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