of whom are staying through until the beginning of winter).  Perhaps the only thing missing is useable mid range winds at ground level- the usual whinge- but our new kite field down the back has improved things a lot- actually the wind there is bad, but proximity makes all the difference.  I can drive to a reliable onshore breeze beach in 1.25hrs, or to closer places with decreasingly useable wind, but for total time/test, bad wind here often trumps good wind further away.  The frustration index is fairly constant across the range- driving for an hour to a wind that dies as you arrive about equals 2 hours swearing at the rubbish wind available in our back yard I reckon.

So, New Year's day being a time to take stock, what's been achieved in the last 12 months?

Except for progress in developing a theory of single line kite flying (from sitting on aeroplanes for far too long), basically nothing.

Commercialisation of the AP 'foil has been extremely frustrating, hasn't yet happened.  Although in 2007, the current prototype (an 8m) gave me some of the best buggying I've ever enjoyed, it does have a technical problem, can luff without warning in strong gusty winds.  The cause is simple enough, the cure probably ditto- but requires that profiles and skins are purpose built to conform to AP principles (until now we've just been re-bridling existing designs).  Some one give me a kick up the bum so I make this happen please.

The Slarcs are being held up by patent issues- that is, the IP (intellectual property) that derives from the Slarcs has wider application than I first thought, so is taking much more time and thinking than expected.  This is also holding up some other kite projects I'm working on because they can't proceed until this IP is settled.

 Also I'm disappointed by the Slarc's light wind performance. As expected, (heavier for their projected area) they require marginally more wind to stay up than our pilot kites do- perhaps 6km/hr as against 5km/hr- but where I came unstuck was in failing to understand the consequences of this.  Unfortunately, when wind is marginal, even a tiny difference in wind threshold makes a huge difference in how often re-launching will be required.  Seeing as the Slarc is intended for kitesailing (the first law of kitesailing being that it doesn't happen if the kite's not flying) this is VERY DEPRESSING!

On the plus side, the "longboat" monohull kitesailing boat from early '07 is quite clearly definitive.  For larger kite powered craft, it's the answer- but what use without useable kites?

What is currently constraining kitesailing then? 

Kite performance?  Kite lift/drag ratios are adequate- sure, kite powered boats cannot generally match the upwind performance of conventional sailing craft, but they have enough other advantages (less heeling, and better downwind performances for example) to compensate for this.

Kite de-power? (sheeting, reefing ).  It used to be that kites had zero effective de-power- their pull was proportional solely to apparent wind speed.  Now various styles of kites are available that allow the operator useful pull control- 50% or more.

Safety?  With the development of various releases and kites with complete de-power systems, out of control overpowering is much less likely than it was. There are plenty of recreational activities now that are inherently more dangerous than kitesailing .

Launching? The big bugaboo- but I've never really bought into this being a limiting condition. In addition to LEI's and closed ram air kites ('foils and Arcs) that launch quite well off the water providing there's enough apparent wind, there are many useable systems- mast launching, motor launching, pilot launching, and lighter than air kites (but only in large sizes).  Some of these systems are slow and require skill (same as for a spinnaker), but they are reliable; always work eventually.

Light wind flying? To my view this is the major remaining problem.  Overwhelmingly, the days when things don't work are because of insufficient wind. I would say about 10/1: for every day when the wind is too strong, there are at least ten when there's not enough. While on the water, there's nothing as annoying as wind that won't quite keep the kite up- and this happens day after day after day. We can of course choose to stay on the hard for those days, but when your lake/harbour/sea is sprinkled with conventional sailboats having a jolly good time, sitting on the shore is not exactly going to promote our vision of how to go sailing.  Of course, we could choose to do our kitesailing in places where the wind is sufficient - like Maui- yeah, right, but when I last went there for a few days kitesailing with Don (Montague) et al, we never did get on the water except by paddle power because, you've guessed it; there wasn't enough wind.

The underlying problem is that sails are held up by their masts, kites require wind- and worse, even a 30second lull kills a kite, whereas a boat with a mast and sail will ghost through such a lull with passengers blissfully unaware.

Is this solvable?  On a bad day I think it's not.

On a good day I remind myself that apparently insoluble problems occasionally get solved or by- passed.

Lighter-than-air kites are one obvious answer- but this is only possible for kites of more than, say, 100sq.m (because of weight/volume ratio) and helium is expensive- and leaks away at an alarming rate.

Also very large LEI's are said to fly in very much lighter winds than smaller ones- why this should be so, aerodynamically, is intriguing, but that it is so I don't doubt- given the observers I'm quoting.

It's true that kites are not equal- some are better in the light than others.  The very best light wind fliers are NASA style single skin frameless kites- they fly in winds you can barely feel. When Chris Brent and I tested NASA's against Arcs using identical KiteCats in 2005, we found not only that the NASA's allowed kitesailing in much lighter winds, but that the performance crossover was at much higher wind speed than we expected.  NASA's have L/D's of around 3, Arcs  >5, but even when the wind was more than enough to allow the Arc to be parked solidly in a corner (+/-15km/hr), a NASA of similar size would still beat it around an upwind/downwind course.

There is hope!

Happy New Year!

Peter Lynn, Ashburton, Jan 1 '08