737 MAX Flight Crew Operations Manual
Flight Management, Navigation -
Flight Management System
Operation
MN-FLT-OH-201
11.31.23
In the illustration above, the current altitude restriction is deleted and the airplane
continues VNAV climb to the cruise altitude. T/C moves to match the new climb
profile.
The altitude intervention switch may be used to increase cruise altitude. When
level at a cruise altitude, and then cleared to a higher cruise altitude, reset the MCP
altitude to the new cruise altitude and push the altitude intervention switch.
In the illustration above, the cruise altitude is increased and the airplane enters a
VNAV cruise climb at the economy cruise speed.
Altitude Intervention will only apply to the active flight plan.
Altitude Intervention will enabled a climb or descent to a new cruise altitude to
be initiated from the Mode Control Panel.
Altitude Intervention allows the crew to initiate a cruise descent using the altitude
intervention feature on the Mode Control Panel when the airplane is not in close
proximity to the top of descent. A distance of 50 NM is used as a determinant for
this operation. If the airplane is greater than 50 NM from T/D, the pilot may dial
the MCP altitude down and press the ALT INTV button on the MCP. FMC
response is similar to use of Altitude Intervention for a cruise climb initiation.
FMC ALT is set to the new cruise altitude and cruise descent is initiated using
existing guidance techniques for cruise descent. A CRZ DES can be initiated
using altitude intervention when greater than 50 NM from top of descent provided
that the MCP ALT is not set below a descent altitude constraint. For this condition
of more than 50 nm to T/D, and the MCP altitude dialed below a descent
constraint, the result of pressing the ALT INTV button will be to transition from
CRZ to EARLY DES and to honor the constraint. Subsequent presses of the ALT
INTV button may be used to delete the constraint.
FL290
EC
ON
C
RZ
S
PD
FL250
T/C
MCP ALTITUDE RESET AND
ALTITUDE INTERVENTION
SWITCH PUSHED.
March 1, 2021
