October 31, 2003 FCT 757 (TM) 5.41
Approach Preparations for using V/S
Select the approach procedure from the ARRIVALS page of the FMC. Tune and identify appropriate navaids. If additional waypoint references are desired, use the FIX page. To enable proper LNAV waypoint sequencing, select a straight-in intercept course to the FAF when being radar vectored to final approach. Verify/enter the appropriate RNP and set the MDA(H) using the baro minimums selector. If required to use MDA(H) for the approach minimum altitude, the barometric minimums selector should be set at MDA + 50 feet to ensure that if a missed approach is initiated, descent below the MDA(H) does not occur during the missed approach.
Final Approach using V/S
Approaching intercept heading, select flaps 5 and ensure LNAV or other appropriate roll mode is armed or engaged. Approaching the FAF (approximately 2 NM), select gear down and flaps 20 and adjust speed. Set the MCP altitude window to the first intermediate altitude constraint, or MDA(H) if no altitude constraint exists.
Note: If desired altitude is not at an even 100 foot increment, set the MCP altitude to the nearest 100 ft. increment below the altitude constraint or MDA(H).
Just prior to FAF, select landing flaps, reduce to final approach speed and complete the Landing checklist. If the charted FAF is too close to the runway to permit a stabilized approach, consider establishing final approach pitch mode and configuring for approach and landing earlier than specified in the Operations Manual procedure.
At or after the FAF, select V/S mode and descend at appropriate vertical speed to arrive at the MDA(H) at a distance from the runway (VDP) to allow a normal landing profile. Initial selection of an appropriate V/S should be made considering the recommended vertical speeds that are published on the approach chart, if available. These recommended vertical speeds vary with the airplane's ground speed on final approach. If no recommended vertical speeds are available, set approximately -700 to -800 fpm.
When stabilized in a descent on final approach, use one of the following techniques to make small incremental changes to the resulting vertical speed to achieve a constant angle descent to minimums. There should be no level flight segment at minimums.
Several techniques may be used to achieve a constant angle path that arrives at MDA(H) at or near the VDP:
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the most accurate technique is to monitor the VNAV path deviation
indication on the map display and adjust descent rate to maintain the
airplane on the appropriate path. This technique requires the path to be
defined appropriately on the LEGS page and that the header GPx.xx is
displayed for the missed approach point or there is a RWxx, MXxx, or
named waypoint on the legs page with an altitude constraint which
corresponds to approximately 50 ft. threshold crossing height. When this
method is used, crews must ensure compliance with each minimum
altitude constraint on the final approach segment (step down fixes).
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select a descent rate that places the altitude range arc at or near the
stepdown fix or visual descent point (VDP). This technique requires the
stepdown fix or MDA(H) to be set in the MCP and may be difficult to use
in turbulent conditions. See the Visual Descent Point section for more
details on determining the VDP.
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using 300 feet per mile for a 3° path, determine the desired HAA which
corresponds to the distance in NM from the runway end. The PNF can
then call out recommended altitudes as the distance to the runway changes
(Example: 900 feet - 3 NM, 600 feet - 2NM, etc.). The descent rate should
be adjusted in small increments for significant deviations from the
nominal path.
Be prepared to land or go-around from the MDA(H) at the VDP. Note that a normal landing cannot be completed from the published missed approach point on many instrument approaches.
Approximately 300 feet above the MDA(H), select the missed approach altitude. Leaving the MDA(H), disengage the autopilot and disconnect the autothrottle. Turn both F/Ds OFF, then place the PNF’s F/D ON. This eliminates unwanted commands for the PF and allows continued F/D guidance for the PNF in the event of a go-around when pitch or roll mode is changed. Complete the landing.
Minimum Descent Altitude/Height (MDA(H))
The pilot not flying should expand the instrument scan to include outside visual cues when approaching MDA(H). Do not continue the approach below MDA(H) unless the airplane is in a position from which a normal approach to the runway of intended landing can be made and suitable visual reference can be maintained. Upon arrival at MDA(H) or any time thereafter, if any of the above requirements are not met, immediately execute the missed approach procedure.
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本文链接地址：757 Flight Crew Training Manual 机组训练手册(62)
