APR 2017 Chapter 18 Track and Balance Page 18.7B
18-13 Track Adjustment (continued)
A. Main Rotor Blade Pitch Link (continued)
2. For medium length adjustment, adjust upper rod end per the following:
a. Refer to Figure 18-3A or 18-3B. Using backup wrench on barrel assembly or
fitting, loosen upper rod end palnut and jam nut. Remove hardware securing
rod end to pitch horn.
b. Rotate upper rod end to shorten or lengthen pitch link as required. One-half
turn of upper rod end changes blade track approximately 0.25 inch. One-
half turn of upper rod end changes blade angle by approximately 0.24°.
c. Refer to Figure 5-1. Verify rod end threaded shank blocks passage of 0.020-
inch diameter lockwire through barrel asssembly (upper), or fitting, witness
hole. Install hardware securing rod end to pitch horn and standard torque
fasteners per § 20-32.
d. Position rod ends to allow as much pitch link rotation as possible without
binding. Using backup wrench on barrel assembly or fitting, standard torque
upper rod end jam nut and palnut per § 20-32.
e. Repeat steps on opposite pitch link as required; torque stripe per Figure 5-1.
3. For coarse length adjustment:
a. C258-5 Pitch Link: Adjust lower rod end per the following:
i. Refer to Figure 18-3A. Using backup wrench on barrel assembly, loosen
21FKF-813 nut at lower rod end. Remove hardware securing lower rod
end to swashplate.
ii. Rotate lower rod end to shorten or lengthen pitch link as required. One-
half turn of lower rod end changes blade angle by approximately 0.44°.
iii. Refer to Figure 5-1. Verify rod end threaded shank blocks passage of
0.020-inch diameter lockwire through barrel asssembly (lower) witness
hole. Install hardware securing rod end to swashplate and standard
torque fasteners per § 20-32.
iv. Position rod ends to allow as much pitch link rotation as possible
without binding. Using backup wrench on barrel assembly, special
torque 21FKF-813 nut per § 20-33.
v. Repeat steps on opposite pitch link as required; torque stripe per Figure 5-1.
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