Flight Controls; Elevator System - Cirrus DESIGN SR20 Pilot's Operating Handbook And Flight Manual

Section 7 Cirrus Design
Airplane and Systems Description SR20

Flight Controls

The aircraft uses conventional flight controls for ailerons, elevator and
rudder. The control surfaces are pilot controlled through either of two
single-handed side control yokes mounted beneath the instrument
panel. The location and design of the control yokes allow easy, natural
use by the pilot. The control system uses a combination of push rods,
cables and bell cranks for control of the surfaces.

Elevator System

The two-piece elevator provides airplane pitch control. The elevator is
of conventional design with skin, spar and ribs manufactured of
aluminum. Each elevator half is attached to the horizontal stabilizer at
two hinge points and to the fuselage tailcone at the elevator control
sector. Elevator motion is generated through the pilot's control yokes
by sliding the yoke tubes forward or aft in a bearing carriage. A push-
pull linkage is connected to a cable sector mounted on a torque tube.
A single cable system runs from the forward elevator sector under the
cabin floor to the aft elevator sector pulley. A push-pull tube connected
to the aft elevator sector pulley transmits motion to the elevator
bellcrank attached to the elevators.
Pitch Trim System
Pitch trim is provided by adjusting the neutral position of the
compression spring cartridge in the elevator control system by means
of an electric motor. It is possible to easily override full trim or autopilot
inputs by using normal control inputs. A ground adjustable trim tab is
installed on the elevator to provide small adjustments in neutral trim.
This tab is factory set and does not normally require adjustment. An
electric motor changes the neutral position of the spring cartridge
attached to the elevator control horn. A conical trim button located on
top of each control yoke controls the motor. Moving the switch forward
will initiate nose-down trim and moving the switch aft will initiate nose-
up trim. Neutral (takeoff) trim is indicated by the alignment of a
reference mark on the yoke tube with a tab attached to the instrument
panel bolster. The elevator trim also provides a secondary means of
aircraft pitch control in the event of a failure in the primary pitch control
system not involving a jammed elevator.
Elevator (pitch) trim operates on 28 VDC supplied through the 2-amp
PITCH TRIM circuit breaker on ESS BUS 2.
7-8 P/N 11934-004
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