TM 55-1520-240-T
2-1.3 VIBRATION FREQUENCY IDENTIFIED AS 225 RPM (1/REV) (Continued)
2-1.31
USE “0” MARKS PITCH LINK
ADJUSTMENT AS INPUT TO
PITCH LINK-LATERAL PRO-
GRAM.
USING THE PITCH LINK-LATERAL PROGRAM, DETERMINE VIBREX TIP
WEIGHT CORRECTION TO COMPENSATE FOR ANY PITCH LINK ADJUST-
MENT AND THE RECORDED LATERAL IMBALANCE AT 130 KNOTS. ADJUST
VIBREX TIP WEIGHTS (TM 55-1520-240-23). HAVE PILOT ESTABLISH 130
KNOT CRUISE PROFILE RECORD BLADE TRACK AND MEASURE VIBRATION.
ARE VERTICAL AND LATERAL VIBRATIONS WITHIN RANGE OF TABLE 2-
1.3?
ARE RECORDED VERTICAL Vl-
BRATION LEVELS WITHIN
RANGE OF TABLE 2-1.3?
ADJUST VIBREX BLADE TIP
WEIGHTS (TM 55-1520-240-23)
TO CORRECT LATERAL VIBRA-
TION, USING LATEST 130
KNOT VIB INPUT DATA IN PC
PITCH LINK-LATERAL PRO-
GRAM. MAKE NECESSARY AD-
JUSTMENTS AND PERFORM
THIS TASK AGAIN BEGINNING
AT 130 KNOT CRUISE.
LAND HELlCOPTER AND SHUT
DOWN ENGINES. OBSERVE RE-
CORDED BLADE TRACK AT 130
KNOTS. DID ANY BLADE CLIMB
OR DIVE?
CHECK TRIM TAB SETTING ON
CLIMBING OR DIVING BLADE
(TM 55-1520-240-23). IF TRIM
TAB IS SET CORRECTLY AS
STENCILED, REPLACE BLADE. IF
TRIM TAB SETTING IS lNCOR-
RECT, RESET TRIM TAB WITH
TAB BENDING TOOL AND PER-
FORM THIS TASK AGAIN BE-
GINNING AT 130 KNOT CRUISE.
1/REV VIBRATION LEVELS ARE
SATISFACTORY.
INSPECT ROTOR HEAD ASSY.
REF TM 55-1520-240-23.
TABLE 2-1.3. NORMAL ONE/REV VIBRATION LEVELS
FWD AND AFT ROTOR A T 225 RPM
FLIGHT PROFILE
ACCELEROMETER
LOCATION
HOVER
130 KT
155 KT
FWD VERTICAL
0 TO 0.2
0.2 TO 0.4
0.2 TO 0.6
FWD LATERAL
0.1 TO 0.3
0.2 TO 0.4
0.3 TO 0.5
AFT VERTICAL
0 TO 0.2
0.2 TO 0 4
0.2 TO 0.6
AFT LATERAL
0.1 TO 0.3
0.2 TO 0.4
0.3 TO 0.5
END OF TASK
Change 5 2-7
