曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
23. process [ 'prouses ] n. ; vt. 过程; 处理
24. arrival [ ' raivl ] n. 到达
25. approach procedure 进近程序; 进场着陆程序
26. inbound course [ ' inbaund ] 归航航道
27. preset course error 预调航道误差
28. beam error rate [ bi:m ] 波束误差率
29. disappear [ dis' pi ] vi. 消失; 隐去
TEXT
[1] In the normal sequence, the F/D is used for TAKEOFF. The autopilot
is engaged shortly after TAKEOFF, and the LNAV, VNAV mode of A/P
are used in cruise, climb and descent. The approach and AUTOLAND
are made using both A/P and F/D. Finally a dual channel A/P
GO-AROUND is made. We will introduce TAKEOFF, LNAV, VNAV,
and AUTOLAND in lesson 39 and lesson 40.
[2] Figure 39-1 illustrates the TAKEOFF operational procedure.
Fig. 39-1 TAKEOFF
A. Initial condition and preflight --------- After power is applied to the
airplane, the IRS is placed in the NAV position. The airplane must not be
moved until the IRS has completed alignment. During this time, the
preflight operations are performed on the other systems. For the DFCS,
assure the stab trim (A/P)cutout switch is in NORMAL, engage the yaw
damper, check the FMS WARN annunciators and preflight of the FMC.
Place both F/D switches to ON. A roll and pitch mode must be selected
to bring the F/D bars into view. This occurs when TO/GA is selected.
The master light located adjacent to the F/D switch illuminates. The
DFCS status annunciation is F/D. Select the runway heading with the
heading knob and the desired bank angle limit. Set V2 (Scheduled Target
Speed) speed with speed knob on the MCP. The A/S cursor drives to the
set speed. Set the MCP altitude to the ATC clearance altitude.
B. Takeoff Roll -------- Place the A/T engage switch on the MCP to
ARM, then the A/T switch is solenoid held in the ARM position and the
A/T green light is illuminated. Pressing the TO/GA switch engages the
F/D and A/T in the takeoff mode. The flight director bars come into view,
TO/GA and N1 (Low Pressure Rotor Speed) are annunciated. The thrust
mode annunciation annunciates TO. As the takeoff roll begins and prior
to reach 60 knots, the throttle are automatically adjusted to the target N1.
In roll, the F/D commands wing level at a maximum of 4 degrees of bank,
the F/D does not provide runway steering or rotation commands. At the
airspeed greater than 64 knots, the F/D commands 15 degrees nose up.
The A/T goes into throttle hold (THR HOLD) and the annunciation is
A/T-THR HOLD. Throttle hold remains for 17.5 seconds after liftoff
until a radio altitude of 400 feet is attained. The power is removed from
the throttle servos to ensure no A/T movement during the takeoff phase.
C. Liftoff -------- After liftoff (unsquat), the F/D transfers from a 15
degrees nose up command to a speed command. The initial speed target
is V2 plus 20 knots, however, the MASI (mach airspeed indicator)cursor
is at V2. The transition to speed control is a function of altitude rate
beginning at 600 fpm (feet per minute) and completed at 1200 fpm.
Maximum speed command is limited to the flap placard speed until the
MCP speed is reached. The F/D bank angle is limited to 8 degrees and
roll rate to 4 degrees/second below a radio altitude of 400 feet. At radio
altitude greater than 400 feet, the master light associated with the F/D
ON is extinguished. The bank angle limit is increased to the MCP
selected bank angle. At UNSQUAT PLUS 17.5 seconds and a radio
altitude greater than 400 feet, the A/T changes to and annunciates ARM.
Other DFCS and A/T mode may be selected. However, ALTITUDE
ACQUIRE is inhibited prior to a radio altitude of 800 feet.
D. Climb -------- pressing the VNAV and LNAV switch engages the
FMC for vertical and lateral guidance. LNAV and VNAV are
annunciated. Pressing the VNAV switch also initiates the N1 mode. The
N1 mode switch illuminates, and N1 is annunciated for A/T and CLB is
annunciated for thrust. When the radio altitude is greater than 400 feet,
the A/P may be engaged in CMD. The master light associated with the
A/P in CMD is illuminated. When the A/P is engaged, the speed trim
system is disengaged and auto stabilizer trim is engaged.
Fig. 39-2 LNAV
[3] Figure 39-2 illustrates LNAV operation sequence. LNAV is the
normal lateral navigation cruise mode for the DFCS. The lateral flight
profile commands are supplied from the FMCS based on the navigation
and performance data bases and the active flight plan. The FMCS inhibits
LNAV engage when airplane on the ground.
A. Initial condition -------- after TAKEOFF, the radio altitude is greater
than 400 feet.
B. LNAV (Lateral navigation)----- Press LNAV switch to engage LNAV.
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航空工程英语基础（中英文对照）(67)
