Wing Fit and Final
Aircraft Assembly
The last big job is
fitting the wings to the fuselage. We
built a wood frame with a
foam rubber top and
lifting straps. By using an engine
hoist, it made this job easy and
allowed us to make fine
adjustment as we moved the wing into position.
We removed
our fuel hatches so that
we can precisely measure the correct length to the wing. This
allowed the fuel lines
to safely float inside of the access hole while we made the sweep,
triangulation and angle
adjustments. We also wanted to make the
recommended fuel
cover modifications by
applying fuel sealant to both the sender and hatch covers to
prevent leaks in the
future.
Next, we measured the
sweep by comparing four plum-bobs on the wings over a straight line
located on the
ground. We could not believe it, but it
was perfect the very first time. In
addition,
a triangulation
measurement from tail to wing tip was accomplished as called out in Vans
Simplified Wing
Installation Guide.
The critical measurement
is the wing incident angle. The
fuselage is leveled with
respect to the right and
left longerons. If there is a
difference in level, then the two sides are
averaged together. We found both sides agreed perfectly, so we
adjusted wing incident angle
according to drawing 38
using the 4 5/64 height adjustment with respect to a wing level.
In drilling the 5/16
holes, into the rear spar, it is a good idea to make a drill guide in order
to drill each of the
holes straight. It is paramount that
you achieve 5/8 spacing between any
edge and your hole
center. We marked boundary lines and
formed an area the was safe
to drill into before
actually drilling our holes.
Now, the forward connect
points are fabricated and drilled into the wing connection points.
From hole-center, a ½
spacing between each edge is required to insure good installation.
Since the fuel line is
floating into the fuel tank now, we just marked were it went through and
measured back by the
fuel fitting length. Also, in this
picture, you can see the large main spar.
To align it, we used
greased drift pins that were made from the original bolts. We just ordered
a few extra bolts that
we make into drift-pins.
Next, the wing root gap
skirts were fitted. For the bottom pan
skirt, we used a hole finder
to precisely locate and
drill each hole. We just temporarily
installed #8 round head screws
and then dimpled them
after completing this operation. The
Flap rod hole was then enlarged
by slowly raising and
lowering the flaps. The hole actually
ends up being lager than you
think, but you need to
maintain that 1/8 spacing for the FAA (see above pictures).
