787 Flight Crew Operations Manual
DO NOT USE FOR FLIGHT
Engines, APU -
Engine System Description
Copyright © The Boeing Company. See title page for details.
D615Z003-TBC 7.20.13
In–Flight Start
In-flight start envelope information is displayed on the EICAS display when an
engine is not running in flight (N2 RPM below idle RPM) or when an engine is
shut down in flight and the respective engine fire switch is not pulled. The in-flight
start envelope indicates the airspeed range necessary to ensure an in-flight start at
the current flight level. If the current flight level is above the maximum start
altitude, the maximum start altitude and respective airspeed range are displayed.
Secondary engine indications are automatically displayed in flight when an engine
is not running (N2 RPM is below idle with corresponding FUEL CONTROL
switch in RUN) or when a FUEL CONTROL switch is moved to CUTOFF. A
starter assist indication (X-START) is displayed below the N2 indication if
airspeed is below that recommended for a windmilling start.
For in–flight starts, autostart makes continuous start attempts until the engine
either starts or the pilot aborts the start attempt by positioning the FUEL
CONTROL switch to CUTOFF (and positioning the START switch to NORM if
it was a starter assisted attempt).
During a windmilling in–flight start, the EEC monitors engine parameters to
provide the best fuel schedule to ensure the shortest possible start time.
(Refer to Engine In–Flight Start, QRH, Non Normal Checklists Chapter 7, for the
in–flight engine start procedure.)
Engine Ignition
Each engine has two ignitors. The EEC automatically selects the appropriate
ignitor(s) for successive engine ground starts. Dual ignitors are always used for
in–flight starts.
Aircraft supplied DC power is the normal power source for ignition. Standby
power provides a backup power source for energizing the ignitors.
Auto–Relight
[Option – GE engines]
Engine auto-relight protection is provided for flameout and sub-idle stall recovery.
There is no manual continuous ignition selection or automatic continuous ignition
function. The auto-relight function is activated on the ground and in-flight
whenever an engine is at or below idle with the FUEL CONTROL switch in RUN.
If an engine flameout (rapid decrease in N2) or an engine rollback (N2 falls below
idle after the engine has achieved idle following the previous start) is detected, the
EEC switches on both ignitors in the respective engine in an attempt to recover the
engine. The ignitors are switched off when the engine again reaches idle.
February 15, 2010
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