DES page
The descent page provides the crew with access to descent planning
The descent page provides the crew with access to descent planning
and inormation. The DES page is selected by pressing the VNAV key
and inormation. The DES page is selected by pressing the VNAV key
on the FMC/MCDU keypad. The NEXT PAGE/PREV PAGE keys may
on the FMC/MCDU keypad. The NEXT PAGE/PREV PAGE keys may
need to be used
need to be used i the aircrat is still at i the aircrat is still at cruise altitude.cruise altitude.
E/D AT:
E/D AT: The End o Descent At inormation displayed in 1L describesThe End o Descent At inormation displayed in 1L describes
the altitude and waypoint at which the descent is planned to end.
the altitude and waypoint at which the descent is planned to end.
Speed Mode:
Speed Mode: Line 2L contains the descent speed mode inormation.Line 2L contains the descent speed mode inormation.
The current descent speed mode is displayed in small ont in the 2L
The current descent speed mode is displayed in small ont in the 2L
header line. The descent speed is
header line. The descent speed is displayed in large ont, in the CAS/ displayed in large ont, in the CAS/
Mach ormat. Descent speed modes
Mach ormat. Descent speed modes available are:available are:
ECON DES: The economy descent mode will yield the lowest aircrat
ECON DES: The economy descent mode will yield the lowest aircrat
operating cost based on the entered cost index. The ECON DES mode
operating cost based on the entered cost index. The ECON DES mode
will attempt to provide an idle thrust descent unless wind conditions
will attempt to provide an idle thrust descent unless wind conditions
encountered during the descent require thrust.
encountered during the descent require thrust.
MCP SPD DES: The MCP selected speed descent mode is a pilot
MCP SPD DES: The MCP selected speed descent mode is a pilot
selected descent speed mode. To initiate this mode, the pilot pushes
selected descent speed mode. To initiate this mode, the pilot pushes
the MCP speed select knob. The speed o the descent can then be
the MCP speed select knob. The speed o the descent can then be
adjusted by selecting the desired speed in the MCP speed
adjusted by selecting the desired speed in the MCP speed selectorselector
window.
LIM SPD DES: The
LIM SPD DES: The limit speed descent mode becomes active in caseslimit speed descent mode becomes active in cases
where the target descent speed exceeds the capabilities o the
where the target descent speed exceeds the capabilities o the
airrame in either the overspeed regime, or the stall buet margin. The
airrame in either the overspeed regime, or the stall buet margin. The
limit speed is own by the vertical guidance unction.
limit speed is own by the vertical guidance unction.
END OF DES: The prompt END OF DES is displayed in the descent
END OF DES: The prompt END OF DES is displayed in the descent
speed mode line when the aircrat has passed the programmed end o
speed mode line when the aircrat has passed the programmed end o
descent constraint waypoint.
descent constraint waypoint.
SPD TRANS:
SPD TRANS: Line 3L displays the speed transition altitude. The lineLine 3L displays the speed transition altitude. The line
contains the transition speed, ollowed by the transition altitude in a
contains the transition speed, ollowed by the transition altitude in a
SSS/AAAAA ormat. This feld may not be updated manually, but it may
SSS/AAAAA ormat. This feld may not be updated manually, but it may
be deleted by pressing the FMC/MCDU DELETE key, then pressing 3L.
be deleted by pressing the FMC/MCDU DELETE key, then pressing 3L.
SPD REST:
SPD REST: Line 4L provides the crew with the ability to enter anLine 4L provides the crew with the ability to enter an
altitude dependent speed restriction. The line contains transition
altitude dependent speed restriction. The line contains transition
speed, ollowed by the transition altitude in a SSS/AAAAA ormat. The
speed, ollowed by the transition altitude in a SSS/AAAAA ormat. The
altitude entry must be an altitude below the cruise altitude, but above
altitude entry must be an altitude below the cruise altitude, but above
the End o Descent altitude.
the End o Descent altitude.
Next Descent Constraint:
Next Descent Constraint: Line 1R contains the descent constraintLine 1R contains the descent constraint
waypoint as defned in the RTE LEGS page o the ight plan. The
waypoint as defned in the RTE LEGS page o the ight plan. The
header line contains ‘AT’ ollowed by the navigation fx identifer to
header line contains ‘AT’ ollowed by the navigation fx identifer to
which the descent constraint is assigned. The constraint is displayed in
which the descent constraint is assigned. The constraint is displayed in
the DES page exactly as it appears in the RTE LEGS page. The
the DES page exactly as it appears in the RTE LEGS page. The descentdescent
constraint cannot be updated or changed rom the DES page, but it
constraint cannot be updated or changed rom the DES page, but it
may be deleted. Deleting the constraint will remove it rom the lateral
may be deleted. Deleting the constraint will remove it rom the lateral
route.
route.
Descend Now Prompt (DES NOW):
Descend Now Prompt (DES NOW): When the aircrat is notWhen the aircrat is not
currently descending, but the MCP altitude selector is set below the
currently descending, but the MCP altitude selector is set below the
current altitude, the DES NOW prompt will be displayed at 6R. The
current altitude, the DES NOW prompt will be displayed at 6R. The
DES NOW> prompt deletes all climb/cruise constraints and commences
DES NOW> prompt deletes all climb/cruise constraints and commences
an early descent. The rate o descent will be approximately 1250 eet
an early descent. The rate o descent will be approximately 1250 eet
per minute until the aircrat intercepts the originally planned vertical
per minute until the aircrat intercepts the originally planned vertical
descent path which would have commenced at the top-o-descent
descent path which would have commenced at the top-o-descent
mark.
Descend Direct Prompt (DES DIR):
Descend Direct Prompt (DES DIR): When the aircrat is descendingWhen the aircrat is descending
and the MCP altitude selector is set below the current aircrat altitude,
and the MCP altitude selector is set below the current aircrat altitude,
the DES DIR> prompt will be displayed. Pressing the associated LSK will
the DES DIR> prompt will be displayed. Pressing the associated LSK will
delete all altitude constraints between the aircrat and the MCP
delete all altitude constraints between the aircrat and the MCP
selected altitude and the FMC will command a descent to reach the
selected altitude and the FMC will command a descent to reach the
MCP altitude. Upon reaching the MCP selected altitude, the vertical
MCP altitude. Upon reaching the MCP selected altitude, the vertical
guidance unction o the FMC will capture the originally computed
guidance unction o the FMC will capture the originally computed
vertical path or the remainder o the descent. Unless deleted or
vertical path or the remainder o the descent. Unless deleted or
modifed, all remaining descent constraints will be adhered to.
modifed, all remaining descent constraints will be adhered to.
Opath Descent Prompt (OFFPATH DES):
Opath Descent Prompt (OFFPATH DES): The opath descent pageThe opath descent page
provides access to “Clean” and speed brake direct descent profles i
provides access to “Clean” and speed brake direct descent profles i
the crew does not wish to use the FMC calculated descent path. This
the crew does not wish to use the FMC calculated descent path. This
page can be access through the <OFFPATH DES prompt in 6L o the
page can be access through the <OFFPATH DES prompt in 6L o the
DES page or DESCENT FORCASTS page.
DES page or DESCENT FORCASTS page.