TM 1-1520-238-T-4
Change 4
6–163
6–81.
DRIVE SYSTEM – VIBRATION MAINTENANCE OPERATIONAL CHECK (cont)
6–81
NR VERTICAL
SCALE
NP 2 VERTICAL
SCALE
NP 1 VERTICAL
SCALE
NR VERTICAL
SCALE
NP 2 VERTICAL
SCALE
NP 1 VERTICAL
SCALE
(ACV)
(ACW)
M58-288A
Figure 6–22.
Pilot ENG–RTR RPM% Indicator
Task
Result
c. On pilot and CPG master caution/warning
panels (fig. 6–18), check LOW RPM
ROTOR indicators. Listen for low rotor
audible warning in pilot and CPG headsets.
If pilot LOW RPM ROTOR indicator does not light at
93% or less, go to paragraph 6–83.
If CPG LOW RPM ROTOR indicator does not light at
93% or less, go to paragraph 6–84.
If low rotor audio warning is not heard in both
headsets, refer to TM 1-1520-238-T-6 to troubleshoot
low rotor audio warning.
Delaying decrease of PWR lever may result in an engine/rotor overspeed.
CAUTION
d. Set ENG 1 PWR lever to LOCKOUT. Note
Np/Nr/NG increase. Then immediately retard
ENG 1 PWR lever to a position midway
between FLY and IDLE.
