Cessna T303 Installation, Service & Parts Manual page 284

Avionic Installations Service/Parts Manual
provide the desired cable tension, reinstall safety
wire (34) on barrel (25).
Step 6. To replace the chain, or actuator
motor, the following procedures must be followed.
a. Remove the safety wire (34) securing the
turnbuckle barrel (35) and then remove the barrel
(35) from the fork (26) and LH terminal (37) by un-
screwing the barrel (35).
b. Remove the connecting link (6) which con-
nects the cable assembly (5) and chain (7).
c. Disconnect the electrical connector from the
actuator motor (19).
d. Remove the four screws and washers secur-
ing the actuator motor (19) to the actuator mount
(10), and then remove the actuator motor (19) and
chain (7 & 27).
e. Remove the safety wire securing the chain
guard posts and then remove the chain guard posts.
CAUTION
When the chain guard posts are being un-
screwed for removal, use caution to not
loose the locking washers.
f. To reinstall a new chain or actuator motor,
reverse these procedures and conduct a system
checkout as outlined in step 4 and check cable ten-
sion as outlined in step 5.
CAUTION
After the actuator is installed, lubricate
the sprocket (8), drive chain (7 & 27) and
gear teeth with a small amount of Aero-
shell No. 7 grease, or equivalent
Step 7.
Reinstall cover assembly (13A) with
three screws (13B) and two actuator bolts that were
removed in step 4.
Step 8. Unclamp rudder pedals that were
clamped in neutral position in step 1.
Step 9. Reinstall tail light wires that were re-
moved in step 3 and then reinstall stinger that was
removed in step 2.
POSTINSTALLATION CHECK.
No postinstallation adjustments of the yaw damper
are required, but a ground-operational check of the
equipment is recommended to verify that the equip-
ment is properly installed. Proceed as follows:
Step 1. Manually position aircraft rudder for
straight-and-level flight attitude.
Step 2. Close gyro (TURN/BANK) and yaw dam-
per circuit breakers (A/P CO & A/P ACT) and turn
on avionics power switches and aircraft master
switch. GYRO flag should disappear.
Step 3. Engage yaw damper switch; Y/D flag
should disappear.
Step 4. Depress disengage switch on control
wheel. The yaw damper switch should disengage
and the Y/D flag should reappear.
Step 5. Open gyro circuit breaker (TURN/
BANK); GYRO flag should reappear.
Step 6. Leaving connector and interconnecting
wiring attached to gyro-computer (Type G-840A),
remove screws that secure G-840A to instrument
panel.
Step 7. Hand-hold G-840A in normal mounting
position and close gyro circuit breaker (TURN &
BANK). GYRO flag should disappear.
Step 8. Check that rudder is still "streamlined",
then rotate G-840A for right yaw. The rate-of-turn
indicator on G-840A should deflect to the right.
Step 9. Rotate G-840A for left yaw. The rate-
of-turn indicator should deflect to the left.
Step 10. Engage yaw damper switch; the Y/D
flag should disappear.
Step 11. Swiftly rotate the G-840A for right yaw.
The rudder pedal should deflect for left rudder.
Step 12. Swiftly rotate the G-840A for left yaw.
The rudder pedal should deflect for right rudder.
Step 13. Disengage yaw damper switch and open
gyro and yaw damper circuit breakers (TURN &
BANK, A/P CO and A/P ACT).
Step 14. Turn off avionics power switches and
aircraft master switch.
CAUTION
To avoid overheating the actuator motor
during ground testing, do not leave the
yaw damper on for more than 10 minutes
continuously. Should the motor begin to
overheat, the thermostatic switch in the
motor assembly will turn the actuator off
for approximately ten minutes, and then
automatically reset.
Step 15. Reinstall G-840A in instrument panel.
Figure 7-2. Rigging Procedures For Cessna Yaw Damper - Type YD-840A (Sheet 2 of 4)
7-17