TM 1-1520-253-23
LANDING GEAR AXLE (MT).
4.16.1 Description (Figure 4-1. Index No. 16). The landing gear axle is a steel tube which supports the wheels in the
landing gear assembly. This inspection is applicable to both inboard and outboard as well as forward and aft axles.
4.16.2 Defects. Defects may occur anywhere on the surface of the landing gear axle. No cracks or bends are allowed.
4.16.3 Primary Method. Magnetic Particle.
4.16.3.1
NDI Equipment and Materials. (Refer to Appendix B.)
a.
Magnetic Particle Inspection Probe/Yoke
b.
Magnetometer
c.
Black Light
d.
Fluorescent Magnetic Particles
e.
Consumable Materials, refer to Table 1-8
f.
Aircraft Marking Pencil, refer to Table 1-8
NOTE
Hand-held coil may be used. Refer to paragraph 1.4.8.1.2 and Figure 1-6.
4.16.3.2
Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance. 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 landing gear axle shall be removed in accordance with
the applicable technical manuals listed in Table 1-1.
4.16.3.3
Access. Not applicable.
4.16.3.4
Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
4.16.3.5
NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.
4.16.3.6
Inspection Procedure. A magnetic field shall be applied to the part perpendicular to the orientation of
possible cracks. Position required for this inspection is illustrated in Figure 4-16.
a.
Select AC on the AC/DC power switch.
b.
Place probe/yoke on part at position 1 as shown.
c.
Press the test switch and apply a light coat of magnetic particle media at the same time. Remove the
media momentarily before removing the current. Current should be applied for . no more than five
seconds.
d.
Inspect for cracks using the black light.
