TM 1-6625-724-13&P
0069 00
0069 00-31
Install vibration equipment (task 1)
(pilot, copilot and pilot heel vertical accelerometers)
Perform FLIGHT Measurement (task 4) to obtain
Pilot Heel Vertical at 120 knots, 100%Nr
Pilot Heel Vertical at 140 knots, 100%Nr
Cockpit A+B at 140 knots, 100%Nr
Perform BOXABS Measurement:
140 knots Cabin Absorber Frame Vertical at
98, 99, 100, 100.5, 101, and 102%Nr
Install vibration equipment for task 7
(Cabin Absorber Frame Vertical accelerometer)
Add Tuning Weight to Nose Absorber
based on maximum PHV ips level
(See table 2.2)
Remove Tuning Weight from Nose
Absorber based on Minimum
PHV ips level (See table 2.3).
Adjust Cabin Absorber Tuning Weight
based on minimum Cabin Absorber
frame ips level (See table 2.1).
(REFLY)
(REFLY)
Is Main Rotor 4/REV Cockpit Vibration within the following limits?
Cockpit A+B 0.40 ips or less at 140 knots, 100%Nr
Pilot Heel Vertical 0.60 ips or less at 120 knots and 140 knots, 100%Nr
Main Rotor 4/REV
Vibration is Acceptable
Is Cockpit Vertical at 140 knots
0.40 ips or less?
Is Pilot Heel Vertical 0.60 ips or less
at 120 knots and 140 knots, 100 %Nr?
Is Pilot Heel Vertical 0.30 ips or less
at 120 knots and 140 knots, 100 %Nr?
Is 140 knots Cabin Absorber Frame
Vertical minimized at 100.5%Nr?
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
Install vibration equipment task 1
(pilot, copilot and pilot heel accelerometers)
Perform FLIGHT Measurement (task 4)
Pilot Heel Vertical at 120 knots, 100%Nr
Pilot Heel Vertical at 140 knots, 100%Nr
Cockpit A+B at 140 knots, 100%Nr
(REFLY)
Figure 18. UH-60 Box Frame Absorber Main Rotor 4/REV Vibration Check And Tuning Procedure
