TM 1-6625-724-13&P
0069 00
0069 00-5
Vibration Test Sequence
This section explains the sequence in which the vibration tasks within TM 1-6625-724-13&P must be carried out.
Each block in figure 1 represents a separate vibration task. The tasks are classified as either Ground Run tasks or
Flight Test tasks. All Ground Run tasks must be completed before the Flight Test tasks can be started.
The ground run vibration tasks shown on the top row of figure 1 can be accomplished interchangeably. However,
main rotor flat pitch tracking must be completed before the main rotor ground balance is done.
The flight test vibration tasks can be accomplished once the ground run tasks have been completed.
If aircraft component disassembly or replacement occurs after a vibration task has been initially completed, the
vibration tasks that are affected by the component disassembly or replacement must be re-done individually.
GROUND
RUN
FLIGHT
TEST
MAIN ROTOR
ROLL/VERTICAL IN FLIGHT
(TASK 4)
Required Test Conditions:
Flat Pitch / 100% Nr
Hover / 100%Nr
80 knots / 100% Nr
120 knots / 100% Nr
145 knots / 100% Nr
TAIL ROTOR
BALANCE
(TASK 6)
Required
Test Condition:
Flat Pitch / 100%Nr
ENGINE
OUTPUT SHAFT
BALANCE
(TASK 9)
Required
Test Condition:
Flat Pitch / 100%Nr
MAIN ROTOR
GROUND
TRACKING
(TASK 2)
Required
Test Condition:
Flat Pitch / 100%Nr
MAIN ROTOR
GROUND
BALANCE
(TASK 3)
Required
Test Condition:
Flat Pitch / 100%Nr
(TASK 8)
Required
Test Condition:
Flat Pitch / 100%Nr
ENGINE
OUTPUT SHAFT
&
OIL COOLER
VIBE CHECK
IF
REQUIRED
MAIN ROTOR
4/REV VIBRATION
ABSORBER TUNING
(TASK 7)
Required Test Conditions:
145 knots / 96% Nr
145 knots / 97% Nr
145 knots / 98% Nr
145 knots / 99% Nr
145 knots / 100%Nr
145 knots / 101%Nr
145 knots / 102%Nr
145 knots / 103%Nr
145 knots / 98% Nr
145 knots / 99% Nr
145 knots / 100%Nr
145 knots /100.5%Nr
145 knots / 101%Nr
145 knots / 102%Nr
ABTUNE OR BOXABS
MAIN ROTOR
GROUND
BALANCE
(TASK 5)
Required
Test Condition:
Flat Pitch / 100%Nr
POST FLIGHT
IF
REQUIRED
1) Ground Run Tasks must be completed before the Flight Test Tasks can be started.
2) Main Rotor Flat Pitch Track (Task 2) must be completed before Main Rotor Ground
Balance (Task 3) can be started.
3) Engine Output Shaft Balance (Task 9) is only required if Engine & Oil Cooler Vibe
Check (Task 8) is out of limits.
4) Post Flight Ground Balance (Task 5) is only required if FPG A-B is out of limits.
5) The aircraft absorber configuration will determine what absorber flight plan will
will be used.
TUNING
Figure 1. Vibration Test Sequence
