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The FMS approach phase should be activated unless it has automatically activated. Considering the conditions of FINAL APP mode engagement described in paragraph 5.2.2 above, it is recommended to conduct the descent so that the altitude of the vertical flight path intercept point is reached slightly before that point. In the above example for Katmandu the aim would be to be at 9960 ft slightly before NOPEN in ALT mode with S speed and CONF 2. Before NOPEN, the crew will select APPR and check FINAL blue is displayed on FMA and that the blue descent arrow is displayed close to NOPEN.
Depending where the FINAL APP mode is planned to activate, some kind of decelerated approach can be considered. The aircraft configuration must be compatible with the airspeed constraints to cope with the flight path radius of turns. The airline documentation should also define the point during the approach where landing configuration and stabilized Vapp is expected to be established.
The use of the TRK/FPA display is relevant for straight in approaches. For RNP AR approaches with turns in the final approach segment, the use of FD with cross bars is recommended. Cross bars are also better for the crew to identify AP/FD malfunctions.
When the FINAL APP mode activates, the crew will check that the aircraft is guided on an appropriate vertical flight path (attitude, V/S) and will select the go around altitude on FCU. During the final approach segment, the crew will monitor the L/DEV and the V/DEV and check that altitude constraints are observed. With the present FMGC logic, the AP will disconnect at DA-50ft and the FD mode will revert to HDG-V/S. For future FMGC standards, Airbus investigates the possibility to keep AP in FINAL APP mode below DA. When visual conditions are reached, the PF will disconnect the AP and both pilot will select FD OFF.
7.2.4.3 MISSED APPROACH PROCEDURE
At DA, at the latest if visual conditions are not met, a go around must be initiated.
For aircraft without the automatic NAV mode reengagement at GA initiation, it is essential to
immediately reengage the NAV mode manually.
The missed approach is quite standard, but as required by the flight path design, the crew will
monitor that the correct speed constraints are taken into consideration or will select the
appropriate speed on FCU to fly the RF legs.
The aircraft clean up must be adapted to the speed constraints.
Reaching the transition altitude, the L/DEV indication disappears.
7.2.5 ABNORMAL PROCEDURES
The flight crew must be ready to react to abnormal situations that may require specific procedures and training in RNP AR environment.
7. RNP AR Operations and Training
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7.2.5.1 ENGINE FAILURE
In case of engine failure, it is recommended to keep AP in command (except in approach on SA aircraft with FMGC standard that prohibits it). During departure or missed approach, the crew may observe a lateral excursion when the engine fails or during acceleration and clean up with OEI, which normally remains within the 1XRNP limit. If the 1xRNP limit is going to be exceeded, the PF will disconnect AP, and correct manually increasing slightly the bank angle and using the L/DEV indication to converge towards the FMS flight path. When converging, the AP can be reengaged.
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本文链接地址：getting to grips with RNP AR Required Navigation Performance(31)
