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A330/A340<br />
FLIGHT CREW<br />
OPERATING MANUAL<br />
The speed or Mach target may be:<br />
‐ Selected on the FCU by the flight crew<br />
‐ Managed by the FMGEC.<br />
<strong>AIRCRAFT</strong> <strong>SYSTEMS</strong><br />
AUTO FLIGHT - FLIGHT GUIDANCE<br />
AUTOTHRUST<br />
When in SPEED or MACH mode, the A/THR does not allow speed excursions beyond the<br />
following limits regardless of the target speed or Mach number:<br />
‐ For a selected speed target, the limits are VLS and VMAX (VMO-MMO, VFE-VLE, whichever<br />
applies)<br />
‐ For a managed speed target, the limits are maneuvering speed (Green Dot, S, F, whichever<br />
applies) and maximum speed (320/0.84-VFE-VLE whichever applies).<br />
In descent, the maximum managed speed targets computed by the FMS are<br />
315/0.83-VFE-VLE, whichever applies.<br />
The changeover from SPEED to MACH mode is either automatically performed by the FMGEC or<br />
manually by the flight crew (in selected speed target only) by pushing the SPD/MACH pb.<br />
The FMA displays "SPEED" or MACH".<br />
MACH MODE IN CRUISE PHASE (A/THR SOFT MODE)<br />
When the aircraft is in ALT CRZ mode with the autopilot engaged, autothrust engaged in MACH<br />
mode, and is within a ± 3 kt range of the target speed, the autothrust soft mode engages. This<br />
mode reduces the thrust variation in cruise, specifically in light turbulence. The autothrust soft<br />
mode disengages when the speed deviation from the target becomes too large or the target is<br />
modified. Autothrust transition from soft to basic mode may lead to transient thrust variation.<br />
This mode is inhibited with the speedbrakes extended, or with an engine-out, or when Mach<br />
target is below M 0.65.<br />
Applicable to: ALL<br />
GENERAL<br />
SPEED MODE IN APPROACH PHASE<br />
When the aircraft flies an approach in managed speed, the speed target displayed on the PFD in<br />
magenta is variable during the approach.<br />
This managed speed target is computed in the FMGES, using the “ground speed mini” function.<br />
GROUND SPEED MINI FUNCTION PRINCIPLE<br />
The purpose of the ground speed mini function is to take advantage of the aircraft’s inertia when<br />
the wind conditions vary during the approach. It does so by providing the flight crew with an<br />
adequate indicated speed target. When the aircraft flies this indicated speed target, the energy of<br />
RJA A330/A340 FLEET DSC-22_30-90 P 16/22<br />
FCOM ← H to I → 03 MAY 11