TAIL ROTOR SWASHPLATE CONTROL BELLCRANK (MT).
Description (Figure 6-1. Index No. 40). The tail rotor swashplate control bellcrank is found just inboard of the
tail rotor swashplate. It connects the directional servocylinder to the swashplate.
Defects. This inspection is used to verify crack indications found visually on the tail rotor swashplate control
bellcrank. No cracks are allowed.
Primary Method. Magnetic Particle.
NDI Equipment and Materials. (Refer to Appendix B.)
Magnetic Particle Inspection Probe/yoke
Fluorescent Magnetic Particles, refer to Table 1-8
Consumable Materials, refer to Table 1-8
Aircraft Marking Pencil, refer to Table 1-8
Hand-held magnetic coil may be used. Refer to paragraph 220.127.116.11.2 and Figure 1-6.
Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance. A 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 tail rotor swashplate control bellcrank removed in accordance with
the applicable technical manuals listed in Table 1-1.
Access. Not applicable.
Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.
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 6-40.
Select AC on the AC/DC power switch.
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
Inspect for cracks using the black light.
Demagnetize before moving to the next position. Refer to paragraph 18.104.22.168.
Repeat steps a. through e. for positions 2 and 3.
Marking and Recording of Inspection Results. Mark and record the inspection results as required by