TM 1-1520-265-23
Change 2 6-43
6.21.4 Backup Method. None required.
6.21.5 System Securing. Clean the aft bellcrank thoroughly to remove all residual magnetic
particle media. Refer to Post Cleaning and Restoration of Part or Area After NDI, paragraph 1.4.16.
The aft bellcrank, if removed, requires installation in accordance with the applicable technical
manuals listed in Table 1-1.
6.22 HYDRAULIC/PNEUMATIC SYSTEM COMPONENTS (PT).
6.22.1 Description (Figure 6-1, Index No. 22). This inspection is applicable to all unpainted valves,
fittings, and tubes contained within the hydraulic/pneumatic system. This inspection can also be
used to verify any indications found on painted surfaces, providing the paint is only removed from
the immediate area of interest.
6.22.2 Defects.
This inspection is used to verify crack indications found visually on the
hydraulic/pneumatic system components. No cracks are allowed.
6.22.3 Primary Method. Fluorescent Penetrant.
6.22.3.1 NDI Equipment and Materials. (Refer to Appendix B.) Inspection equipment is listed in
Table 1-7. AMS 2644 level 3 penetrant materials shall be selected from the approved list in Table
1-8. Parts requiring flourescent penetrant inspection shall be cleaned prior to inspection with
n--Propyl Bromide (vapor degreasing only)(Table 1--8), DS--108 (Table 1--8), Electron (Table 1--8),
Positron (Table 1--8). DS--108, Electron, Positron must be followed by an acetone (Table 1--8) rinse
or wipe: or drying until there is no visible solvent residue left on parts.
6.22.3.2 Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance.
A partial inspection for cause (visual indications, sites of mechanical damage, corrosion, etc.) may
be performed on all exposed surfaces of the installed part using this procedure. If required, the
hydraulic/pneumatic system components shall be removed in accordance with the applicable
technical manuals listed in Table 1-1.
6.22.3.3 Access. Accessibility to the hydraulic/pneumatic system components varies considerably.
Refer to Figure 1-4 and Table 1-2 to locate applicable access provisions.
WARNING
Maintenance Platforms/Workstands
Use only appropriate platforms, workstands, or other approved locally procured
stands and restraint equipment when working above 10 feet on helicopters in a
nontactical environment. Otherwise, personnel injury could result from accidental
falls.
6.22.3.4 Preparation of Part. Refer to Preparation of Part or Area for NDI, paragraph 1.4.4.
6.22.3.5 Inspection Procedure. Perform fluorescent penetrant inspection. Refer to Fluorescent
Penetrant Method, paragraph 1.4.7 and Table 1-5. Inspect area of concern. See Figure 6-22.
6.22.3.6 Marking and Recording of Inspection Results. Mark and record inspection results as
required by paragraph 1.3.
6.22.4 Backup Method. None required.
6.22.5 System Securing.
Clean the hydraulic/pneumatic system components to remove
inspection media. Refer to Post Cleaning and Restoration of Part or Area After NDI, paragraph
