TM 1-1520-265-23
4-70
Change 2
4.29.3.6 Marking and Recording of Inspection Results. Mark and record inspection results as
required by paragraph 1.3.
4.29.4 Backup Method . None required.
4.29.5 System Securing . Clean the parking brake valve components to remove inspection media.
Refer to Post Cleaning and Restoration of Part or Area After NDI, paragraph 1.4.16. The parking
valve requires assembly and installation in accordance with the applicable technical manuals listed
in Table 1-1.
4.30 SLAVE MIXER VALVE PARTS (PT).
4.30.1 Description (Figure 4-1, Index No. 30) . The slave mixer valve isolates the pilot and copilot
brake line circuits from each other. This inspection pertains to the components contained within the
slave mixer valve body.
4.30.2 Defects . This inspection is used to verify crack indications found visually on the slave mixer
valve components. No cracks are allowed.
4.30.3 Primary Method. Fluorescent Penetrant.
4.30.3.1 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.
4.30.3.2 Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance
and the slave mixer removed and disassembled in accordance with the applicable technical
manuals listed in Table 1-1.
4.30.3.3 Access. Not applicable.
4.30.3.4 Preparation of Part. Refer to Preparation of Part or Area for NDI, paragraph 1.4.4.
4.30.3.5 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 4-30.
4.30.3.6 Marking and Recording of Inspection Results. Mark and record inspection results as
required by paragraph 1.3.
4.30.4 Backup Method . None required.
4.30.5 System Securing. Clean the components to remove inspection media. Refer to Post
Cleaning and Restoration of Part or Area After NDI, paragraph 1.4.16. The slave mixer valve
requires assembly and installation in accordance with the applicable technical manuals listed in
Table 1-1.
