Avidyne IFD440 - Direct-To

IFD400 Series Pilot Guide
2-16 FMS Subsystem
Altitude Constraint Types
Cross
Kind
Altitude
Numeric field
representing the
distance prior to the
waypoint that the
constraint is to be
achieved
At Or Below
At
At or Above
Between
(“window”)
Numeric field
representing the
target altitude.
Minimum allowable
value is 100 feet.
Window constraints
have an upper and
lower altitude field.
Altitude Constraint Fields
The default value for the crossing distance is 5.0nm for airports
and 0.0nm for all other waypoints.
The only waypoints that do not permit altitude constraints are:
 Origin
 Destination, if it has an approach selected
 Missed Approach Point
 Altitude Terminated Legs
Altitude constraints are used to drive enroute VNAV functions
(see page 5-34).
DIRECT-TO
"Direct To" clearances are sometimes issued to waypoints that
are not currently in the flight plan, but often are issued as
shortcuts to waypoints that have already been planned. The FMS
seamlessly handles both of those situations using the Direct-To
key to perform either an "offpath direct-to" or an "onpath direct-