曝光臺 注意防騙 網曝天貓店富美金盛家居專營店坑蒙拐騙欺詐消費者

and the engine fuel boost pump so that fuel pressure
is readily available to the spray bars for AB light-off.
2.4.3 Main Fuel Pump. The main fuel pump is a
two-stage pump that receives fuel flow from the engine
fuel boost pump. It provides additional fuel pressurization
and transmitsm echanical-gear-drivenp ower to the
MEC from the gearbox.
2.4.4 Main Engine Control. The MEC is a fueloperated,
bydromechanical fuel flow regulator that operates
in tandem with the main fuel pump and is capable
of operating in two modes. In the primary mode, it
meters main fuel flow as commanded by the AFK and
provides VSV scheduling. The secondary mode hydromechanically
meters main fuel flow to govern Nz
speed based on pilot throttle commands and provides
basic engine control except for AFTC fan speed limiting.
VSVs aerodynamicallym atch high- and low-pressme
compressosr tagesb y changingt he angle atw hich airflow
enterst he compressorro tor blades.T he MIX containst he
schedulingm echanisma nd providesm eI pressureto vary
VSV positioning. A flexible mechanical cable provides
feedback from the compressor stator to the MEC.
2-21 ORIGINAL
NAVAIR M-FlUADELECTRICAL
FUEL
HYDRAULlC
-
---
FUEL SUPPLY
ORIGINAL
Figure2 -17. EngineF uelS ystem
2-22
NAVAIR Ol-FI4AAD-I
2.4.5 Afterburner Fuel Pump. The AB fuel pump
is a centrifugal gear-driven pump that receives fuel from
the engineb oost pump, increasesp ressure,a nd delivers
tie1 to the AB tieI control. During non-AB operation,
Abel is circulated between the AB fuel control and the
engine boost pump; the AB fuel pump impeller runs dry
with the bearings lubricated by the engine oil system.
Failureofan AB fuelpump will result inan AB blowout.
2.4.6 Afterburner Fuel Control. The AB fuel control
is a fuel-operated,e lectrohydromechanicaul nit that
regulatest ie1 flow in responseto AFTC schedulinga nd
compressor discharge pressure. Fuel pressure from the
AB fuel control provides on-off signals to the AB fuel
Pump.
The AB fuel control splits fuel flow into three metered
streams (local, core, and fan) on a sequential basis
into the AI3 manifolds for distribution through spraybars
in the AB duct. Throttle commands initiate local fuel
flow and AB ignition (minimum AB). Once local fuel
flow and flame are established, core fuel flow commences.
As maximum core fuel flow is established, fan
fuel flow commencesa nd increasesu ntil maximum AB
is achieved. The transitions between local, core, and fan
fuel flow are smooth and unnoticed (Figure 2-18). During
non-AB operation, fuel flow is circulated through
the AB manifolds to prevent thrust lags and surges when
AB is initiated.
1 WARNING 1
a Zero or negative-g flight longer than 10
seconds in AB or 20 seconds in MIL or
less will deplete the fuel sump tanks (cells
3 and 4), resulting in flameout of both
engines.
a To prevent engine instability and/or flameout,
avoid holding zem or negative g when
doingalow-altitude,maximum-thrust acceleration.
a With fuel in feed group below 1,000
pounds, AB operation could result in AB
blowout.
Note
Fuel dump operations with either engine in
AB are prohibited. The fuel dump mast can
be torched.
2.5 THROTTLES
Two throttle levers for regulating engine thrust are on
the left console of the forward cockpit. Unrestricted
engineo perationu nder independenct ontrol is afforded;
however, normal symmetric thrust control is provided
by collective movement of the throttle levers. Numerous
engine control and subsidiary functions are performed
by movement of the throttle levers within the full range
of travel as shown in Figure 2-19. The forward and aft
throw of each throttle lever in the quadrant is restricted
by hard detents at the OFF, IDLE, MIL, and MAX (AB)
positions. At the OFF and IDLE detents, the throttles are
spring loaded to the inboard position. At the MIL detent,
the throttles can be shifted outboard to the AB sector or
inboard to the basic engine sector ofoperation by merely
overcoming a lateral breakout force. Lateral shifting of
the throttles at the MIL detent does not affect engine
control. Thus, placement ofthe throttleoutboardat MIL
provides a natural catapult detent to prevent unintentional
retarding of the throttles during the launch. This,
however, does not inhibit the selection of afterburner.
The friction control lever on the outboard side of the
quadrant permits adjustment of throttle friction to suit
individual requirements. With the friction lever in the
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：F-14D 飛行手冊 Flight Manual 1(67)