TM 1-1520-264-23
5.3.3.3
Access. Remove engine.
5.3.3.4
Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
5.3.3.5
NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.
5.3.3.6
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 5-3.
a.
Select AC on the AC/DC power switch.
b.
Place probe/yoke on part in 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.
e.
Demagnetize before moving to the next position. Refer to paragraph 5.3.3.8.
f.
Repeat steps a. through e. for positions 2 and 3.
5.3.3.7
Marking and Recording of Inspection Results. Mark and record the inspection results as required by paragraph
1.3.
5.3.3.8
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.
5.3.4
Backup Method. None required.
5.3.5
System Securing. Clean the engine mount 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 mount requires installation in
accordance with the applicable technical manuals listed in Table 1-1.
5.4 FORWARD LOWER ENGINE MOUNT (MT).
5.4.1
Description (Figure 5-1. Index No. 4). The forward lower engine mount is attached to the lower forward
portion of the engine main frame. This task is applicable to mounts on both engines.
5.4.2
Defects. This inspection is used to verify crack indications found visually. No cracks are allowed.
5.4.3
Primary Method. Magnetic Particle.
5.4.3.1
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
5-6
