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Flight Management System (FMS) for the Agusta AW139/AB139 Helicopter
When the aircraft descends below the cruise altitude, the speed
D
command changes to the descent speed schedule and the descent
CAS/MACH target is displayed. The descent speed command is
used during any intermediate leveloffs. When the aircraft nears the
speed/altitude limit, the speed command anticipates the speed limit
and slows the aircraft prior to reaching the altitude.
Nearing the destination, the speed command changes to the
D
approach speed schedule defined during initialization. The default
values for the transition to approach speed are 15 flight plan miles
from the destination or 5 miles from the first approach waypoint.
Lowering the landing gear or flaps also changes the speed
command to the approach speed schedule. For some aircraft
installations, an approach speed command is permitted for each flap
setting.
NOTE:
When a climb is performed inside the approach area (as
defined from the INIT DIST on the APPROACH SPEED
page), the approach speed target transitions to climb and
then cruise or descent as appropriate. To reinstate the
approach speed target, the pilot must reenter the INIT
DIST on the APPROACH SPEED page.
In the event the flight director transitions to go--around, the speed
D
command changes to the go--around speed schedule defined during
initialization. For some aircraft installations, a go--around speed
command is permitted for each flap setting. When the go--around
speed command is active, modification of the active flight plan or
selection of a new approach results in the FMS transitioning from
go--around to the approach speed schedule. When the active flight
plan destination is changed while the go--around speed schedule is
active, the speed command transitions from go--around to climb
speed schedule.
Waypoint Speed Constraint
The FMS has the ability to cross a waypoint at a specified speed. This
is referred to as a waypoint speed constraint. A waypoint speed
constraint is retrieved with a procedure (SID/STAR/approach) or
entered by the pilot.
Waypoint speed constraints are treated differently by the FMS
depending on the phase of flight. Waypoint speed constraints in the
climb phase of flight results in the FMS applying the speed constraint
to all legs prior to the waypoint. The climb phase of flight is defined as
the legs of the flight plan prior to the TOC. On sequencing the waypoint,
the FMS attempts to return to the automatic speed schedules when no
other waypoint speed constraint exists.
A28- - 1146- - 181
REV 3 Mar 2009
Honeywell International Inc. Do not copy without express permission of Honeywell.
Flight Plan
7-51
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