TASK 3 - BALANCE MAIN ROTOR - INITIAL
PROCEDURE 1: PREPARATION
Perform task 2, Flat Track Main Rotor on the Ground.
PROCEDURE 2: PERFORM INITIAL MEASUREMENT
a. Use cursor keys to highlight Aircraft Type, then press DO.
b. Use cursor keys to highlight aircraft type based on table 2, then press DO.
c. Tail Number is highlighted. Press DO.
d. Use cursor keys to highlight a tail number used in task 2, then press DO.
e. Flight Plan is highlighted. Press DO.
f. Use cursor keys to highlight INITIAL. Press DO.
g. Enter the Measure mode by pressing F1. Verify that Test State IDLE is highlighted.
h. Press DO when the aircraft is stable at the highlighted selection. Re-verify that the aircraft is at the required
Test State (IDLE, FPG100, or Hover) and press DO again. Perform this operation each time a measurement is
completed and another Test State is highlighted. The AVA will acquire track and vibration data at each Test
State and then return to the selection menu.
i. After the last measurement is completed, press DO on Finish, then press DO on Diagnostics. If measurements
are within specified limits, press QUIT to Main Menu and perform task 4, Track Main Rotor In Flight.
j. If measured values exceed specifications, press DO to calculate a solution. Evaluate the improvements
obtainable through recommended corrections. Perform all corrections as shown, ensuring that you display all
screens of a multiple screen solution.
k. Do not use a partial set of adjustments. If changes to the recommended corrections are desired, use the Edit
Adjustables and Edit Defaults options. The AVA will calculate a new set of corrections, use view predictions to
compare the new set of adjustments to the default solution to ensure the vibration is being reduced. Use all of
the new corrections.
l. After corrections are installed, take the measurements again to verify improvements.
m. After more than one measurement has been taken, trend flights to verify if the hover lateral vibration is being
PROCEDURE 3: PITCH LINK ADJUSTMENTS
When adjusting the pitch link on the AH-1SS, turn as
shown in figure 8 and count flats/turn at the specified
a. Turn barrel the specified amount displayed on the CADU.
b. Verify corrections by completing another ground run at 100% Nr, flat pitch.
c. Make appropriate logbook entry on the pitch control links and balance weighs that were changed, if any.
Figure 8. Pitch Link