190-00709-05 Rev. D
Garmin G1000 Pilot’s Guide for the Socata TBM 850/900
517
AUTOMATIC FLIGHT CONTROL SYSTEM
a
UtOmatic
R
eveRsiOn
tO
P
itch
h
OlD
m
ODe
Several situations can occur while Vertical Path Tracking Mode is active which cause the flight director to
revert to Pitch Hold Mode:
• Vertical deviation exceeds 200 feet during an overspeed condition.
• Vertical deviation experiences a discontinuity that both exceeds 200 feet in magnitude and results in the
vertical deviation exceeding 200 feet in magnitude. Such discontinuities are usually caused by flight plan
changes that affect the vertical profile.
• Vertical deviation becomes invalid (the Vertical Deviation Indicator is removed from the PFD).
• A display enters Reversionary Mode (this does not apply to an active vertical direct-to).
Unless VNV is disabled, Vertical Path Tracking Mode and the appropriate altitude capture mode become
armed following the reversion to Pitch Hold Mode to allow for possible profile recapture.
n
On
-P
ath
D
escents
Pitch Hold, Vertical Speed, and Flight Level Change modes can also be used to fly non-path descents
while VNV flight control is selected. If the
VS
or
FLC
Key is pressed while Vertical Path Tracking Mode is
selected, Vertical Path Tracking Mode reverts to armed along with the appropriate altitude capture mode to
allow profile re-capture.
Figure 7-15 Flight Level Change VNV Non-Path Descent
To prevent immediate profile re-capture, the following must be satisfied:
• At least 10 seconds have passed since the non-path transition was initiated
• Vertical deviation from the profile has exceeded 250 feet, but is now less than 200 feet
Pressing the
VNV
Key twice re-arms Vertical Path Tracking for immediate profile re-capture.
VNV TARGET ALTITUDE CAPTURE MODE (ALTV)
NOTE:
Armed VNV Target Altitude and Selected Altitude capture modes are mutually exclusive. However,
Selected Altitude Capture Mode is armed implicitly (not annunciated) whenever VNV Target Altitude Capture
Mode is armed.
VNV Target Altitude Capture is analogous to Selected Altitude Capture Mode and is armed automatically
after the
VNV
Key is pressed and the next VNV Target Altitude is to be intercepted before the Selected
Altitude. The annunciation ‘ALTV’ indicates that the VNV Target Altitude is to be captured. VNV Target
Altitudes are shown in the active flight plan or vertical direct-to, and can be entered manually or loaded
from a database (see the Flight Management Section for details). At the same time as “TOD within 1 minute”
is annunciated in the Navigation Status Box, the active VNV Target Altitude is displayed above the Vertical
Speed Indicator (see Figure 7-13).
NOTE:
When the Selected Altitude is set to the VNV Target Altitude, Selected Altitude Capture Mode (ALTS)
will be armed even though the altitude value is part of the active VNAV flight plan.
