PEELS:  THE FUTURE

The potential is huge.  Firstly, I have no doubt that current primary
bridles, cross bridles, rib profiles and rib spacings are not optimum.  A
simple and informative experiment with Peel development was to
construct some prototypes with twice as many ribs and bridles as the
standard.  The results were as expected:
1.      Higher L.D.R. (goes further around the edge, and over head, has
        less pull at its equilibrium over head position than standard
        models)
2.      Faster
3.      Smoother skin less wrinkles, especially along trailing edge.
4.      Marginally more liable to collapse - thinner, has less compressive
        strength from internal air pressure.
5.      Less liable to "clap hands" - thinner mid section has relatively
        less drag, wing tip drag doesn't change as much.
6.      For buggying, generally slower around the course.  Top speed ,
        especially on reaching legs, is higher.
7.      A problem is that, the weight of ribs approximates to the weight of
        the lower (or upper) skin.  I have thought that this significant
        overall weight increase would have dramatic and damaging effect on
        light wind performance and on that very critical situation in
        stronger turbulent winds when the kite flies into a "hole".  From
        experience flying wet kites, (rigid frame single skin, soft or semi
        soft) kite handling characteristics deteriorate alarmingly.  More
        recent tests seem to be showing that flying characteristics are
        more dependent on how weight is distributed rather than the total,
        and that wet kites lose performance more because the fabric
        becomes soft and sticky than because of increased weight.

One obvious improvement for Peels is to use Spectra, or Kelvar or
Technora bridles.  Of course there is a cost penalty but drag is
significantly decreased and because bridle drag is below the kite it
usually exacerbates luffing problems. Work that Nop Valthuizen has done
on high speed Flexifoils has shown that top speed is incredibly sensitive
to line diameter.  Experience here supports this.  Thin spectra bridles on
Peels improve speed significantly and seem to improve control as well.

Thinner bridles are always advantageous and have no performance
disadvantages.

Scale effects penalise most bigger kites but Peels are relatively exempt
from this.  Using Bainbridge 3/4 oz ripstop,  the 5m peel is about maximum
size for available fabric strength (fabric stress for soft kites is
approximately proportional to cell size not to kite size.  Using actual
42gm Polyant or Teijin larger size kites are okay (X2!).  Hence a larger
kite (up to the fabric stress limit when fabric weight must be increased)
will not suffer light wind performance deterioration. 

I believe that, in spite of the extra weight, Peels with more ribs will be
the trend because they offer higher top speed and higher L.D.R.  Answers
must, can, and are being found to C.P. Luffing, A.W. luffing and weight
problems.
Reefing is an absolute must, preferably with constant L.D.R. and
hopefully to below 50% of at rest area.

During 1992 there have been some exciting developments in Peels which
could totally revolutionise traction kiting.  Of course, "there's many a
slip twixt cup and lip" and I'm not anything like 100% confident that all
the new systems will work together in the way I hope.  There are also the
problems of what to do about gaining protection by patenting etc and
then how to go about orderly development of the new markets that should
become available.

The first new development is a retrofittable quick steering system. 
Using the (I think new) principle that additional "information" can be
passed to a two line kite by using a pulley or etc system on the kite
which only comes into operation when the kite is "oversteered".  For
example, this can be used to operate trailing edge flaps when more than,
say, 400mm difference is detected in the main lines.  The
effect is dramatic and can be used with almost any two line kite,
although it doesn't improve kites that already have rapid turning.

More profoundly, new traction Peels are being developed that use only a
single line and are controlled by radio.  Control can be applied to
steering as for current two line kites, additionally,to control angle of
attack (now available only with 4 lines) but there can also be servo
control of reefing and the line winch.  Although not tried yet I anticipate
that the winch control will be on the basis of setting limits.  When the
line pull drops below a (settable) figure, the winch will automatically pull
in - this should effectively eliminate apparent wind luffing.  Above an,
also settable, pull the winch will automatically let out.  With up to say
1000m of line available this should significantly reduce the problems of
gusts and those terrifying surges of line pull that occur during changes
of direction.  At one end of the scale a hand held system should be
possible for buggies - one hand, finger tip controls, self launching and
retrieving of course with a belt pack battery - expensive, say more than
Dm 1000 retail for the hand control but it will sell.  At the top end of the
scale ocean going kite sailing should become truly practicable. What is
there to prevent the building of a 50m2 kite system for 12m purpose built
yachts.  In the middle scale small recreational kite sailing (in the
windsurfer size range) should become really practicable.

This system has further potential in that with the addition of available
gyroscope inertial control systems (ex model radio controlled
helicopters), it will become a superior lifting kite for cameras and
scientific equipment - 8 km/hr to 100 km/hr, and 5000m altitude, 100 kgms
payload if necessary and controllable from the ground as to lateral
position within a wide arc.