18-60 Tail Rotor Blade Rigging
1. Level helicopter laterally, and longitudinally via main rotor hub, per § 8-12.
2. Place left (or right) pedal against its stop. Position tail rotor blades parallel to the
tailcone.
3. Refer to Figure 18-11. Tape a tracking stick to tailcone at blade tip. A tracking stick
can be made using a 1” x 12” strip of aluminum with a 90º bend 2 inches from one end.
4. Rotate tail rotor shaft weldment and mark tracking stick where each blade tip drain hole
passes. Adjust (teeter) tail rotor hub on output shaft until both blade tips pass the same
point on the tracking stick.
5. Using felt tip marker, mark inboard surface of both tail rotor blades 7.25 inches from
each blade tip. Lay 1-inch wide strip of masking tape chordwise on each blade, centered
over marking. Mark each blade with a different color designation, such as red or blue.
6. Have a second person hold one blade tip at the left pedal track mark with the left pedal
against its stop. Position MT525-2 rigging fixture on the aft blade, against the inboard
surface. Position propeller protractor against the fixture, measure the blade angle, and
record data below. Rotate the tail rotor 180°, and record the opposite blade angle.
Pedals Full Left
Blue Blade °
Red Blade + °
= °
÷ 2 = ° (18.5/19.0° required)
7. Difference between blue and red blade angles may not exceed 0.4°. If blade angles
exceed this limit, remove tail rotor assembly per § 64-10, rotate assembly one-half
revolution, and install assembly per § 64-10. Repeat previous steps. If blade angles still
exceed relative limit, contact RHC Technical Support for replacement blade assistance.
8. Adjust C121-17 push-pull tube rod ends per § 5-33 and Figures 5-1 & 5-2 as required to
obtain blade angle between 18.5° and 19.0°. One full turn of the rod end will change
the blade angle 0.33°.
9. Have a second person hold one blade tip at the right pedal track park with the right pedal
against its stop. Position MT525-2 rigging fixture on the aft blade, against the inboard
surface. Position propeller protractor against the fixture, measure the blade angle, and
record data below. Rotate the tail rotor 180°, and record the opposite blade angle.
Pedals Full Right
Blue Blade °
Red Blade + °
= °
÷ 2 = ° (15.5/16.5° required)
10. Adjust C121-17 push-pull tube rod ends per § 5-33 and Figures 5-1 & 5-2 as required
to obtain blade angle between 15.5° and 16.5°. If adjusted, recheck left pedal blade
angles per previous steps.
MAY 2015 Chapter 18 Track and Balance Page 18.29
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