Vertical Navigation Function (cont.)
To activate the VNAV function:
1. Review the calculated vertical speed. If the calculated
speed does not fit within the performance guidelines of
your aircraft, manually enter the appropriate speed in
the ‘At’ field and press
E
.
2. Highlight the ‘Vnav’ field and press
E
.
3. Select the ’On’ setting and press
E
.
The VNAV status at the bottom of the page will
change from ‘Enter Profile’ to ‘Begin In _____’, indicating
the time remaining to begin the descent. Once you are
less than 15 seconds from the starting point of the
descent, you’ll be informed with a ‘Start Altitude Change’
message.
If the maneuver has already started, the status field
will display a ‘Navigating’ status. While the VNAV func-
tion is active, the vertical navigation page will provide a
continuous display of the recommended altitude you
should be at (the ‘From’ field) and the vertical speed
required (the ‘At’ field) to complete the maneuver. The
recommended altitude during any active VNAV maneu-
ver is also displayed at the bottom right of the navigation
page.
When the recommended altitude is within 1,000 feet
of the final altitude, you’ll be informed with a ‘Final
Altitude Alert’ message.
The VNAV function will be cancelled automatically if
the active route or GOTO is changed in any way (e.g.,
performing an on-route GOTO or adding a waypoint to a
route). Whenever this happens, you’ll be informed with a
‘VNAV Cancelled’ message.
If your current speed does not exceed 35 knots, or a
route waypoint that has already been passed is selected,
the status line will display ‘Invalid Profile’. If there is no
active GOTO or route, the status field will display ‘No
Active Waypoint’.
While on an active GOTO
or route, you may create a
vertical decent profile by
using the VNAV function.
Once the VNAV function
has been initiated and
you’ve reached your descent
point, a ‘Navigating’ status
will appear at the bottom of
the page.
Main Menu:
E6-B
Reference
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92 manual 4/15/98 3:48 PM Page 65
