SECTION 8
THE FUSELAGE
RV-8/8A
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8s8PP-1 r1 06/23/11
1 Fwd Floor Panel to remove powder coating and correct any misalignment in the holes (See DWG 75).
Repeat the previous step for the two 1/4-inch bolt holes (final-drill 1/4) in each WD-813 L.G. Bolt Weldment.
Place the fuselage inverted on saw horses and adjust its position so the forward center portion of the F-822-1
Forward Floor Panel is level laterally and longitudinally.
File a small radius on the corners of the U-801-L & -R Gear Legs so they nest flush in the U-804 Inboard Main
Gear Attach Brackets.
Nest the U-804 Inboard Main Gear Attach Brackets tight to the U-801-L & -R Gear Legs and clamp in position
(See DWG 75).
Use a drill press to match-drill 7/16 each U-804 Inboard Main Gear Attach Bracket using the 7/16 hole in the U-
801-L & -R Gear Legs as a guide. Use a slow drill speed, drill lube (Boelube
¥
available from Van’s), and
plenty of pressure.
Label the U-804 Inboard Main Gear Attach Brackets (left or right as appropriate) to identify which U-801 Gear
Leg they are common with. Remove the inboard main gear attach brackets from the gear legs. Install tempo-
rary 5/16-inch bolts through each inboard main gear attach bracket and a U-806-1 Inboard Wear Plate, to hold
them in alignment relative to each other. Use a drill press to match-drill the 7/16 hole, drilled in the inboard
landing gear attach brackets in the previous step, into the inboard wear plate.
Install the U-801-L Gear Leg, U-804 Inboard Main Gear Attach Bracket, U-806-1 Inboard Wear Plate, and U-
805-1 Outboard Wear Plate onto the fuselage using only the 7/16 bolt, nut, and washer. Repeat this step for
the right gear leg and related parts.
Fit the U-803 Outboard Main Gear Attach Brackets to each gear leg. Position them as shown in “View A-A”,
DWG 75. File the F-850-1 Bottom Skin and F-851-L-1 & -R-1 Fwd Bottom Skins slightly if they interfere with the
corners of the main gear attach bracket.
Insert a temporary 3/8 bolt in each U-803 Outboard Main Gear Attach Bracket and U-805-1 Outboard Wear
Plate pair to maintain their alignment with each other.
Attach two plumb lines from the leading edge of the U-801-L & -R Gear Legs (one at the outboard end and one
near the inboard end of each leg). Attach one plumb line through the center tooling hole of the F-812-1 Bulk-
head Assembly.
Re-position the U-801-L & -R Gear Legs so that the four plumb lines on the gear legs are in alignment with
each other when checked with a taught string line or long straight edge on the floor. Make the distance from
the outer plumb line on each gear leg to the plumb line at the F-812 Bulkhead Assembly equal within 1/4-inch
when measured along the floor. Adjust the position of the two gear legs as required.
Draw a pen line on the F-822 Forward Floor Panel next to each gear leg so that accidental movement of the
gear legs from their proper position will be evident. With the gear legs in proper position, tighten the nuts on
each 7/16 bolt to prevent the leg from moving out of position.
Double check that the U-805-1 Outboard Wear Plates and U-803 Outboard Main Gear Attach Brackets are still
properly located as shown in “View A-A”, DWG 75.
Using the forward hole in each U-803 Outboard Main Gear Attach Bracket as a guide, drill a 3/8 hole through
the F-822-1 Forward Floor Panel, F-843-L-1 or -R-1 Lower Longerons and left or right WD-822 L.G. Box Weld-
ment. Insert a bolt into the drilled hole to hold position, then drill the aft hole location in each outboard main
gear attach bracket into the fuselage structure and insert another bolt.
Use the 5/16 holes in both of the U-804 Inboard Main Gear Attach Brackets and U-806-1 Inboard Wear Plates
to Match-Drill 5/16, the holes in the F-822-1 Forward Floor Panel and the WD-813 L.G. Bolt Weldments. Drill
one hole in each inboard main gear attach bracket, insert a 5/16 bolt to maintain position, and then drill the
other hole.
With at least one 5/16 bolt still in place from the previous step, match-drill 1/4 the hole in the WD-813 L.G. Bolt
Weldments into each end of the U-806-1 Inboard Wear Plates.
RV-8 Quick build Fuselage Only:
Final-Drill 1/4 the drilling access holes in the F-850-1 Bottom Skin and F-
851-L-1 & -R-1 Forward Bottom Skins (See “Installing the Bottom Skins”, DWG 75).
RV-8/8A
SECTION 8
THE FUSELAGE
8-44
8s8PP-1 r1 06/23/11
Match
-
Drill 1/4 the F-822-1 Forward Floor Panel, F-843-L-1 & -R-1 Lower Longerons, and F-822-L-1 & -R-1
L.G. Box Weldments using the hole at each end of the left and right U-805-1 Outboard Wear Plates.
Remove gear legs, brackets, and wear plates from the fuselage. Deburr all drilled holes in the fuselage, wear
plates, and brackets.
A finished RV-8 stands tall when it's on its wheels. The exact "best time" to permanently mount the landing gear will
depend on the exact assembly sequence you choose, available help and workspace, etc. Don't be in a hurry to get
it on the gear -- we have found it much more convenient to keep the top longeron of the fuselage at "navel height"
until all the fwd upper fuselage, canopy installation, instrument panel, engine controls, and other interior fuselage
work is complete.
Return to this point in the landing gear installation section when you are ready to permanently install the landing
gear.
Install the U-801 landing gear legs. Refer to DWG 75 for the correct landing gear attachment hardware. The
gear leg openings in the U-803 Outboard Attach Bracket and U-804 Inboard Attach Bracket are designed
smaller than the nominal gear leg thickness. This will cause a 1/32-inch (approximate) gap between the out-
board attach brackets and their associated F-805-1 Outboard Wear Plates, and the inboard attach brackets and
their associated F-806-1 Inboard Wear Plates when all the nuts have been properly torqued.
NOTE: Hardened
3/8-inch washers are used under the nuts on the bolts used for attaching the U-803 Outboard Attach
Brackets to the fuselage. Refer to “Landing Gear Installation”, DWG 75 for specific hardware part des-
ignations.
When tightening the nuts on the NAS bolts that attach the U-803 Outboard Attach Brackets to the fuselage, a
socket can be fitted to the nut with the use of a universal joint, and an assortment of different length extensions
to allow the torque wrench to be located outside of the L.G. Box Assembly. Tighten the nuts on each outboard
attach bracket by first hand-tightening each nut until it just contacts the washer, then alternate between them,
tightening in 5 in./lb. increments until reaching the final torque of 240 in/lbs. This will leave a gap of approxi-
mately 0.030-inch between the face of each outboard attach bracket and the U-805-1 Outboard Wear Plates.
CAUTION: DO NOT over tighten these bolts. Doing so will bend the outboard attach bracket and actu-
ally weaken the assembly. Check these bolts and re-torqued after the first ten flying hours, then again
at 50 hours, and annually thereafter. Failure to do so could lead to premature wear. The consequences
of a loose gear leg are easy to imagine.
If you put the proper torque on the bolts and there is less than the
required .030 gap, then file or machine the faces of the outboard attach bracket until the correct gap is ob-
tained.
Torque the remaining landing gear attachment bolts to the standard values for each bolt size and nut type.
Trim the outboard end of the F-866PP-L & -R Landing Gear Cover Plates as needed to provide clearance to the
U-801-L-1 & -R-1 Gear Legs and U-803 Outboard Attach Brackets and install them with the hardware depicted
on DWG 75.
Install the FSTS635-1 Full Swivel Tail Spring in the WD-409 Tail Spring Mount (See “Iso View”, DWG 73). Coat
the machined surfaces with grease before installing to prevent rust. Refer to “View B-B”, DWG 73 for hardware
depiction.
Install the U Tail Wheel 6-inch, WD-102 Axle With Tail Fork, and associated hardware on the WD-101 FSTW
Mount Base (See “Exploded Iso View”, DWG 73).
RV-8A MAIN LANDING GEAR INSALLATION
(This section RV-8A only)
RV-8A Quick Build Fuselage Only:
Install the U-801A-L & -R Main Gear Legs in the WD-821-L & -R Landing
Gear Weldments (See DWG 67A).
RV-8A Quick Build Fuselage Only:
Put a bolt into the 5/16-inch hole in each landing gear weldment to align
the gear leg. Remove the bolt. Working carefully to avoid disturbing the position of the gear leg, final-drill the
hole all the way through with a 7.9 mm drill bit or a .311-inch ream.
RV-8A Quick Build Fuselage Only:
Remove the main gear legs and store them for later installation.
A finished RV-8A stands tall when it's on its wheels. The exact "best time" to permanently mount the landing gear
