TB 1-1520-237-20-212
(1) If the facilities or qualified personnel to accomplish the inspection using the Eddy Current NDI
are not available, a fluorescent penetrant inspection (FPI) must be accomplished IAW paragraph 8.f. Eddy
Current NDI is preferred over the FPI procedures, as it will require fewer man hours to accomplish this task.
(2) The Eddy Current Inspection requires the SPCK-107A probe kit, detailed AVIM level instruc-
tions are included in the kit. The UH PMO is fielding one probe kit to each AVIM site that were previously
provided Eddy Current test sets issued by the Aviation Ground Support Equipment Directorate of the Deputy
for Systems Acquisition. The probe kits are expected to be available within 21 days. The instructions will
be published in TB 1-1520-237-20-212 and are also available on the safety page of the UH PMO website
(http:/www.uhpo.redstone.army.mil).
f.
Fluorescent Penetrant Inspection (FPI):
WARNING
Each step of the cleaning process must be accomplished as described in this procedure us-
ing the materials specified every time the inspection is accomplished. Not following these
procedures may result in a crack not being detected by the FPI. These procedures take pre-
cedence in the event of any conflict with TM 1-1500-335-23.
CAUTION
helicopter components/surfaces. Do not allow epoxy paint remover to enter threads of insert
in bolt hole.
NOTE
This inspection requires the use of a type 1, method C, level 4 sensitivity penetrant system.
Personnel performing this inspection must be certified level II penetrant inspections or mili-
tary equivalent.
(1) Remove all four Main Rotor Damper Assemblies P/N 70106-08100-46 and Dampener
Bracket P/N 70103-08100-048 from the Hub Assembly,
(2) Mask off an area on the inside surface of the Main Rotor Hub extending& least one-half inch
in all directions from the hole where the eleven o'clock dampener bracket attaching bolt extrudes through the
interior surface.
(3) Pack rags into the cavity of the hub arm around the elastomeric bearings of spindle and un-
derneath the arm to be cleaned to prevent epoxy paint remover from damaging components. Also place rags
or protective rubber mat under Hub Arm to prevent damage to the swashplate or related airframe surfaces.
(4) Using a small paint brush, clean area to be inspected manually applying epoxy paint remover,
MIL-R-81294, Type 1, Class 1. If paint is present allow paint remover to remain on surface until paint
bubbles, Gently remove paint coatings using rags, wooden or plastic scrapper. Remove all remaining epoxy
paint remover using a rag saturated with water. Repeat as necessary to thoroughly clean inspection area.
(5) Re-clean inspection area and threads of insert with dry cleaning solvent. Clean insert with
cotton swabs. Allow to dry 15 minutes. Re-clean inspection area and threads of insert with acetone. Clean
insert with cotton swabs.
(6) Perform fluorescent penetrant inspection on the inside surface of the Main Rotor Hub where
the eleven o'clock dampner bracket attaching bolt extrudes through the interior surface. The FPI is to be ac-
complished IAW TM 1-1560-335-23 except where modified by the following steps.
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