Track and balance of main rotor blades should be performed when any of the following occurs:
One or more blades have been changed.
One or more tip caps have been changed.
One or more pitch control rods or rod end bearings have been changed.
The main rotor blades have been removed and the hub has been disassembled.
As per applicable maintenance manuals.
A typical track and balance mission from start to finish includes the following:
Phase main rotor blades as per applicable maintenance manual. For AH-64A refer to TM 1-1520-238-23, or
for AH-64D refer to the Longbow IETM, TM 1-1520-LONGBOW/APACHE.
Phasing the main rotor blades is an important starting
point for track and balance and if not performed
correctly, will not allow track and balance to be
completed in a timely manner.
Install the Aviation Vibration Analyzer, refer to task 1 of this document.
Perform preparation for main rotor track and balance, task1 procedure 2.
Tail rotor balance will be accomplished prior to in-flight
track and balance. The tail rotor balance procedure is
performed during ground run operations. If the tail rotor
is wired, take the measurements during the same
ground runs used for main rotor ground track and
If it is anticipated that the rotor track and balance has not
been disturbed (i.e., track and balance is being
performed to verify that nothing has changed), and if
ground track is within 1.5 inch high to low blade and
ground balance is 0.2 ips or less, proceed directly to
flight. If flight measurements are significantly above
limits, perform GROUND test plan. If flight states require
only fine-tuning adjustments, skip GROUND test plan.
Perform tail rotor balancing if required, task 4.
Perform GROUND track and balance, task 2.
Perform FLIGHT track and balance, task 3.
The AH-64 Flight Plans are listed below with a brief description of their purpose. Table 1 (AH-64A) and table 2 (AH-
64D) show the Test States that comprise each Flight Plan. The selectable Flight Plans are listed in order of
appearance in the menu on the CADU and not in the order in which they are to be performed. The AH64NB_R.CMD
(AH-64A) and AH64D2_R.CMD (AH-64D) script files are used when the Signal Processing Unit (SPU) and
permanently installed vibration detection system is by-passed.