TM 1-1520-238-23
Change 1
5-99
5.19.
MAIN ROTOR HUB RETENTION NUT REMOVAL – continued
5.19.6. Repair
a. Light surface corrosion and scratches shall be removed by hand sanding using a very fine abrasive
mat. Use mat (item 122, App F).
WARNING
Repair by blending is limited to one time repair.
b. Pitting corrosion and nicks, scratches, and gouges shall be removed by hand sanding.
(1) Blending area should be ten times bigger than depth of pitting.
(2) Polish and blend rework areas with abrasive mat. Use mat (item 122, App F).
c. After removal of corrosion pits and scratches, inspect area with a x10 power glass to ensure no
evidence of imperfections remains.
(1) Repeat step b until imperfection is removed.
d. If the maximum material removed during repair exceeds 0.030 INCH, replace part.
e. Clean repaired area. Use methyl ethyl ketone (item 124, App F) (para 1.47).
f. Touch-up finish by applying two coats of epoxy primer to repair area. Use epoxy primer coating kit
(item 78, App F).
g. Coat part with corrosion preventive compound. Use corrosion preventive compound (item 63, App F).
h. Inspect (QA).
END OF TASK
