TM 1-1520-238-MTF
4-17
Change 5
b. Main rotor reflex tab adjustments
approximate one inch tip travel per one
degree change. Use the appropriate tab
pocket(s) to correct track variances when tip
path relationships change more than 2
inches between flat pitch and hover tracks. If
track variance is less than 2 inches, use
pitch links to correct hover track. A
combination of reflex tab and pitch link
adjustments is used to correct track changes
at all other airspeeds.
c. Adjust blade weights (main and/or tail rotor)
per values determined from Vibrex chart.
d. Adjust blade phase only if tracking indicates
phase change or per Vibrex chart.
e. Apply rotor smoothing procedure as
necessary to attain least possible vibration
level. A value of 0.3 IPS in either vertical or
lateral vibrations straight and level should be
considered the maximum acceptable level
not requiring correction. A value of 0.76 IPS
should be considered the maximum
acceptable level during turning flight.
f. Upon attaining acceptable levels of vibration,
record peak values and clock angles, tab
pocket settings, and scan for peak IPS
values through range of Vibrex monitor.
Retain this record for use in troubleshooting
vibrations as necessary.
2. Tail Rotor Balance Check.
Refer to
TM 1-1520-238-T-4.
3. Main Rotor Track and Balance.
Refer to
TM 1-1520-238-T-4.
