Status Report #12
That report is about
- Assembling the wing.
- Flaps, Ailerons - to control the airplane.
- Leading edge polishing.
- Aileron actuation - almost touching the control stick.
The wing assembly structure is pretty simple once your preparation
is done carefully. What I described in the previous post was our idea how to
prepare all the aluminum for the assembly up front; then eventually, we
had many pieces of metal coated in toxic yellow. So what we had to
do from here was to keep focus and no to follow our temptation to
finish quickly. The rivet counter was not stopping, and at the end
of that post we passed 9000 rivets. But let's put it down step by
Once you have the match drilling: done, countersink: done, dimpling: done
and eventually anti-corrosion coating: done, you have to find the right
orientation of the main ribs and rivet them onto the main spar. The
spar is a pretty vast bulk, so you have to use bolts additionally to
rivets to hold the main ribs on the place. It is once again inspired us:
how such a delicate piece -- as an aluminum rib -- can form that
surprisingly strong and light construction.
Section 16: installing the top skins. It is funny, but because we usually
have the wing lying upside down, those skins are really bottom skins for
us. But the real bottom skins -- we will keep them open for a while. A
better access for all parts of the wing seems pretty important here.
- Flap structure
Nose ribs, main ribs and the hinge brackets -- these guys are pretty
impressive. The hinge brackets are designed to stand out extensively,
so they make a very dramatic whole wing cord change. The most
challenging part of the flap construction was to rivet the 2 skins --
the top one and the bottom one. Especially the second skin, 'cause
you never have a good gap to insert your hands and control the backing
- Gordon visit
We had a very cool guy who pitched up in our garage. Gordon (@Waiex-guy)
appeared in our place and told us some pretty interesting stories about
flying in the army, flying in business jets, and flying pretty much
everywhere except Israel -- cause our authorities asked him to do
all the theory exams one more time before he could rent a plane.
Fortunately, we don't make a test for a person's riveting expertise, and
another pair of hands is always valuable, so we jumped directly into the
work on the flap.
Cheers, Gordon! Come back whenever you are around!
Wet riveting is already a pretty common thing. For finishing the flap
it is suggested to wrap the edge with some pro-seal. I guess the
reason, as always with control surfaces, is cracks prevention.
At first glance, an aileron is just a shorter form of a flap, but it is
not that simple. It has its special parts and pitfalls.
- aileron structure
The common parts of all control surfaces are nose ribs and main ribs.
The aileron is pretty much following that pattern and working it out
makes no problem. But the counterbalance pipe -- that looks pretty
harmless -- appears to be not that easy to install.
- counter balance
The first problem is that you have to drill the pipe precisely using
the stand drill. It is not that simple task, cause the pipe is very
tough stainless steel, it is rock hard, much harder than the soft
aluminum. Second -- you have bolts that would hold the pipe on the
ribs, and the chance to make a mistake there is pretty high, and if you
didn't do the work correctly there, you have no chance to insert the
pipe into the nose skin.
- Leading Edge (Section 22)
The leading edge has 7 large ribs -- which are pretty much the leading edge
ribs of the whole wings. It was the first time we had to paint it with black
color, so the nasty yellow wouldn't be visible through the light leans.
The light leans gig is a really challenging task to make it match the light
hole. After ~8 hours of cutting and fitting, it started to look like a part
of a real wing.
We got pretty cool and professional lights for the leading edge. Will
tell about the internals in a special post about our wings.
Section 23 is dedicated to the aileron actuation. The general idea is to
assembly 2 push rods, and connect them with a provided bell-crank. The
torque tube -- the part that will be connected to the actual stick
eventually -- should be carefully measured to be twisted in a precise
angle. That is why we had to put together a 25 mm spacer block.
Eventually, not a big deal -- still have to wait for the fuel tank to
be done -- to connect the actuation directly in the place.
Don't forget: the airplane has two wings, so once job on the first one
is done, it's better to push forward and do it one more time.
It took us about 100 hours of 2-people work on the main section,
the ailerons, the flaps, the leading edge and all the pushrods, and
leans cuttings. The wings are now looking like real wings but there
is more work to do, and we will tell you all about it.