.
a published MDA(H) used as a decision altitude.
When either of the above minima are not specifically authorized, use the MDA(H) specified for the instrument procedure.
The following diagram illustrates an approach procedure containing DA(H) and MDA(H) minimums for approaches using LNAV/VNAV or LNAV only.
CIRCLE - TO - LAND STRAIGHT-IN LANDING RWY 28R
LNAV/VNAV LNAV
DA(H)740’(727’)
MDA(H) 1000’(987’) ALS out
Max Kts ALS out MDA(H)
A
90
RVR 60 or 11/4
RVR 40or 3/4
1000’(987’) -2
11/2
B
120 21/2
RVR 50or 1
2
C
140
1140’(1027’) -3
21/2 3
D
21/4
165
1160’(1147’) -3
Note: Some non-ILS approaches specify a VNAV DA(H). Regulations may require use of the autopilot in the VNAV PTH mode to permit use of the DA(H).
737-300 - 737-500
When reaching the DA(H) or MDA(H), be prepared to disengage the autopilot and
autothrottle and land or execute an immediate go-around.
737-600 - 737-900
When reaching the DA(H) or MDA(H), be prepared to disengage the autopilot,
disconnect the autothrottle and land or execute an immediate go-around.
Note: If using an MDA(H), initiating a missed approach approximately 50 feet above MDA(H) may be necessary to avoid descending below the MDA(H) during the missed approach, if required for the procedure or by the regulatory authority.
The pilot monitoring should expand the instrument scan to include outside visual cues when approaching DA(H) or MDA(H). Do not continue the approach below DA(H) or 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 DA(H) or MDA(H) or any time thereafter, if any of the above requirements are not met, immediately execute the missed approach procedure.
When suitable visual reference is established, maintain the descent path to the flare. Do not descend below the visual glide path. While VNAV PTH guidance may still be used as a reference once the airplane is below DA(H) or MDA(H), the primary means of approach guidance is visual.
Note: VNAV path guidance transitions to level flight once the missed approach fix is passed.
Copyright . The Boeing Company. See title page for details.
5.50 FCT 737 (TM) October 31, 2006
Simulated Instrument Approach Using VNAV
To maintain proficiency, crews may practice instrument approach using VNAV procedures while flying ILS approaches as follows:
.
ensure the ILS is tuned and identified and the ILS raw data is monitored
throughout the approach
.
track the localizer using VOR/LOC or LNAV as the roll mode
.
use VNAV as the pitch mode to track the GP angle. The charted GP angle
normally coincides with the ILS glide slope angle
.
disengage the autopilot by the minimum altitude specified in the
Limitations chapter of the FCOM.
Note: Limit the use of the above technique to VMC weather conditions.
In ambient temperature conditions warmer than ISA standard, the airplane may remain slightly high relative to the ILS glide slope, and in temperatures colder than ISA standard, the airplane may remain slightly lower than the ILS glide slope. Discontinue use of this technique and manually track the localizer and glide slope if localizer or glide slope deviations become unacceptable.
Approaching intercept heading
Flaps 5
.
Flaps 5
.
Localizer/Final approach course capture
Final approach course . heading
Intercept heading
Radios tuned
.
Deviation pointers shown
.
Select APP
.
Flaps 1 .
Glide path intercept
On RADAR vectors
HDG SEL
.
Pitch mode (as needed)
.
Enroute to fix
LNAV or other roll mode
.
VNAV or other pitch mode
.
Landing flaps (2 engine)
.
Set missed approach altitude
.
Do the Landing checklist
.
Fix
(LOM, MKR, DME)
Verify crossing altitude .
Glide path alive
Gear down
.
Flaps 15 (final flap for 1 engine)
.
Arm speedbrake
.
Minimum use height forsingle autopilot
(see limitations chapter)
Disengage A/P and A/T .
Approach and Missed Approach 中國航空網 m.k6050.com 航空翻譯 www.aviation.cn 本文鏈接地址：737機組訓練手冊 Flight Crew Training Manual FCTM(77)
