KLM MD-11 - FMS Coupled Operations; General; FMS Speed Control

MD-11 Flight Crew Operations Manual
k
Automatic Flight -
Description and Operation
Auto.10.16
FMS Coupled Operations
General
The FMS lateral navigation (NAV), vertical profile control (PROF), optimum
speed control, (FMS SPD), and nonprecision approach (NAV and PROF)
functions are coupled to the AP/FD through targets or steering commands.
The FMS also provides AP/FD TO/GA speed references, variable bank angle
limit control, Vmin speed protection, and thrust limiting.
Normally, both FCCs will select the FMC on the same side as the FCC in control.
Both FDs will control to the same steering command.
If the other FCC is selected by pushing the AUTO FLIGHT switch, both FCCs
will select and synchronize to the on-side FMC. The FMA NAV and AP legends
(1 or 2) will show the same side selection.
Failure of the selected FMC while the AFS is coupled will result in a reversion to
the equivalent FCP mode (AFS basic control mode if no equivalent FCP mode
exists). The new FMA mode will flash five times to warn the pilot of the change.
The FCCs then select the functional FMC and the desired FMS mode can be
reengaged by the pilot on the FCP (NAV, PROF, FMS SPD). When the FCCs are
controlling to commands from the on-side FMC, the FCCs do not select the
off-side FMC if the FMC cancels a mode. In this case, only the affected FMS
mode will be cancelled and the AFS will revert to its basic mode. The FMA mode
legend will then flash five times. The pilot must push the AUTO FLIGHT switch
to select the other FMC. The pilot must then reengage the desired FMS mode on
the FCP.
If only one FMC is functional prior to coupling to the AFS, the FCCs will both
select the functional FMC. The FMA NAV and AP legend numbers (1 or 2) will
not be the same if the functional FMC is not on the same side as the selected FCC.
If both FMCs are functioning and in different FMS/AFS control modes (FMC
independent mode operation) when the pilot pushes the AUTO FLIGHT switch,
the FCC will uncouple from the FMS and revert to the basic AFS mode. The FMA
mode legend will flash 5 times. The desired FMS control mode must then be
reengaged by the pilot.
FMS Speed Control
FMS SPD is selected as the AFS reference speed by pushing the FMS SPD switch.
FMS SPD may be engaged independent of PROF engagement. Compatible
control of the AP/FD and ATS modes is computed by the AFS when PROF is not
engaged. FMS SPD switch engagement is cancelled when an FCP speed is
selected.
October 02, 2006