AIRPLANE
OPERATIONS
MANUAL
POWERPLANT
REVISION 41
2-10-40
Page
7
Code
01
Copyright © by Embraer. Refer to cover page for details.
FLAMEOUT DETECTION/AUTORELIGHT
Flameout and autorelight detection logic within the FADEC detects an
engine flameout and attempts an automatic relight before the engine
loses power, if N2 is higher than 53%. In the event that a relight cannot
be successfully executed, the FADEC commands an engine shutdown.
During in-flight restarts, both ignition systems are energized.
N1 REVERSIONARY CONTROL MODE
The FADEC provides a reversionary control mode to accommodate a
total loss of fan-speed (N1) signal.
The FADEC stores data on the correlation between N1 and N2 of an
average engine in its non-volatile memory, and in the event that all N1
signals are lost, it will control thrust governing N2 speed.
The engine control system is capable of modulating thrust in response
to thrust lever movement in the reversionary control mode. However,
transient response times may be greater, minimum thrust may exceed
flight idle thrust and maximum thrust may be less than that expected
during normal control operation.
This mode is evident to the pilot due to the absence of N1 indication on
the EICAS.
FADEC INPUTS SELECTION AND FAULT
A
CCOMMODATION
For every FADEC input, there is a selection and fault accommodation
logic, based on the inputs to both FADECs of the same engine.
The engine control system is highly fault tolerant. Because of
redundant sensor inputs and outputs, the control system can
accommodate multiple faults with no degradation in engine response.
The fault accommodation philosophy is to maintain operation on the
controlling FADEC for as long as possible before transferring control to
the standby FADEC.
For every detectable fault, the FADEC provides a signal to the EICAS
for the alerting message or to the Central Maintenance Computer for
the maintenance message.
To Next Page
Loading...
