TM 1-1520-238-23
6-428
Change 1
6.97.
MAIN ROTOR SUPPORT MAST REMOVAL/INSTALLATION – continued
6.97.4. Cleaning
a. Remove old sealant from support, bolts, and spacer plate (para 1.47).
b. If mast is not being replaced, remove old sealant from bolt holes in mast base (para 1.47).
c. Wipe removed and attaching parts with a clean rag.
6.97.5. Inspection
a. Check mast attachment area for cracks. None allowed.
b. Check bolts for thread damage. None allowed.
c. Check mast for cracks, nicks, gouges, and corrosion. Use depth gage (TM 55-1500-344-23).
NOTE
The electroless nickel, cadmium, titanium, and silver plating finish applications are allowed to overlap
in the thread relief area. This condition occurs during manufacturing and is not considered a defect.
(1) Damage to threads or thread relief area only allowed to top 0.160 INCH starter threads.
(2) Damage to other areas not exceeding 0.003 INCHES deep need not be repaired. Use depth gage.
(3) Damage to all other areas exceeding 0.003 INCHES but not exceeding 0.020 INCHES deep may be
repaired. Use depth gage.
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