18.104.22.168 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, components shall be removed in accordance with the applicable
22.214.171.124 Access. Access is through the cabin crown tunnel covers. See Figure 1-4- CH-47: 8; MH-47: 3.
126.96.36.199 Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or
188.8.131.52 NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.
184.108.40.206 Inspection Procedure. A magnetic field shall be applied to the part perpendicular to the
orientation of possible cracks. Positions for this inspection are illustrated in Figure 3-3.
a. Select AC on the AC/DC power switch.
b. Place probe/yoke on part in Position 1 as shown.
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
d. Inspect for cracks using the black light.
Rotate the adapter and place either probe leg on the third adapter ear.
g. Repeat steps a. through e. for Position 2.
220.127.116.11 Marking and Recording of Inspection Results. Mark and record the inspection results as
18.104.22.168 Demagnetization. With the switch remaining
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.
3.3.4 Backup Method. None required.
3.3.5 System Securing. Clean the driveshaft 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. If removed, install the adapters in
accordance with the applicable technical manuals listed in Table 1-1. Secure the cabin crown tunnel covers.
3.4 FORWARD DRIVESHAFTING TUBES (ET).
3.4.1 Description (Figure 3-1, Index No. 4). The forward driveshafting transmits torque from the combining transmission
to the forward transmission. It consists of seven shafts coupled by six adapter / assemblies. The shafts are numbered 1
through 7 beginning with the forward shaft.
3.4.2 Defects. Defects may occur anywhere on the surface of the tubes. All dents, scratches, nicks, or gouges shall be
inspected to ensure they do not conceal cracks. No cracks are allowed.