CHAPTER 2
Systems
2.1 POWER PLANT SYSTEMS
2.1.1 Engines. The aircraft is powered by two General Electric F414-GE-400 engines. The engines
are low bypass, axial-flow, twin-spool turbofans with afterburner. The three stage fan (low pressure
compressor) and the seven stage high pressure compressor are each driven by a single stage turbine.
The basic functions are supported by the engine driven accessory gearbox which drives the engine fuel
pump, variable exhaust nozzle (VEN/start) fuel pump, lubrication and oil scavenge pump, engine fuel
control, and alternator. Fuel flow from the VEN/start pump is used to drive the VEN actuator and to
provide initial fuel pressure for main engine start.
The uninstalled military thrust (MIL) of each F414-GE-400 engine is approximately 13,900 pounds
with maximum afterburner thrust (MAX) in the 20,700 pound class.
An inlet device is installed in each engine intake to reduce the aircraft radar signature and to
improve survivability.
2.1.1.1 FADEC - Full Authority Digital Engine Control. Engine operation is controlled by a full
authority digital engine control (FADEC), mounted on the engine casing. Each FADEC computer has
two central processor units, channel A (CH A) and channel B (CH B), and is integrated with the
Mission Computers (MCs), flight control computers (FCCs), and throttles. Normally, both FADEC
channels monitor engine and control system operation with one channel in control and the other in
standby. The channel currently in control is boxed on the SUPT MENU/ENG display.
In the event of a control system failure, the FADEC automatically selects the channel with better
capability. Manual FADEC channel transfer can be commanded by selecting the CH A or CH B
pushbutton on the ENG display. When the throttle is at or above IDLE, the FADEC transfers control
to the other channel only if the requested channel's health is no worse than the channel in control.
FADEC software implements the engine control schedules by modulating fuel flow and engine
geometry for the current flight conditions and the ²requested² throttle setting. With the throttles
matched, engine parameters may vary significantly between the engines as control schedules are
adjusted for optimum performance. Therefore, a mismatch between engine parameters is not a sign of
degraded performance as long as ENG STATUS is NORM. FADEC cooling is provided by the fuel
system.
2.1.1.1.1 FADEC Power Sources. Prior to first engine start, the battery is used to power CH A of
both FADECs. When N2 reaches 10% rpm during start, the engine driven alternator comes online and
powers both channels of its corresponding FADEC. When an aircraft generator comes online (N2
greater than 60%), the aircraft's electrical system provides power to both channels of the other FADEC
as well. With both engines operating, each engine driven alternator is the primary source of FADEC
power with the aircraft's 28 vdc essential bus as backup. When both channels of a FADEC are powered
after initial start, the FADEC automatically switches operation to the channel which was not in control
during the last flight/engine run.
A1-F18EA-NFM-000
I-2-1 ORIGINAL
Ten seconds after reaching idle power, the FADEC attempts to switch to the 28 vdc essential bus to
verify that backup power is available. If backup power is inadequate/inoperative, the FADEC declares
a channel degrade (dual channel lineout) and sets a 6A8 or 6C8 MSP code (L or R FADEC/aircraft 28V
fail). These degrade indications appear if the first engine is started with the corresponding GEN switch
OFF, and requires a FADEC reset to restore normal engine indications.
2.1.1.1.2 Engine Status. Engine status is reported by the FADEC and appears on the ENG
STATUS line of the ENG display. The levels of engine performance capability, listed in descending
order, are:
NORM Engine performance is normal
PERF90 10% or less thrust loss and/or slower engine transients. Afterburner is not
inhibited
AB FAIL No afterburner capability
THRUST Engine thrust is limited to between 40% and 90% and significantly slower
transients
IDLE Engine is limited to idle power only
SHUTDOWN Engine automatically shut down
2.1.1.1.3 FADEC/Engine Degrades. FADEC/engine degrades fall into two categories: minor failures
which do not affect engine operability and significant failures that do affect engine operability.
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本文链接地址：NATOPS Flight Manual 飞行手册 1(29)
