Systems Guide

Aerosoft
Airbus A320/A321
SYSTEMS
Systems guide
Vol
4
04-03-58
28 October 2014
POWER PLANT
The Airbus A320 and A321 are powered by two CFM56 or IAE V2500 turbofan engines. Though these engines
have slightly different characteristics, these differences are hard to notice for the crew as they are controlled by
FADEC systems. The type rating of an Airbus pilot does not even mention the engine type.
FADEC
The Full Authority Digital Engine Control system (also called the Electronic Control Unit ECU) performs these
functions:
 Gas Generation Control (fuel flow, acceleration, idle settings)
 Engine Limit Protection (overspeed and EGT monitoring)
 Power Management (thrust rating)
 Automatic Starting Sequence
 Thrust Reverser Control
 Fuel Recirculation Control
 ECU Cooling
 Detection, Isolation and Recording of failures.
THRUST CONTROL SYSTEM
Thrust Control is managed by the FADEC on each engine. Thrust selection is done by means of the thrust levers
when in manual mode or by the FMGS when in automatic mode. Thrust rating limit (maximum amount of power)
is provided by the thrust lever position.
THRUST LEVERS
In automatic mode the trust levers should
be seen as mode selectors and in many
flights the throttles are not touched in the
complete flight (from shortly after take-off
to shortly before landing) and stay in CLIMB
mode the whole flight.
The thrust levers can only be moved
manually between 5 detents (stops) over 4
operating segments. Auto throttle is on only
active in the range between idle and climb
(including bit detents). Thrust Rating limit is
computed from the thrust lever position,
when between detents the FADEC will
select the rating limit of the higher detent.