TASK 2 - TRACK AND BALANCE MAIN ROTOR ON GROUND
The purpose of main rotor adjustments made at flat pitch (full down collective) and 100% (101% for (AH-64D) Nr is to
establish a good starting point for forward flight track and balance and should normally be accomplished prior to
initiating FLIGHT track and balance. Flight Plan GROUND will provide both weight and pitch link corrections for this
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 inches between 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.
Tail rotor balance should be accomplished before any in-
flight checks are performed. The tail rotor balance
procedure can be performed during a main rotor ground
Ground Track and Balance Limits
The AVA will show the following limits for ground track and lateral vibration:
0.25 inch between high blade to low blade
It should be possible to achieve ground balance below
0.1 ips and it is encouraged to do so. Ground track
significantly below 0.25 inch is not justified.
PROCEDURE 1: PERFORM GROUND MEASUREMENT
a. Operate aircraft.
If vibration is too severe to bring rotor speed up to full
operating rpm, hold rotor speed steady at the highest
rotor speed that can be safely sustained for the first AVA
b. Power up DAU.
c. Wait approximately 10 seconds and power up CADU.
d. Press QUIT on CADU until the Main Menu appears.
e. Cursor up to highlight "Aircraft Type" and press DO. Cursor to highlight the appropriate aircraft type (AH64_R or
AH64D_R for on-board accelerometers or AH64NB_R or AH64D2_R for externally mounted accelerometers) and
On the Main Menu, cursor to highlight tail number and press DO. Select tail number from the list, or highlight
NEW and press DO to input a new tail number, (up to 7 digits) using the number keypad. When done, press DO.