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a depiction of cross track error from the final approach course
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LNAV capability during the missed approach procedure. The approach procedure may be flown using HDG SEL or LNAV for lateral tracking and VNAV, FLCH, or V/S for altitude changes. VNAV is the preferred descent mode when the FMS flight plan is programmed for the intended arrival.
When VNAV is not available, use FLCH for altitude changes greater than 1,000 feet. For smaller altitude changes, V/S permits a more appropriate descent rate. When maneuvering to intercept the localizer, decelerate and extend flaps to 5.
Attempt to be at flaps 5 and flaps 5 maneuvering speed prior to localizer capture.
When operating in speed intervention or the autothrottle SPD mode, timely speed selections minimize thrust lever movement during the approach. This reduces cabin noise levels and increases fuel efficiency. When flaps are extended, select the next lower speed just as the additional configuration drag takes effect.
Delaying the speed selection causes an increase in thrust, while selecting the lower speed too quickly causes thrust to decrease, then increase.
During the approach, adjust the map display and range to provide a scaled plan view of the area. When on an intercept heading and cleared for the approach, select the APP mode and observe the LOC and G/S mode annunciations are armed.
APP mode should not be selected until:
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the ILS is tuned and identified
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the airplane is on an inbound intercept heading
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both localizer and glide slope pointers appear on the attitude display in the
proper position
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clearance for the approach has been received.
The glide slope may be captured before the localizer in some airplanes. The glide slope may be captured from either above or below. Glide slope capture does not occur if the intercept angle to the localizer is greater than 80°. The maximum intercept angle for the localizer is 120°. To avoid unwanted glide slope capture, LOC mode may be selected initially, followed by the APP mode.
CAUTION: When using LNAV to intercept the final approach course, ensure raw data indicates localizer interception to avoid descending on the glide slope with LOC not captured. If needed, use HDG SEL or HDG HOLD to establish an intercept heading to final approach course.
Final Approach
The pilots should monitor the quality of the approach, flare, landing and rollout, including speedbrake deployment and autobrake application.
At localizer capture, the heading bug automatically slews to the inbound course. For normal localizer intercept angles, very little overshoot occurs. Bank angles up to 30° may be commanded during the capture maneuver. For large intercept angles some overshoot can be expected.
Use the map display to maintain awareness of distance to go to the final approach fix. When the glide slope pointer begins to move (glide slope alive), extend the landing gear, select flaps 20, and decrease the speed to flaps 20 speed.
At glide slope capture, observe the flight mode annunciations for correct modes. At this time, select landing flaps and VREF + 5 knots or VREF + wind correction if landing manually, and complete the Landing checklist. When using the autothrottle to touchdown, no additional wind correction is required to the final approach speed. The pilot not flying should continue standard callouts during final approach and the pilot flying should acknowledge callouts.
When established on the glide slope, set the missed approach altitude in the altitude window of the MCP. Extension of landing flaps at speeds in excess of flaps 20 speed may cause flap load relief activation and large thrust changes.
Copyright . The Boeing Company. See title page for details.
October 31, 2003 FCT 757 (TM) 5.11
Check for correct crossing altitude and begin timing, if required, when crossing
the final approach fix (FAF or OM). There have been incidents where airplanes have captured false glide slope signals and maintained continuous on glide slope indications as a result of an ILS ground transmitter erroneously left in the test mode. False glide slope signals can be detected by crosschecking the final approach fix crossing altitude and VNAV path information prior to glide slope capture. A normal pitch attitude and descent rate should also be indicated on final approach after glide slope capture. Further, if a glide slope anomaly is suspected, an abnormal altitude range-distance relationship may exist. This can be identified by crosschecking distance to the runway with altitude or crosschecking the airplane position with waypoints indicated on the navigation display. The altitude should be approximately 300 feet HAT per NM of distance to the runway for a 3° glide slope.
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本文鏈接地址：757 Flight Crew Training Manual 機組訓練手冊(49)
