TM 1-1520-264-23
4.27.3.7
Marking and Recording of Inspection Results. Mark and record the inspection results as required by
paragraph 1.3.
4.27.3.8
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.
4.27.4
Backup Method. None required.
4.27.5
System Securing. Clean the main landing gear shock strut rod ends 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 main
landing gear shock strut, if removed, requires installation in accordance with the applicable technical manuals listed in
Table 1-1.
4.28 MAIN LANDING GEAR LOWER-STRUCTURAL SUPPORT (MT).
4.28.1
Description (Figure 4-1. Index No. 28)
. The main landing gear lower structural support is a boomerang-
shaped tubular part attached to the cable cutter on one end and a clamp around the trailing arm on the other. There are
two supports, one on each side of the helicopter.
4.28.2
Defects. This inspection is used to verify crack indications found visually on the main landing gear lower
structural support attachment area. No cracks are allowed.
4.28.3
Primary Method. Magnetic Particle.
4.28.3.1
NDI Equipment and Materials. (Refer to Appendix B.)
a.
Magnetic Particle Inspection Probe/Yoke
b.
Magnetometer
c.
Black Light
d.
Fluorescent Magnetic Particles, refer to Table 1-8
e.
Consumable Materials, refer to Table 1-8
f.
Aircraft Marking Pencil, refer to Table 1-8
NOTE
Hand-held magnetic coil may be used. Refer to paragraph 1.4.8.1.2 and Figure 1-6.
4.28.3.2
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 applicable positions of this procedure. If required, the main landing gear lower structural support
shall be removed in accordance with the applicable technical manuals listed in Table 1-1.
4.28.3.3
Access. Not applicable.
4.28.3.4
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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