Hanging the Airplane Wings
Hanging the airplane
wings on my RV-8 was
one of the most exciting
days in the construction. With
on, it actually looked like an airplane instead of just parts of one. It takes a little doing to
get the holes
lined up and bolts in, so you will want to remove and re-install the
few times as possible.
very important. Make
sure you have
everything ready before you start.
you ready to make the fairings? What
about the fuel and vent lines? If
pitot line pokes out of the wing, have you drilled the hole in the
it? You don’t want
to get half way
through hanging the wings just to find out they have to come back off.
I did most of the work on
fuselage with it sitting on a
pallet. This put it
at the right height
for me to easily reach inside. But
initially fit and drill the airplane wings, the crate was too low. I couldn’t get underneath
to drill the holes
for the center bottom skins. I
shipping crate Vans used to send me the weldments.
I put a couple short 2x4s across the top to
put the weight of the fuselage on the sides of the crate instead of
just on the
thin plywood top.
You need to ensure the
level in both
directions. Use a
level across the
center spar section, and on the rear deck if you haven’t already
tail, or on the F-887 upper longeron at the canopy rail.
Mark the holes you left
open on the
inboard edge of the
bottom wing skins by drawing a line from the holes outboard. Mark 3” up the line from
the hole. Once you
have the wing in the fuselage, these
marks will help you locate the hole as you drill through the center
I used four hardware
store bolts that
were tapered on a
grinder to help align the holes and four more as temporary bolts to
airplane wings during the initial fittings. A
liberal dose of general-purpose grease on the wing spars, and on the
tapered and regular bolts, made everything slide a lot easier.
As you install the wing,
the wing spar a little
above the lower skin so that as you push it into the fuselage, the
of the spar doesn’t scrape and mar the inside of the skin.
I had help holding the
was inside the
fuselage, inserting the pins. I
with one of the tapered pins in a top hole.
Once it went all the way in, we rocked the
wing up and
down until a
lower tapered pin went all the way in.
Then I used the hardware store bolts to drive
pins out, at
the same time, leaving the bolts in the holes.
After both wings are in,
the fuselage is still
I started the wing
dropping four plumb lines
from the front of the wings—two from the wing tips, and two at the wing
(this means the tanks have to be installed.)
Then I ran another line a few inches above the
anchored on two
car jacks. I placed
one jack next to the
outboard string on one wing, then pulled the string tight and lined it
the drop line on the other wingtip.
let me see which way I needed to move the airplane wings.
I pushed the rear wing
into the fuselage and
used small C-clamps to hold them.
realigned the plumb lines and the string across the floor. I repeated this until I
had all four plumb
lines just barely touching the aft side of the horizontal string. This put the airplane
line, but didn’t assure
the line was perpendicular to the fuselage centerline.
To get everything
measured from the
intersection of the top wing skin and the forward skin at the wingtip
center rivet on the top of the turtle deck. I divided the total
the two measurements in half. I
the wing that was farther forward aft by half the measurement, and
aft wing forward by half the measurement.
Then I rechecked the four
plumb lines. After
this, minor tweaking
was required until
I got all four plumb lines just kissing the horizontal line, and the
measurements within 1/32 of an inch.
book says ½ inch difference is ok, as long as the wing sweep of both
airplane wings is
the same. I think
that any error you
leave in here will create drag and cause your plane to fly slower. The extra time spent
realigning and checking
until you get the measurements as close as possible is well worth it.
Before you start setting
incidence, make a mark on
the aft side of the F-806D and the W-807D rear spar to show proper
that when you
unclamp the C-clamp, the wing will move back in or out, and all your
hard work will be lost. Make
the mark so
you can easily slide the aft spar in or out as required to get back to
Now set the incidence on
each wing by
pushing the aft end up
or down as required. Here
is where that
mark you made on the rear spar comes in handy.
I used the shim and level measurement as
depicted in the
plans. But I also
checked that the flap fit nicely
to the bottom of the fuselage.
had set the incidence with the shim and level, I installed the flap and
that with the flap in the trail position, the bottom skin lined up with
belly of the fuselage. The
be a little off of the perfect 1/2° positive angle; the
important thing is that both airplane wings
have the same incidence.
Go back and recheck all
measurements before you
drill the hole in the rear spar. This
the last chance to make any changes.
the Rear Spar
warning in the plans is why I
suggested you don’t remove
any metal from the F-806 rear spar parts when you put the Seat
Assembly together. I
of marks and re-measured a bunch of times before I drilled this hole. I really wanted to make
sure I had edge
distance. I drew
lines on the F-806 that
were 5/8” from the edge. Then
lines for the edge of the W-807 and 5/8” from it.
That gave me a little “box” that had the
required edge distance from everything.
I could then drill anywhere inside that “box.”
You can use the spacer
you made for
the hole in the elevator
control horns to keep your drill square.
I have a drill with a level in the handle. I used this to ensure I
was level and a small
square to ensure I kept the drill perpendicular to the spar.
After the hole was
inserted a temporary bolt to
hold the position.
Removal of Wings
The bottoms of my W-807s
too far, and were
interfering with the lower skins.
marked the bottom edges of the F-806s on the W-807s and removed the
airplane wings. Then
ground off the extra metal so the
W-807 would be flush with the bottom of the F-806.
I then smoothed and primed the W-807s. This left a lot of metal
chips stuck to the
old grease on the main spars. It
lot of work to clean them up. I
suggest wrapping them with some old plastic bags during the grinding
everything is blown off, you can remove
the plastic bags and the greasy main spars are ready to be inserted in
Skin Holes and Tank Attachment Bracket
Those lines you made on
wing skins come in handy
now to locate the holes that need to be drilled.
Because you are drilling them larger than the
pilot holes, if you miss the dead center a little, it is OK.
you make the F-863 attachment
brackets, don’t remove
all the metal on the fuselage side until after you drill the two holes. It would be very easy to
remove too much
metal now, and then not have edge distance after the holes are drilled.
At this point, I made all
and vent lines to connect
the tanks to the fuselage. But
the mistake of leaving them in place when I drilled the fairings, and
one of the vent lines with the drill bit.
Be careful, or be smart enough to remove them
before I removed
But I waited until the
next time I
hung the wings (for the
final time) to rig
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