TM 1-1520-265-23
5.6.3
Primary Method. Magnetic Particle.
5.6.3.1
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.
5.6.3.2
Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance and the engine
removed in accordance with the applicable technical manuals listed in Table 1-1.
5.6.3.3
Access. Not applicable.
5.6.3.4
Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
5.6.3.5
NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.
5.6.3.6
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 5-6.
a.
Select AC on the AC/DC power switch.
b.
Place probe/yoke on part in position 1 as shown for each fitting.
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.
e.
Demagnetize before moving to the next position. Refer to paragraph 5.6.3.8.
f.
Repeat steps a. through e. for position 2 on each fitting.
5.6.3.7
Marking and Recording of Inspection Results. Mark and record inspection results as required by
paragraph 1.3.
5.6.3.8
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.
5.6.4
Backup Method. Fluorescent Penetrant, refer to paragraph 1.4.7.
5.6.5
System Securing. Clean the fittings 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 engine requires installation in
accordance with the applicable technical manuals listed in Table 1-1.
5-11
