Install Vertical Stabilizer

TM 55-1520-238-S

m. Mount Vertical Stabilizer On Helicop-

d. Couple Sling to Crane. Connect crane

ter. Carefully swing stabilizer over tail-

lifting hook to stabilizer sling lifting eye.

boom. Aline intermediate gearbox (fan) and

Carefully operate crane winch to remove all

number five drive shaft coupling flanges,

slack from sling straps.

and center four stabilizer mounting lugs

e. Remove Stowing Fixture Aft Support

over mating tailboom holes. Install four

Struts. Remove the four strutrelease

mounting lug bolts and washers. Torque

pins.

four bolts to 900 inchpounds.

f. Raise Stabilizer. Operate crane winch

n. Remove Stabilizer Sling. Unlock and re-

and swing stabilizer up and aft to vertical

move four sling pins from stabilizer pin

position.

sockets. Unsnap fifth (tail rotor shaft loop)

strap from sling bar. Remove sling lifting

g. Install Remaining Stabilizer Sling

eye from crane hook.

Straps. Insert and lock two sling long

o. Connect Tail Rotor Drive Shaft. Install

strap quickrelease pins in stabilizer for-

five coupling bolts through gearbox (fan)

ward (bottom) pin sockets. Pass the fifth

and shaft coupling drive flanges. Torque

strap through tail rotor pitch links and

five bolts to 120 inchpounds.

around the tail rotor drive shaft. With both

ends of fifth strap on sling bar forward end

p. Connect Tail Rotor Control Horizontal

eye, remove all strap slack at the tail rotor

Pushrod. Slide pushrod aft through inter-

drive shaft, and secure the fifth strap

mediate gearbox fan shroud. Install two rod

buckle.

endtobellcrank clevis bolts, washers,

and nuts. Torque nuts to 0 to 40 inch

h. Disconnect Intermediate Gearbox Drive

pounds. Install new cotter pin (D17) at

Flange from Stowing Fixture. Remove

torqued nuts.

five coupling bolts from fixture bracket and

q. Install Tailboom Left Side Aft Step. Ob-

gearbox (fan) drive flange. Retain removed

tain left side aft step from catwalk area.

bolts.

Install two mounting bolts and washers to

i. Remove Vertical Stabilizer from Stowing

secure FS 517/WL 136 left side step.

Fixture. Remove four captive bolts from

r. Connect Vertical Stabilizer Forward and

stabilizer mounting lugs and pivoting base

Aft Electrical Wiring. Connect two elec-

frame. Operate crane winch and lift stabiliz-

trical harness plugs (P124 and P756) to

er clear of the fixture. Perform depreserva-

mating tailboom forward and aft bracket re-

tion of coated surfaces.

ceptacles; connect coaxial plug (P329) to

j. Release Number Five (Tail Rotor) Drive

trailing edge base receptacle; and, if

Shaft from Stowing Fixture. Fully open

installed, connect GPS antenna coaxial

aft fixture forward brace strap.

plug (P1304) to mating receptacle. Secure

vertical coaxial lead with two clamps.

k. Remove Stowing Fixture from Helicop-

s. Connect Stabilizer Forward and Aft Hy-

ter. Remove two pivot quickrelease pins

draulic Lines. Connect four hydraulic

and lift pivoting base frame from aft fixture.

quickdisconnect fittings at lower ends of

Remove four stabilizer mounting bolts and

stabilizer vertical structure.

washers and remove the aft fixture from

helicopter tailboom. Retain stabilizer

t. Install Lower Leading Edge Fair-

mounting hardware.

ing. Secure 23 camloc fasteners at fair-

ing (L510).

l. Seal

Stabilizer

Mounting

Sur-

u. Install

FMAM

Whip

Antenna

faces. Coat joints between stabilizer

(MWO 1-1520-238-50-37 installed). Para-

mounting lugs and tailboom with primer

graph 216.4.

(D9), and allow to dry.

276

Change 4