ENGINE MANUAL
IAE50R – AA
E1.01.05 – E
Issue date: 25.Jan.2018
Page: 19-2
Revision no: 9
19.1
Engine Control System
The electrical system provided from AE includes the Engine control unit (ECU), sensors and
actuators for controlling the engine.
The engine control unit activates the ignition and injection based on the information of
speed, manifold pressure and some correcting factors. The actuators are supplied from the
aircraft power supply bus/buses. The low side paths of the actuators are controlled by the
ECU. Communication interface of the ECU are CAN-Bus-Interface and RX/TX-Interface. A
signal output (TX-Output) is available from the ECU to display error warning information to
the pilot by means of a coded flashing light ( Details described in the designated chapter).
19.1.1
Fuel injection
19.1.1.1
Injection Timing
The throttle body assembly, including the throttle valve, injector, and fuel rail, is attached
to the rotor housing via a spacer block with tapping points for oil feeds and MAP sensors.
The correct fuel injection timing is provided by the same speed sensors, and the
appropriate amount of fuel is delivered by controlling the “on–time” of the injector. The
“on–time” is determined by the ECU reflect engine speed, manifold pressure and ambient
conditions.
19.1.1.2
Load Demand
Duplicated Manifold Absolute Pressure (MAP) sensors measure the load demand on the
engine. These sense the air pressure inside the throttle body as determined by the
combination of engine speed, throttle setting and ambient pressure. If either sensor should
become defective, the ECU will automatically select the other and provide a cockpit
indication via a coded error warning signal.
19.1.2
Ignition System
19.1.2.1
Ignition Triggering
Two steps in the rim of the flywheel, nominally 180° apart, trigger each timing sensor. If a
sensor should become defective the ECU will automatically select the other and provide a
cockpit indication via a coded error warning signal.
19.1.2.2
Ignition
The spark plug pair are fired simultaneously, each by its own coil, triggered by the output
from the ECU.
