TM 1-6625-724-13&P
0071 00
0071 00-21
TASK 3 - TRACK AND BALANCE MAIN ROTOR IN FLIGHT
Figure 9. Polar Chart
d. As the caption says in figure 9, if blade 2 was adjusted to bring the aircraft into track that would be a mistake
and would increase the vertical vibration (refer to the AH-64 coefficient polar chart for vertical vibration at the
end of this section).
e. This information in the displays should not be used to make corrections, this should be used to make changes
to the diagnostics to obtain a better solution. After all this information is reviewed, it is time to enter
Diagnostics.
WARNING
Total blade balance weight is not to exceed 1017
grams, nine -3 weights, on a single blade.
WARNING
Total blade trim tab bends are not to exceed +\- 5
degrees in any pocket. Tabs should be bent
uniformly at all locations suggested by the AVA
diagnostics.
NOTE
AVA moves are changes to the adjustable components
and, as such, are to be added or subtracted to whatever
the component is currently set to. For example, when
the AVA calls for 1 degree down in pockets 4-10, that 1
degree is to be made to any bend already existing in
those pockets.
NOTE
If any blade shows a 6-10 or 8-10 tab adjustment of 2
degrees or more, it is recommended to Edit Adjustables
to turn off the 2 degree or greater 6-10 or 8-10 tab
region and turn on the next larger tab region for that
blade, then recompute the adjustment. For example, if
the AVA solution calls for a 2 degree bend in pockets 6-
10 on Blade 1, use Edit Adjustables to turn off the Blade
1 6-10 tab and turn on Blade 1 4-10 tab and recompute
the adjustments.
This is the direction that the
vibration readings would move
if the tab or pitch link was
adjusted up on blade 2. All of
the vibration readings would
move away from the center of
the circle and get worse.
