MBK Dowel Delta
Today cloud-base was quite low, perhaps around 3000 feet.
Ominous gray patches were sucking warmer air into the huge hidden masses of puffy cumulus towering above. Also, the inevitable larger patches of sinking air surrounded the bubbles of rising air.
Not stormy weather as such, since surface wind speeds were actually very light most of the time, but certainly the air was very active. Lots of wind-shifts and sometimes sudden increases in wind speed when rain, or just the threat of rain, was within a few kilometers of the field.
A recipe for giving the new light-wind Delta quite a work-out! Anyway, back to the beginning...
Approaching the reserve, there was barely any movement in the tree tops. However, on stepping out, there seemed to be a fitful light breeze blowing through. The wind meter, on its little tripod, registered less than 1 kph on average. Occasionally the cups stopped spinning altogether! But the clouds above were moving...
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The Delta was soon rigged -
and the wind died! I towed the thing in various directions, catching a
little breeze here, a little there.
Finally, after getting further away from the trees at the edge of the
reserve, the Dowel Delta Kite soared up on a light gust or 2. It didn't
take long to encourage the kite up further, until it was sitting nicely
in the air, on just over 30 meters (100 feet) of line.
30 meters was a bit boring, so out it went to 60... On this line
length, it was clear that there was a steady breeze up there. Steady by
in-land standards that is!
It was also clear that the kite had a
slight lean to the left in moderate wind speeds. Something that was not
evident when flying out of the back yard the other day, on a very short
Interestingly, the Delta would sometimes straighten up when
the wind strength increased yet further. Still, that lean needs to be
corrected. Today, this caused the kite to move a long way to the left at
times, before climbing higher and drifting back downwind.
The tension in the flying line was quite firm most of the time.
I've mentioned many times, this location often has a great difference
between the wind speed at ground level and higher up. One time I could
hear the trailing edge of the sail fluttering in moderate wind strengths
while the wind meter cups came to a complete stop!
Time to let
out line to 90 meters (300 feet). The big orange Delta drifted off
downwind as loops of 50 pound Dacron flew off the winder. This was
actually a little easier when I walked slowly downwind at the same time,
to lower the tension in the line.
And then, the kite just sat
there at less than a 30 degree angle for some time. Straining away in a
large patch of sinking air that took at least a couple of minutes to
move on. Finally the tips flexed inwards even more, and the Delta
accelerated skywards. At least a couple of times, patches of rising air boosted the kite way overhead. The updrafts seemed even stronger than the prevailing wind!
What the heck, why not go to 120 meters (400 feet) now? So I did. It wasn't long before the Dowel Delta Kite was vertically situated once again. Very soon after that, the lift died, and the Delta was left to hunt around in a big circle, slowly gliding earthward.
It so happened that as the kite was pointed downwind, the line tension came back on a bit... Sending the kite into a vertical dive! I watched it for a few seconds, fairly confident that it would right itself. And it did, describing a slow graceful arc in an anti-clockwise direction before recovering, still around 300 feet up. Maybe 250.
All too soon it was time to go home and I started bringing line in. The Dowel Delta Kite, however, was having way too much fun up there and resisted strongly. On and off, for minutes on end.
Finally, the kite was down to under 100 feet, when the air temperature dropped and the wind speed really picked up. Uh-oh...
With the ground only meters away, the poor Delta nearly folded itself in half trying to cope with the fresh gusts coming over the trees. Like the 'unsinkable' Titanic, the spreader on this kite was designed to be unbreakable. Shorter and stiffer and cunningly reinforced where it bends the most. It broke. :-(
Never mind, there will be a small design change now, to make the spreader even stronger, without adding much weight. But really, the Dowel Delta kite had already proved itself to have a very satisfactory wind range. Sometimes, the weather gets you anyway!
The Windtronic wind speed meter, in its somewhat sheltered spot on the ground near the trees, showed an average of 1.7 kph, and a maximum gust of 7.7 kph. However, I think the kite was hit with well over 20 kph when it failed. It will only take minutes to make a new spreader, since no gluing is involved.
The story or stories above document actual flying experiences.
My write-ups are definitely warts-and-all since things don't always go totally as planned. However, half the fun of kiting is anticipating the perfect flight. When it happens, it's magic!
As mentioned earlier, there's more kite-making info here than you can poke a stick at :-)
Want to know the most convenient way of using it all?
The Big MBK E-book Bundle is a collection of downloads - printable PDF files which provide step-by-step instructions for many kites large and small...
Every kite in every MBK series.