September 3, 2008 20:50 - Rokkaku Kite - In-flight Structural Failure!
Today Aren and I headed out intending to fly the 2-Skewer
Rok, since the breeze seemed fairly gentle around our house. However, by
the time we had parked at the Wilfred Taylor Reserve, it was obvious
that the breeze was probably too fresh for the Rokkaku. Hence it was a
good thing we had brought the 2-Skewer Barn Door as a backup! After
putting Aren in the pram and attaching the 150 meter line, we headed out
to near the center of the main grassed area.
The 2-Skewer Barn Door kite went up in what was a perfect wind
strength for it. Very soon, it was flying steadily with 100 meters of
line let out. At this height, the breeze was a bit stiffer. There were a
couple of forced landings when the breeze was strong enough to force
the barn door into diving to the left. Then, all of a sudden, I noticed
that the kite was heading way off to the right. Lower and lower it got,
going sideways through the air like a fish slowly swimming across its
fish tank! Strange, I thought, it should correct any moment now, and
head back towards the center. But it didn't, finally taking a dive into
the car park. It missed my car and another parked car by just a few
This is yet another incident that brings home the truth that
it doesn't matter what you think your skills are like, and how reliable
the kite has been in the past, you always have to assume it could go
down unexpectedly! In this case, I probably had 4 or 5 too many meters
of line out to be totally sure of staying out of trouble.
On a close look, I first noticed a big wrinkle in the sail
near the top of one of the diagonal spars. My first thought was that the
spar was damaged from the fast dive into the ashphalt. But it wasn't
that bad, since it was just the electrical tape spar cap that had come
loose. Somehow, the tail was still attached by sheer friction. I slid it
back up the spar a centimeter or 2 and re-attached the tape, pulling
the sail tight. Wonderful stuff electrical tape, it re-sticks so well!
Just as a precaution, I also moved the towing point forward a bit since
the wind was now quite fresh.
After this mini-drama, we had fun flying the Barn Door on 100
meters of line again, from the center of the main grassed area. Getting
bored with this, I decided to move much further upwind. The Barn Door
coped with the wind speed plus the pram towing speed quite well...
On the other side of a large grassy hump that defined the
edge of the main area, we stopped and parked the pram. I started letting
out line, and each time I stopped, a little voice would encourage me to
let out a bit more :-) So, the kite ended up flying on close to its
full length of 150 meters of 20 pound line. Straight downwind, there was
plenty of room, but there was not nearly so much on either side, so I
was prepared to run quickly cross-wind in either direction if the kite
got in trouble again.
With the wind stronger than the ideal for this kite, it was
maintaining about a 45 degree angle from the horizontal. Although there
was a fair amount of tension in the line, there was still a fair amount
of sag due to the sheer length of it. There was some thermal activity
around, but generally, the wind was much less gusty than usual. Hence
the barn door just hung up there, slowly shifting this way and that, and
gaining or losing height as patches of rising air came through. The
East South-Easterly breeze was quite cold, by Adelaide standards anyway!
I encouraged Aren to hold the flying line a few times.
However, the tension was a bit much for him due to the wind strength. It
wasn't much fun for the little tacker on this occasion! It was time to
In order to stay close to the pram with my young son, I tried
a new technique to bring the kite down without winding the line on
under tension. All I did was drop the winder and bring the line in
hand-over-hand, laying it out on the grass in the cross-wind direction.
After laying down line like this, going across and back several times,
the kite was down and I was never more than 10 or 15 meters from Aren.
After laying the kite on its back, with its tail tucked under the
trailing edge to keep it stuck on the ground, I wound all the line onto
the winder. Then it was time to go back to the car.
Aren had been demanding the Rokkaku earlier, so I thought I
would give it a try even though the breeze was rather fresh. I think
it's his favorite kite right now! Sure enough, the Rok just couldn't
cope, distorting horribly in the stronger gusts and looping into the
ground. Never mind, at least we flew something today...
September 6, 2008 20:57 - Barn Door Kite Flies Low For The Camera
This won't be one of our longer posts, since we just dropped
in briefly to the reserve near the school in Old Reynella to get some
video footage of the Barn Door kite. First up, I just put it up for a
couple of short flights on just a few meters of line. This wasn't very
satisfactory because it kept landing in the lulls! Light and variable
winds at ground level.
However, a 3rd flight on maybe 25 meters of line or so was
more successful, and it gave me 50 seconds or so of footage from which
to edit out my standard 20 second clip for the Web page. At this line
length, I had to zoom in to almost 4x to get the kite and its tail to
fill enough of the viewfinder. As you can see in the video, the kite
came down in a lull but then began to climb again in the next gust.
No-one was flying it, I just had the winder under my foot in the grass!
The weather was sunny even though the air was cool. With
cumulus clouds popping in the distance, and particularly over the hills
to the East, I expected conditions to be rather 'thermally' higher up.
Surprisingly, when I let the Barn Door right up to about 300 feet
altitude, the air was glassy smooth! The towing point was a touch too
far back, so the kite never got much above a 45 degree angle or so, but
it was a unique experience to see it just sitting there, drifting just a
little left and right with changes in the wind direction. Smooth winds
around here are rare, even in Winter.
After a relaxing few minutes of flying the kite up high, it
was time to leave, so I gave my wife the task of winding on line.
Meanwhile, I pulled the kite down hand-over-hand so the line went onto
the winder without any tension. With the kite at about 10 meters away,
the soft rustle of the black garbage bag tail was just audible. To me
anyway - I'm sure my little 2 1/2 year old Aren heard it much sooner!
The next video to go up will probably be of the 2-Skewer
Delta which I'm just designing and building right now! Could be a few
September 16, 2008 16:57 - New 2-Skewer Delta Kite - 90 Degree Line Angle!
Well, briefly, as a patch of rising air came through of
course! But it was a nice moment after taking the delta out for the
first time, and seeing it go directly overhead on 50 meters of line. We
were at the reserve near the school.
These deltas can be fussy if the design isn't quite right, so
I was pleased that it behaved itself reasonably well. Mind you, it
needed a short length of tail to cope with the gusty air. We were hoping
for another tail-less kite after achieving this with the Rokkaku. I
still think this design is capable, but it needs a bit more dihedral, a
lighter sail and smooth light winds. We'll try all that one day.
The conditions were a bit odd. Dead calm periods at ground
level, with very fresh gusts above 50 feet or so! Enough to move medium
sized branches around. Also, large variations in wind direction. Well,
that has to be thermals doesn't it. Indeed, while the kite was out on 50
meters of line and climbing high, a small soaring bird appeared and
began to thermal upwards. The bird approached at perhaps 3 times the
height of the kite, but then climbed much higher towards the thick gray
cloud cover overhead, slightly downwind of the kite.
I enjoyed a few minutes of seeing this latest creation doing
its thing, against a backdrop of thick cloud and hazy blue patches.
Sometimes, the delta struggled in the stronger gusts, porpoising rapidly
up and down as it strained against the wind and picked up speed.
Actually, I once saw the kite do this from behind its tail, while my
wife did the flying far upwind of me. The kite was flapping vigorously!
Not just the trailing edge, but the entire wing was flapping like a
bird! A few times the orange delta was forced into a wide loop or long
dive. It was fun to release tension on the line, see the kite stabilize
itself immediately, and settle into another long climb back up.
Everything that happened today backed up what I read
somewhere about single-line deltas - the best wind speed to fly them is
just strong enough to get them climbing. Also, deltas always go unstable
with too much wind speed. For a home-made delta with a slightly heavy
sail (like this one!), this adds up to a somewhat limited wind range.
But when conditions are right, you can still have hours of fun!
September 18, 2008 20:56 - 2-Skewer Delta Breaks Altitude Record
Well, it's own altitude record that is, and that wasn't hard
since it's previous flight was the first test flight! Anyway, it was
great to see the orange 2-Skewer Delta soaring around high up in gusty
air with the occasional thermal boost. On arriving, we made our way to
near the center of the Wilfred Taylor Reserve, since I wasn't clear on
the wind direction. It seemed to be mainly from the West. The hand
launch was super-easy, with the delta going up steadily like a lift.
Line flew off the 150 meter winder, as I regulated it between finger and
thumb. No need for a glove since this kite doesn't have a lot of sail
Once the kite was well above tree height, we started slowly
moving backwards upwind, letting more line out. Soon there came this
freakishly strong series of gusts, and the poor delta just couldn't
cope. It ended up on the ground after narrowly missing some trees. In
fact it disappeared altogether, since it was on the other side of a hump
near the edge of the reserve. Just before it landed, I noticed the
entire line of trees just behind it were being battered with very fresh
wind. Where we were standing, less than 100 meters away, there really
wasn't much happening at all! The kite must have copped the edge of the
biggest thermal of the hour.
Pulling the line taut, I dragged the kite into view and stood
it on its nose, waiting for a break in the wind. When the break came,
it was fairly easy to flop the kite forward on its face, swivel it into
wind with another pull on the line, and then pop it off the grass and
into a long, fast climb back up to 50 meters or so.
After this, we continued moving upwind until finally we were
right at one edge of the reserve. It became clear that the wind
direction up high was more from the south, which was a bit inconvenient
since it gave the kite less room. I was flying basically across the
width of the reserve rather than down its considerable length. For this
reason I wasn't able to safely let out all 150 meters of line. I guess
about 120 meters were out.
The kite was still encountering wind that was a bit strong
for it from time to time, so it covered a lot of sky. Several times it
went into a vertical dive until slower moving air gave it a breather and
let it recover. Most of the time however, the delta flew smoothly,
between 50 and 60 degrees of line angle. Remember, this is probably the
smallest 2-skewer kite, flying on more than 100 meters of line which had
a fair amount of sag in it.
A bit of thermal assistance did pump the kite up to around 75
degrees at one point. Cool! It meandered around lazily, gliding like a
paper plane for a while, before drifting back downwind. Eventually it
was time to leave so I brought the kite down in stages, winding onto the
winder in periods where the line tension was low.
An enjoyable flight! Makes me keen to start on a bigger delta sometime...
September 22, 2008 13:32 - Tree Leaps Out And Grabs Delta Kite
But it wasn't all bad! Read on... After going for a walk
beside the sea at Glenelg, we were going to fly a kite from the beach,
late in the afternoon. However, the tide was in and the only sandy
stretches had too many people to safely fly at any reasonable height.
Actually, we did see a couple of kites flying. A small sled and a fairly
small diamond. Both colorful and, I'd say, shop bought. They were
flying at less than 10 meters off the sand, which was sensible
considering the number of people around.
However, it's just occurred to me that we probably fly our
MBK kites much higher than most beach goers fly theirs. If you read this
blog much you'll know my liking for nudging the legal altitude limit as
often as possible!
We had no idea what the wind was going to be like, so had
brought along three 2-skewer kites to cover all wind speeds. The Sode
for very light breezes. The Delta for light to moderate. The Barn Door
for moderate to fresh. Nothing will stop the flying!
We got around the lack of beach space by just dropping in at
one of our regular flying spots on our way back home. The reserve near
the school in Old Reynella. I walked out to near the middle of the field
and attached the 150 meter line to the Delta. The kite of the month and
therefore the favorite! There was very little breeze down low, but it
wasn't hard to urge the Delta up a bit higher where it started to
contact a smooth Northerly breeze. Just like down at the beach.
Quickly, I had more than 100 meters of line out and the Delta
was doing fine, although showing signs of being near the top of its
wind range. Yep, the breeze was rather fresh up there around 70 - 80
meters above ground! The Delta pulled very firmly on the 20 pound nylon
line, and finally started to lean way over to the right. Mmmm, those
trees could be a bit close... Ummm kite diving... better... pull in
line... RIGHT NOW pulling, pulling... ooops too late! At least I started
pulling in early enough so that the kite flew into the upwind side of
This is an honest blog. After all my preaching about making
sure there is room in case of the unexpected, what happens... I fly the
Delta into a tall tree on its 3rd outing! Bother, blast and other mild
OK, what's done is done. I tugged at the line to see if the
kite would just pop out. Nope. Reeling in most of the line, I approached
the tree and tried another angle. The kite slipped down, and it was
clear the line was around a single small twig. I pulled hard, expecting
to break something, but thankfully the twig snapped and the kite floated
down in one piece!
Soon the Delta was in the air again, and I backed off right
into the far corner of the field to avoid a repeat performance. Even
this time, I didn't get all 150 meters of line out since the wind was
too fresh up high. Once or twice the Delta did an enormous loop to the
right before recovering. However, it was flying with a tail that was
only twice the length of the kite itself, so that was pleasing.
With all the tension in the line I decided against just
winding it straight on. Instead, it was easy to walk out to the kite,
bringing down the line as I went. With the kite in the grass, I walked
back to the winder, wound it all on and took the kite back to the car.
So glad it wasn't lost after the drama in the tall trees!
September 29, 2008 10:29 - Delta Kite Rides Gale Without Tail
OK, 2 slight exaggerations there. Hey, it rhymed! Firstly,
the breeze was blustery and fresh, down at the Holden Hill reserve off
NE Road. Not quite gale force though. Secondly, I experimented with
removing a loop of tail plastic. This left the 2-Skewer Delta with just 1
loop, which is about as long as the kite itself. Although the delta
then tended to loop tighter in some situations, it seemed pretty much as
stable as usual when flying in a patch of smooth air. I think the main
reason for this success was the small additional patches of tape I added
to the left spar, to balance the kite. (After taking it home after its
1st flying session I discovered the right wing was heavier.) Perhaps
deltas are a little more sensitive to balance in this way than diamonds
and Roks and so on.
To start with, the delta was on about 30 meters of line. It's
a small reserve, and I was still playing chicken with some of the
trees... A couple of times, gusts accelerated the kite upwind. Its
inertia carried it just past vertical! Never seen that before.
With the fresh breeze, the delta got quite a workout, often
porpoising and wing-flapping as described in earlier posts! But being
nicely balanced, it gamely managed to stay in the air for most of the
time. Actually, the leading edge spars were flexing inwards and outwards
behind the spreader. This gave the impression of flapping because the
sail would billow up and down as it went slack and then tight again. All
very quick mind you! About 5 times per second I would guess.
The couple of times the kite did end up on the ground, it was
easily re-launched from where I was standing. The usual strong-wind
technique. Pull it up on its nose, wait for a lull, topple it over onto
its face, drag the nose into wind then pop it off the deck. I quite
enjoy doing this! Sometimes you have to use a little finesse otherwise
the kite can shoot sideways and curve straight back into the ground
again. Also, if the wind is that strong, you might have to walk towards
the kite or let out line as it climbs, to keep it climbing straight.
Moving down the reserve a bit, I found some more room and let
out all 50 meters of line. Because of the wind strength, the kite
didn't get much chance to move up to a really steep flying line angle on
this length of line.
Eventually, a squall came through. First clue was a sudden
increase in overall wind speed. Then, less than half a minute later,
just the tiniest flecks of rain. Oops, time to bring the kite down
immediately. I dropped the winder and walked towards the kite, pulling
it down as I went. Amazingly, short tail and all, it kept flying at a
high angle until it was down.
After the squall passed, we pulled out the 2-Skewer Barn Door
and gave it a bit of a fly on just 20 meters or so of line. This kite
doesn't mind a fair bit of breeze. May, my wife, had a fly for a few
minutes while I watched Aren on the play equipment. No kite flying for
him today, since conditions weren't really suitable.