FLIGHT MODE ANNUNCIATOR
The FMA is located at top of the PFD Screens. It is divided into 5 columns which indicate the operational modes of the AP, A/THR and FD. the columns are numbered from the left and indicate the following.
FMA OVERVIEW
Mode change on the FMA are called by the PF, then cross -checked and confirmed by the PNF.
As a means of attracting the crew's attention to change on the FMA, a white box is displayed for 10 seconds around each new annunciation, in the case of a mode reversion, e.g. LOC/GS to HDG/V/S, the box is displayed for 15 seconds and is accompanied by a "triple click " aural warning
REVERSION AND AUTOMATIC SPEED PROTECTION MODES
A mode reversion is when the AP and/or A/THR modes change automatically to ensure mode compatibility. The new mode is displayed on the FMA and depending upon the reversion, is sometimes accompanied by triple click, when a mode reversion occurs, the FMA should be announced in the normal manner. If required. Take appropriate action to correct the flight path.
In some circumstances, to prevent an inappropriate speed trend the AP may temporarily abandon a vertical speed target to prevent the speed from either reducing below VLS or from exceeding VMAX, In this case, the FMA MODES do not change, however the indication on the FMA pulses and is boxed amber, and a triple click is generated FCOM 1.22.30 Refers.
TRIPLE CLICK
The "triple click " is an aural alert designed to draw the pilots attention to the FMA, the FMA Highlights a mode change or reversion with a box around the new mode and the pulsing of its associated FD bar.
The triple click aural alert also occurs in the following less common cases
• Reversion to CLB (OP CLB) Mode, if the pilot selects a speed on the FCU while in SRS.
• inhibition of V/S mode engagement, if the pilot pulls the V/S knob while in ALT.
•Automatic speed protection at VLS/VMAX if the V/S target is not followed because the selected target is too high,
INTERFACE
The AP can be handled in two ways : "selected " for short -term guidance and "managed " for long term guidance - short -term guidance applies to actions that are carried out by the pilot on the FCU, e. g. In response to an ATC instruction long- term guidance applies to instructions that have been programmed into the FMGS, e, g, the flight plan, whichever method of management is being used, the crew must monitor AP performance through FMA Indicators and aircraft response.
FCU HANDLING
When making selections on the FCU, Locate the appropriate selector and then make any change with reference to the PFD, ND or FMA as appropriate, this method ensures that the correct target is set for the AP and /or FD.
When the AP Is flying the aircraft, the PF makes the selections on the FCU. When hand flying the aircraft, the PF requests the PNF to make the required selections on the FCU.
FLIGHT DIRECTOS
The FDs are normally selected on when the aircraft is being flown the AP the FDs give a visual indication of the AP performanc if it is suspected that the AP/FD is not giving correct or accurate guidance disconnect the AP request the PNF to select both FDs off and fly the aircraft manually, in this case, the FPV should be selected.
When flying manually either follow the FDs Or direct the PNF to select them both off. This ensures that the A/THR, if active, will operate in speed mode.
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