Van's Aircraft RV 12iS, Maintenance Manual

Page: 107 / 222

Rev: 2 Date: 11/15/18
8-7
P
ITCH
-
TRIM SERVO REPLACEMENT
Special Tools D-sub pin extractor
Expendable None
Replaceable Pitch-Trim servo
Service Rating Line
Minimum Certification LSA-RM, or A&P
Additional References KAI Section 11
R
EMOVAL
1. Disconnect the negative (-) battery cable.
2. Remove the upper and lower tailcone fairing. (3-4)
3. Disconnect the pitch-trim servo D-sub connector. Detach the servo connector
half from the servo tray.
4. Disconnect the trim servo from the AST assembly by removing the bolt, washers
(3) and nut.
5. Remove the trim servo from the servo tray by removing the screws (4), washers
(4), and nuts (4).
6. Remove the 5 wires from the d-sub connector using a pin extractor.
7. Take note of the position of the clevis and jam nut on the servo shaft and then
remove them from the servo.
I
NSTALLATION
1. Thread the jam nut onto the new pitch-trim servo shaft until it contacts the pitch
trim servo shaft housing. Thread the pitch-trim servo shaft onto the clevis rod end
on the pushrod assembly until it contacts the jam nut. Back the pitch-trim servo
off two full turns. Tighten the jam nut against the pushrod assembly.
2. Insert the wire pins on the new servo into the appropriate pin locations on the d-
sub connector (Refer to KAI Section 11).
3. Install the servo on the servo tray by reversing the process used for removal.
4. Switch on the master switch and verify that when the pitch trim is activated in the
nose down direction, the antiservo tab assembly moves up. If the AST moves in
the wrong direction, double check that the servo wires were inserted into the
correct connector pin locations.
5. Confirm proper movement of the pitch trim indicator. If incorrect, double check
the wiring on the connector.