TM 1-1520-238-23
Change 1
6-431
6.97.
MAIN ROTOR SUPPORT MAST REMOVAL/INSTALLATION – continued
(5) Clean repaired area.
(a) Clean repaired surface of dirt, grease,
and metal particles. Use cloth (item 51,
App F) and dry cleaning solvent (item 74,
App F).
(b) Remove oil residue from dry cleaning sol-
vent. Use cloth (item 51, App F) and
isopropyl alcohol (item 106, App F).
(6) Fluorescent dye penetrant inspect repaired
surface. No cracks or deformities allowed
(TM 55-1500-335-23). Use fluorescent
inspection kit
(7) Mask off area around repaired surface. Use
tape (item 206, App F).
(8) Apply solid film lubricant. Use lubricant
(item 115A, App F).
(a) Spray uniform coating 0.0002 – 0.0005
INCH thick on repaired area. Use
lubricant (item 115A, App F).
(b) Allow lubricant to air dry for a minimum of
18 hours at room temperature.
6.97.7. Installation
a. Install lifting eye (1) on mast (2), if mast (2) is
being replaced.
(1) Attach crane hook (3) to lifting eye (1).
b. Install mast (2) on support (4).
(1) Apply a thin coat of sealing compound to bot-
tom 3/4 INCH of 18 support bolts (5). Use
sealing compound (item 177, App F).
(2) Lift mast (2) from platform, then lower in place
on support (4).
(3) Aline bolt holes in mast (2) with bolts (5) on
support (4).
(4) Wipe excess sealant from bolts (5) and bolt
holes in base of mast (2) with a clean rag.
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M04-520-2
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1
2
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SEALANT
