Extra 300/SC, Maintenance Manual

Page: 88 / 250

CHAPTER 27
PAGE 29
MAINTENANCE MANUAL EXTRA 300/SC
PAGE DATE: 12. February 2019
27-30-00 ELEVATOR AND TAB
Description and Operation
Refer to Figure 19. The control movements are transferred
from the control stick (1) to the elevator (9) by push-pull
rods (2), a rocker type bellcrank (3) and an actuator arm (4).
The bell crank has a sealed ball bearing. The elevator is
mounted at five points in spherical bearings pressed into
aluminium hinge arms. For lightning protection reason each
hinge arm is grounded to the corresponding attachment
bracket at the elevator by bonding leads. The travel stops are
located at the torque tube.
The mass balance weights (8) are mounted in an unshielded
horn balance of 175 mm span.
An access panel is located at the right side of the rear
fuselage.
The elevator trim control servo (5) is controlled by the trim
switch on the instrument panel. There also a scale is installed
showing the state of the trim system. Pitch trim is done by
means of the trim tab (7) on the right elevator trailing edge
operated by a bowden cable mechanism (6). The trim tab is
mounted by two piano hinges.
The trim tab is not mass balanced.
27-30-01 Elevator
Removal/Installation
Before the removal of the elevator, the vertical stabilizer has
to be disassembled.
1 Remove the respective access panels.
2 Remove the rudder per Chapter 27-20-01.
3 Remove the vertical stabilizer per Chapter 55-30-00.
4 Loosen the bowden cables from the trim tab. If a replace-
ment is necessary order new cable.
5 Disconnect the elevator actuator arm from the push-pull rod.