Cessna T303 Installation, Service & Parts Manual page 275

Avionic Installations Service/Parts Manual
3
A
1. Support
2. Neutral Rigging Tool
3. Instrument Panel
4. Pilot's Control Column
.46 inch
62 inch
Press fit
78"
.19"R. (Typ)-
.35"R. (Typ)
.30 inch
Detail A
Fabricate from .125 inch steel plate and .209 inch
dia. drill rod according to dimensions shown.
Illustration D. Control Column Neutral Position Rigging Tool
the instructions in the T303 Service Manual and then
again, recheck the autopilot rigging per the preceed-
ing instructions.
Step 13. Remove rigging tool securing the con-
trol wheels.
Step 14.
In order to eliminate the gyro roll and
pitch signals generated by a non-erected gyro, the
400B autopilot has a GYRO switch located on the rear
of the control head; set the GYRO switch to the OUT
position. Since the 400B IFCS does not have a gyro
out switch, it will be necessary to hook up an outside
vacuum source or operate one of the aircraft engines
to erect the gyro.
NOTES
If an outside vacuum source is used, it should
be calibrated in inches of mercury and the
desired suction range required to erect the
gyro is 4. 6 to 5. 4 inches of mercury.
If one of the aircraft's engines is operated to
erect the gyro, the engine should be run at
1000 RPM to provide the desired amount of
vacuum and maintain proper bus voltage.
Step 15. Turn ON aircraft master switch, L & R
avionics power switches, and autopilot (AP) switch
and allow pitch wheel to run to electrical neutral.
Step 16. Pull control wheel back until control
forces are neutralized. While still gripping the con-
trol wheel to prevent full travel, rotate the PITCH
command wheel in the "NOSE-DOWN" direction.
The control wheel should travel forward. Turn auto-
pilot AP switch OFF and then back ON again and al-
low PITCH command wheel to neutralize.
Pull con-
trol wheel back until there is a slight tendency for
the wheel to travel forward. Rotate the PITCH com-
mand wheel in the "NOSE-UP" direction. The con-
trol wheel should now be held from traveling forward
by actuator force. Push control wheel forward 2 to
3 inches to confirm that actuator force is being ap-
plied.
NOTES
Due to the ground loads applied to the eleva-
tors, elevator travel from stop to stop can-
not be obtained in most instances while con-
ducting ground tests. In view of this fact,
the service technician should use care in
observing the preceeding procedures in step
16 and not assume the elevator actuator is
not completely operational. Flight tests in
accordance with the appropriate 400B Ser-
vice/Parts manual should be conducted after
rigging procedures checkout to fully deter-
mine if the system is completely operation-
al. Be sure the Gyro switch pulled out in
step 12 is pushed back IN, prior to conduct-
ing flight tests.
Check that autopilot may be overpowered
using the control wheels at any time; how-
ever this practice should be kept to a min-
imum since slip-clutch wear will result
from extended periods of manual overpow-
er. Also extended periods of manual over-
powering the actuator will cause a thermo-
static switch to remove power from the ac-
tuator. After approximately 10 minutes,
the switch automatically resets to close
the autopilot interlock circuit Power can
then be reapplied to the actuator by re-en-
gaging the AP/ON-OFF switch.
Step 17. Turn OFF autopilot (AP) switch, avi-
onics power switches, and aircraft master switch.
Step 18. Replace the aft baggage partition re-
moved in step 3.
Figure 7-1.
Rigging Procedures for Cessna 400B and 400B IFCS (Types AF-550A & IF-550A) (Sheet 7 of 14)
7-8
1