TM 1-1520-264-23
4.29.4
Backup Method. None required.
4.29.5
System Securing. Clean the main landing gear jack pad adapter 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 jack pad, if removed, requires installation in accordance with the applicable technical manuals listed in Table 1-1.
4.30 MAIN LANDING GEAR TRAILING ARM CROSS TUBE (MT).
4.30.1
Description (Figure 4-1. Index No. 30)
. The main landing gear trailing arm cross tube is the location at which
the upper end of the trailing arm is attached to the helicopter fuselage.
4.30.2
Defects. This inspection is used to verify crack indications found visually on the main landing gear trailing
arm cross tube. No cracks are allowed.
4.30.3
Primary Method. Magnetic Particle.
4.30.3.1
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 t
o 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.
4.30.3.2
Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance and the main
landing gear trailing arm removed 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. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area
for NDI,
paragraph 1.4.4.
4.30.3.5
NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.
4.30.3.6
Inspection Procedure. A magnetic field shall be applied to the part perpendicular to the orientation of possible
cracks. Positions required for this inspection are illustrated in Figure 4-30.
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