Trim Systems; Pitch Trim Control System; Roll Trim Control System - Cirrus DESIGN SR20 Information Manual

Section 7 Cirrus Design
Airplane Description SR20

Trim Systems

Roll and pitch trim are provided by adjusting the neutral position of a
compression spring cartridge in each control system by means of an
electric motor. The electric roll trim is also used by the autopilot to
position the ailerons. It is possible to easily override full trim or
autopilot inputs by using normal control inputs.
Ground adjustable trim tabs are installed on the rudder, elevator and
right aileron to provide small adjustments in neutral trim. These tabs
are factory set and do not normally require adjustment.

Pitch Trim Control System

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. Pressing down on the switch will disconnect the autopilot if the
autopilot was engaged. 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
circuit breaker on Main Bus 1.

Roll Trim Control System

An electric motor changes the neutral position of a spring cartridge
attached to the left actuation pulley in the wing. A conical trim button
located on top of each control yoke controls the motor. Moving the
switch left will initiate left-wing-down trim and moving the switch right
will initiate right-wing-down trim. Pressing down on the switch will
disconnect the autopilot if the autopilot was engaged. Neutral trim is
indicated by the alignment of the line etched on the control yoke with
the centering indication marked on the instrument panel. The aileron
trim also provides a secondary means of aircraft roll control in the
event of a failure in the primary roll control system not involving
jammed ailerons. Aileron trim operates on 28 VDC supplied through
the 2-amp ROLL TRIM circuit breaker on Main Bus 1.
7-14 P/N 13999-002 Info Manual
September 2011