TASK 1 TEST EQUIPMENT INSTALLATION/CHECKOUT
It is strongly recommended that the AVA diagnostic
solutions for the main rotor be made, using the externally
mounted accelerometers, along with AH64NB/AH64D2
script files. Errors due to faulty on-board accelerometers,
faulty SPUs, and/or poor SPU/AVA interface can make the
track and balance exercise ineffective.
For main rotor track and balance, if the external wiring of
accelerometers method has been used, (task 1 procedure 3)
ensure that the lateral accelerometer at the pilot station and
the vertical accelerometer at the CPG station have been
properly oriented. Improper orientation will cause the CADU
to suggest improper adjustments. The lateral accelerometer
should be oriented identically to the on-board lateral
accelerometer, with the connector and cable pointing to the
pilots right. The vertical accelerometer should be oriented
identically to the on-board one with the connector pointing
down. See figures 3 and 4. Also ensure that the lateral
accelerometer in the pilot station has been connected to
DAU receptacle ACC1 and the vertical accelerometer has
been connected to ACC2. Improper connection of
accelerometers will cause the CADU to suggest improper
adjustments causing the rotor to become rougher.
a. Remove AVA blade tracking equipment from transport case. Check for possible damaged equipment and
b. Install DAU in the canvas carrying case.
c. On AH-64D helicopters remove soundproofing that covers the interior opening of the fuselage through hole
located to the left of the CPG seat.
d. On AH-64D helicopters remove the 5L90 cover plate located on the outside of the aircraft below the CPG
window and aft of the UTD mounting point.
e. Route the UTD cable (29325701) through fuselage hole. Connect the UTD cable (29325701) to DAU
connector labeled TRACKER 1.
Place DAU on the left outboard side of the copilot's armor plate oriented such that the on/off switch is forward,
with connectors facing up and secure DAU using canvas straps and D-rings. See figure 2.
In order to prevent possible false indications on the AH-64
tail rotor gearbox indicator, the AVA AH-64 umbilical cable
part number 29304600 should be modified. Perform a
continuity check on the connections between pins 17, 28 and
12 on P1 to pins K, L and C on P4, respectively. If there is
continuity, the cable must be modified using the following
procedure: remove two screws from connector P4
(MS3116J14) backshell clamp. Unscrew backshell and pull
back backshell and sleeve to expose wire connections.
Desolder the wires from pins C, K and L and apply heat
shrink tubing to wire ends. Replace sleeve, backshell and
clamp. With a permanent marker, strike out the revision
letter located on the cable ID tag immediately after the part
number. Mark tag with the letter D. Cable ID tag should
read: 29304600 D.