TM 1-1520-238-T-4 Change 9 5–45 5–21. FLIGHT CHECK AND ADJUSTMENT USING AVA EQUIPMENT 5–21 Tools: Nomenclature Part Number Tool Kit, Aircraft SC518099CLA01 Mechanic’s Aviation Vibration 6625-01-282-3746 Analysis Test Set Helicopter Rotor Head 4920-01-180-7610 Balance and Blade Track Run Test Equipment Adapter, Socket A–A–2172 Wrench, 3/8, 1/2 Drive Crowfoot Attachment, FC42 1–5/16, 3/8 Drive Wrench, Open–end A–A–1356 1–1/4 & 1–5/16 (2) Wrench, Torque, TCI–1600 1/2 Drive Materials/Parts: Lockwire, MS20995NC32 Balance weights (as required) Personnel Required: 152FG Maintenance Test Pilot 152FG Pilot 67R Attack Helicopter Repairer 67R3T Inspector References: TM 1-1520-238-23 TM 1-1520-238-MTF Equipment Conditions: Ref Condition TM 1-1520-238-23 Helicopter safed Main rotor assembly inspection completed AVA rotor track and balance kit installed NOTE Main rotor in-flight vertical tracking should be performed when any of the following occurs: One per/rev in-flight vertical vibration is unacceptable. Changes have been made to the track of one or more main rotor blades as a result of performing ground tracking or initial adjustment. One or more blades have been changed. As per maintenance manual. a. PREPARATION NOTE Aircraft ground track and initial balance are to be completed prior to performing in-flight test states, unless a tune up of the in-flight vibration levels are desired. (1) Turn DAU ON. (2) Turn CADU ON. b. PERFORM FLIGHT MEASUREMENT (1) Press QUIT on the CADU until all selections are undefined.