Cessna T303 Installation, Service & Parts Manual page 281

Avionic Installations Service/Parts Manual
c.
With the autopilot engaged, apply a "NOSE-
DOWN" pitch command via the PITCH wheel. suffi-
cient to cause the trim to run.
d. Adjust R46 (counterclockwise - slows trim)
on computer module A6 to obtain a rotation of the
aircraft's ELEVATOR TRIM wheel of one rotation
in 22 ± 2 seconds in the "NOSE-DOWN" direction and
one rotation in 22 ± 2 seconds in the "NOSE-UP"
position.
NOTE
With the autopilot disengaged the electric
trim actuator operates on a bus voltage
of 28. 8 volts dc in both the "NOSE-UP",
and "NOSE-DOWN" directions. The
average time for the ELEVATOR TRIM
command wheel to make three complete
rotations is 31. 5 ± 3 seconds. Check
system friction and voltage if time limit
is exceeded.
Step 17. Turn AP/ON autopilot (ON-OFF) switch,
avionics power switches, and aircraft master switch
to the OFF positions.
Step 18. Replace the access plates removed in
Steps 2 and 3, remove the external power source if
installed in Step 11 and remove the outside vacuum
source if installed in Step 12 or reset the GYRO
switch to the IN position.
Electric Trim Tab Simulated Air Load Test.
To per
perform a simulated trim tab air load test, refer to
Illustration H below and proceed as follows:
NOTE
The manual elevator trim control system
must be properly rigged, the aircraft elec-
trical operating voltage (28. 8 volts dc)
must be normal, the electric trim actuator
clutch must be properly adjusted and the
elevator must be secured in neutral posi-
tion, by using a control column neutral
rigging tool. Refer to the Control Column
Neutral Rigging Tool figure in the Elevator
Rigging Section for fabrication and installa-
tion of rigging tool, prior to completing the
following steps.
Step 1. Attach two angles (2 and 3) approxi-
mately 18 inches in length to the trailing edge of the
trim tab with a clamp (1) as illustrated to prevent
bending of tab trailing edge.
Step 2. Attach a cable (4) directly aft of the
trim tab horn assembly.
Step 3.
Attach 14 pounds minimum weight (in-
cluding the angles, clamps and cable) to the cable
and operate the trim switch to place the tab in the UP
position. The clutch MUST lift 14 pounds weight to
TRIM TAB
2
3
HORN AS
1. Clamp
2. Angle
3. Angle
Total test weight (including angles, clamps, cable and weight)
4.
cable
to be 14 or 22 Ibs depending on test to be performed.
Illustration H. Trim Tab Simulated Air Load Test
Figure 7-1.
Rigging Procedures for Cessna 400B and 400B IFCS (Types AF-550A & IF-550A) (Sheet 13 of 14)
7-14