Systems Guide

Aerosoft
Airbus A320/A321
SYSTEMS
Systems guide
Vol
4
04-03-13
28 October 2014
AUTOTHRUST ARMING STATUS
When autothrust is OFF the thrust is controlled manually and corresponds to the position of the trust levers.
When autothrust is ARMED and the thrust levers are moved into the A/THR active the autothrust status changes
to ACTIVE. The status is shown on the FMA (blue indicates armed mode and white indicates active mode).
Autothrust is automatically armed during takeoff when thrust levers are in the TOGA or FLX detent.
AUTOTHRUST ACTIVE STATUS
The autothrust system controls thrust only in active status. Both fixed (MCT, CLB, IDLE, THR) and variable thrust
(SPEED, MACH) modes are available in active status.
AUTOTHRUST DEACTIVATION
The autothrust system can be disabled by depressing the FCU A/THR pb or by retarding the throttles to the idle
detent. A single chime and a short amber master caution illumination alerts the pilot.
AUTOTHRUST MODES
FIXED THRUST MODES
 TOGO: Provides fixed maximum
thrust and is only available when
autothrust status is armed.
 FLX: Flex thrust is used for reduced
thrust takeoffs. Thrust is
calculated using the assumed
temperature as set in the MCDU.
 MCT: Provides Maximum
Continuous Thrust at the current
ambient conditions.
 CLB: Provides fixed thrust equal to
the climb thrust rating at current
ambient conditions.
 IDLE: Provides fixed idle thrust.
Only available in active autothrust status. Note the thrust levers can be anywhere in the autothrust
range!
 THR: When the thrust is not TOGA, FLX, MCT or CLB the fixed thrust is called THR.
VARIABLE THRUST MODES
 SPEED: The autothrust system will provide variable thrust to maintain a set speed or a managed speed in
level flight or when the aircraft follows a programmed flight path. Only available when autothrust is
active.
 MACH: Identical to speed mode but not available at low altitudes. The speed mode is automatically
switched to Mach mode (and vice versa) at a preset altitude.
AUTOTHRUST/FLIGHT DIRECTOR/AUTOPILOT
The vertical guidance modes use pitch to maintain a target speed or a specific vertical path. If vertical guidance
modes are used to control a target speed, autothrust uses a fixed thrust mode. If vertical guidance modes are