TM 1-1520-264-23
6.19.3.7
Marking and Recording of Inspection Results. Mark and record the inspection results as required by
paragraph 1.3.
6.19.3.8
Demagnetization. With the switch remaining in the AC position, place the probe/yoke legs in the same
position used for magnetizing. Press the test switch and withdraw the probe/yoke from the part for a distance of two feet
before releasing the switch.
6.19.4
Backup Method. None required.
6.19.5
System Securing. Clean the flight control system push-pull rods 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 flight control
system push-pull rods, if removed, require installation in accordance with the applicable technical manuals listed in Table
1-1.
6.20
NONFERROUS FLIGHT CONTROL SYSTEM P USH-PULL RODS (ET).
6.20.1
Description (Figure 6-1. Index No. 20). This is a generic inspection pertaining to nonferrous flight control system
push-pull rods throughout the helicopter.
6.20.2
Defects. This inspection is used to verify crack indications found visually on the flight control system push-pull
rods. No cracks are allowed.
6.20.3
Primary Method. Eddy Current.
6.20.3.1
NDI Equipment and Materials. (Refer to Appendix B.)
a.
Eddy Current Inspection Unit
b.
Probe, straight, shielded surface, 100 KHz-500 KHz
c.
Probe, right angle, shielded surface, 100 KHz-500 KHz, 90 °
1/2 inch drop
d.
Cable Assembly
e.
Reference Block, three-notched aluminum (0.008, 0.020, and 0.040 EDM notches)
f.
Teflon Tape, refer to Table 1-8
g.
Aircraft Marking Pencil, refer to Table 1-8
6.20.3.2
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 flight control system push-pull rods shall be removed in
accordance with the applicable technical manuals listed in Table 1-1.
6.20.3.3
Access. Refer to Figure 1-4, Table 1-2, as applicable.
6.20.3.4
Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
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