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时间:2011-02-10 14:53来源:蓝天飞行翻译 作者:admin
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Due to a high level of FADEC redundancy, most minor control system failures do not cause any
degradation in engine performance (ENG STATUS remains NORM). Cockpit indications for these
types of failures are slightly different depending on whether the aircraft is inflight or on the ground.
Inflight -
a. FADEC and BIT advisories.
b. ENG STATUS - NORM.
c. OP GO indication for the affected engine channel on the BIT/HYDRO MECH display.
On the ground or below 80 KCAS after landing -
a. FADEC and BIT advisories.
b. ENG STATUS - NORM.
c. DEGD replaces OP GO for the affected engine channel on the BIT/HYDRO MECH display.
d. Both CH A and CH B lined out on the ENG display.
A FADEC OP GO or DEGD with an ENG STATUS of NORM is an indication of a loss of control
system redundancy and not of a loss of engine operability. Therefore, a FADEC OP GO inflight should
be considered informative and should not mandate a mission abort. However, on the ground, the
A1-F18EA-NFM-000
I-2-2 ORIGINAL
FADEC DEGD and dual channel lineout indications are intended to prevent takeoff with a known loss
of redundancy and maintenance action is required. Therefore, takeoff with a FADEC DEGD indication
(dual channel line out) is prohibited.
Significant failures which do cause degradation in engine performance have the following indications
both inflight and on the ground:
a. L or R ENG caution and voice alert.
b. FADEC and BIT advisories.
c. ENG STATUS change on the ENG display.
d. DEGD indication for the affected engine channel on the BIT/HYDRO MECH display.
e. Both CH A and CH B lined out on the ENG display.
2.1.1.1.4 FADEC Reset. When a throttle is OFF, the corresponding FADEC uses a channel change
request as a FADEC software reset. FADEC reset capability is provided to clear a DEGD indication
which was caused by a momentary FADEC fault (e.g., startup power transient). A FADEC reset should
only be performed for DEGD indications which occur on the ground and which do not result in a
change of ENG STATUS. For a FADEC OP GO inflight, engine shutdown and FADEC reset is not
recommended as the engine is functioning normally. In all other circumstances, a FADEC reset should
not be attempted, particularly airborne, as any degrade in ENG STATUS is most likely indicative of
the failure of a mechanical component. Under these conditions, the engine may fail to restart following
a shutdown and FADEC reset attempt.
2.1.1.1.5 Ignition System. The FADEC provides simultaneous control of the main and afterburner
igniters via the engine driven alternator and ignition exciter. Ignition (both main engine and
afterburner) is commanded when:
N2 rpm is between 10% and 45% during engine start.
a. Flameout occurs.
b. Throttle is advanced into afterburner, remaining on until afterburner light off is sensed.
c. The trigger is squeezed (second detent) for the gun, any A/A weapon, or when the pickle is
pushed for any selected A/G missile/rocket. Ignition remains on for 5 seconds.
2.1.1.1.6 Oil Pressure Sensing System. The oil pressure sensing system utilizes an oil pressure
transducer and a separate oil pressure switch. The transducer provides an oil pressure value for display
in the cockpit. The oil pressure switch provides an additional source to confirm the presence of oil
pressure if the oil pressure transducer fails.
If a L or R OIL PR caution is set with a valid cockpit readout, actual engine oil pressure is below
scheduled limits. If the cockpit readout is zero with no caution set, the oil pressure transducer has
failed and the pressure switch is inhibiting the caution.
2.1.1.1.7 Engine Idle Schedules. Each FADEC modifies engine idle schedules based on weight on
wheels (WonW), aircraft flight condition, engine bleed demand, and environmental control system
(ECS) mode of operation. The purpose of idle scheduling is to make sure that engine bleed output is
always sufficient to run the ECS, particularly the aircrew onboard oxygen generating system (OBOGS).
A1-F18EA-NFM-000
I-2-3 ORIGINAL
Baseline idle schedules are used during normal engine operation and moderate environmental
conditions, and are set as a function of pressure altitude and WonW. With WonW and airspeed below
80 knots, the FADEC commands ground idle by reducing the engine compressor discharge pressure
(CDP) (typically a slight decrease in N2 rpm) from the inflight idle setting. The throttle handle angle
(THA) for ground and inflight idle are identical.
Alternate idle schedules are used when engine bleed demands are high (e.g., hot ambient
temperatures, high ECS output, RECCE configuration, or anti-ice or rain removal operation). When
alternate idle schedules are active, the FADEC increases the minimum CDP that is commanded at idle
 
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本文链接地址:NATOPS Flight Manual 飞行手册 1(30)