6.5.5 System Securing. The bellcrank, if removed, requires installation in accordance with the applicable technical
6.6 FIRST STAGE CONTROL BELLCRANKS AND SUPPORTS (ET).
6.6.1 Description (Figure 6-1, Index No. 6). The first and second stage controls consist of bellcranks and linkage which
mix inputs from the thrust, pitch, roll, and yaw closet control motions into two motions which are transmitted directly to
the forward and aft controls.
6.6.2 Defects. Inspect for damage after removal of bent or sheared pin. Pay particular attention to rigging pin holes and
lug areas. No cracks are allowed.
6.6.3 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)
g. Aircraft Marking Pencil, refer to Table 1-8
220.127.116.11 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 bellcrank shall be removed in accordance with the applicable
18.104.22.168 Access. Access is through the flight controls closet to inspect the supports. See Figure 1-4 CH-47: 47; MH-47:
22.214.171.124 Preparation of Part. The bellcranks and supports shall be thoroughly cleaned. Refer to Preparation of Part or
126.96.36.199 NDI Equipment Settings.
a. Make the following initial settings on the Eddy Current Inspection Unit, NORTEC-19e .
- 200 KHz