TM 1-1520-253-23
4.22.3.8 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.
4.22.4 Backup Method. None required.
4.22.5 System Securing. Clean the center cargo hook thoroughly to remove all residual magnetic particle media. Refer
to Post Cleaning and Restoration of Part or Area After NDI, paragraph 1.4.16. If removed, installation of cargo hook is
required in accordance with the applicable technical manual listed in Table 1-1. Secure the rescue hatch door.
4.23.1 Description (Figure 4-1. Index No. 23). The aft pylon equipment support structures consist of the aft trunnion
actuator forward and aft supports, aft swiveling actuator support, and aft bellcrank left and right support.
4.23.2 Defects. Defects may occur anywhere in the support structure. Inspect all reworked lugs for cracks. Particular
attention shall be given to radii at base of lugs and also to the lug bore surfaces and surrounding areas.
4.23.3
Primary Method. Eddy Current.
a.
Eddy Current Inspection Unit
b.
Probe, straight, shielded surface, 100 KHz-500 KHz
c
Probe, right angle, shielded surface, 100 KHz-500 KHz, 901/2 inch drop
d.
Cable Assembly
e.
Reference Block, three-notched aluminum (0.008, 0.020, and 0.040 EDM notches)
f.
Teflon Tape, refer to Table 1-8
g.
Aircraft Marking Pencil, refer to Table 1-8
