Embraer EMB145 Operation Manual page 2624

AUTOPILOT
TURN KNOB SUBMODE
The Turn Knob submode allows the pilot to generate a roll attitude
command manually with the Turn Control Knob. Moving the Turn
Control Knob out of detent, with the autopilot engaged, cancels all
other lateral modes including Heading Hold mode in both Flight
Directors.
When the Turn Control Knob is out of detent, the autopilot will maintain
a roll attitude proportional to the displacement of the knob. The
autopilot will revert back to Heading Hold mode when the turn knob is
placed in the detent position. Turn Knob submode is annunciated on
the PFD by the ROL green label when out of detent and the autopilot
is engaged. When the autopilot is disengaged and the Turn Control
Knob is out of detent, the TKNB label is displayed in the PFD and the
autopilot engagement is inhibited.
WINGS LEVEL SUBMODE (Airplanes equipped with EICAS 16 and
on)
The Wings Level submode provides a roll command of 0º. This mode
is active in the Go Around mode, Windshear mode or if the primary
heading data is invalid. Therefore, this mode is available even if either
attitude source is invalid. This mode is annunciated on the PFD by the
ROL green label.
HEADING SELECT MODE (HDG)
The HDG mode is selected by pressing the HDG button on the flight
guidance controller or by arming LOC, VOR, VAPP, or BC. This mode
allows the Flight Director to track the EHSI heading bug, as set by the
heading select knob. The Heading Select mode is annunciated on the
PFD by the green HDG label.
The mode will be inhibited by the following conditions:
Turn Control Knob out of detent with autopilot engaged.
Displayed heading invalid.
Page
2-19-10 2
AIRPLANE
OPERATIONS
MANUAL
Code
01 REVISION 36