Piper Navajo PA-31 Service Manual page 117

PIPER NAVAJO SERVICE MANUAL
3. Remove the access panel to the aft section of the fuselage. Block the elevator and rudder
trim cables ahead of the main spar and in the aft section of the fuselage to prevent the cables from
unwrapping at the trim drums. Refer to Figure 4-3. Disconnect the elevator and rudder trim cables between
stations 274. and 318. and draw the cables forward through the main spar. To allow the cables to be drawn
through the fuselage, remove the cable guard at station 244. and rub blocks at station 174. and 215.
4. Block the aileron trim cable at the side fuselage and within the wing to prevent the trim
drum from unwrapping. Disconnect the trim cable turnbuckles at wing station 90. and draw the cables
inboard through the wing. Remove cable guard at butt end of wing and tape cables out of the way at the
fuselage.
5. Disconnect the hydraulic lines that runthrough the spar at stations 112. and 144. and draw
the lines back through the wing spar.
6. Disconnect the heater air duct, heat control cable and antenna cables that lead through the
spar.
j. At station 174. disconnect the flap control cable from the actuating motor and bulkhead and
draw the cable out through the fuselage.
k. Through the wingfairingaccess opening at the under side of the wing, disconnect the fuel line
that is routed through the main spar and pull it back through the spar. Disconnect the hydraulic and fuel
lines at the exposed fittings and control cables from fuel valves.
1. Through the access openings at the wing leading edge and butt, disconnect the engine
instruments, vacuum, fuel and hydraulic lines. Remove support blocks and clamps.
m. Disconnect electrical wire connectors.
n. Draw engine control cables back through the firewall, engine nacelle and wing.
o. Arrange a suitable fuselage cradle and supports for both wings.
p. Remove the brace assembly that the fuel selector attaches to and lay forward. Unbolt and remove
the angle support(s) that extend through the spar.
q. To the side of the fuselage, at the top of the main spar, remove the fore and aft lower support
fittings. The upper fitting may remain in place.
r. Also to the side of the fuselage, at the bottom of the main spar, remove the support bolt
assembly and spacer bushing.
s. Unbolt and remove the vertical spar splice channels.
t. Unbolt and remove the upper and lower horizontal spar cap splice plates.
u. Remove the bolt assembly that attaches the front spar and fuselage fitting.
v. Remove the bolt assembly that attaches the rear spar and fuselage fitting.
w. Pull the wing directly and slowly away from the fuselage, allowing lines, cables, etc., to follow.
4-25. INSTALLATION OF WING. (Refer to Figure 4-5.)
a. Ascertain that the fuselage is positioned solidly on a support cradle.
b. Place the wing in position for installation, with the spar end a few inches from the side of the
fuselage and set on trestles. Turn out the three adjusting screws that draw the bottom fairing against the
wing butt.
c.
Prepare the various lines, control cables, etc., for inserting into the wing or fuselage when the
wing is slid into place.
d. Slide the wing into the fuselage (It may be necessary to insert a metal strip between the fillet
fairing and wing butt so as to funnel the wing between the upper and lower fairings) and butt the spar ends.
(Maximum distance of 1/32 of an inch is permissible between spar caps.)
e. Install the bolt that attaches the rear spar and fuselage fittings.
f. Install the bolt that attaches the front spar and fuselage fittings.
Reissued: 10/12/79 STRUCTURES
1E21