PRIMUS
r
1000 Integrated Avionics System
A28--1146--112--00
8-3
Modes of Operation
HEADING SELECT MODE
The heading select mode is used to maintain a magnetic heading. The
desired heading is set using the HDG knob on the guidance controller
(GC). The mode is selected with the HDG button on the GC and is
annunciated on the HDG button and also by a green HDG on the top
left side of the PFD. In the HDG mode, the integrated avionics computer
(IAC) uses the command bars to indicate a turn to the heading selected
with the heading bug on the horizontal situation indicator (HSI). The
heading select signal is gain programmed as a function of airspeed.
Selecting low bank (BNK) on the GC limits bank angles to 14
_
.
When turning the heading bug greater than 180
°
, the aircraft continues
to turn in the same direction as the bug was originally moving.
Therefore, if the bug is turned to the right 270
°
, the aircraft turns to the
right in a 270
°
turn instead of turning left 90
°
.
The the heading select mode is cancelled by any one of the following
actions:
D
Capture of any other lateral steering mode
D
Selection of symbol generator (SG) reversionary mode
D
Selection of go--around (GA)
D
Placing TURN knob out of detent with autopilot engaged
D
Selection of attitude and heading reference system (AHRS)
reversionary mode
D
Pushing the couple (CPL) button on the GC
D
Pushing the heading (HDG) button.
NOTES:
1. Above 25,000 feet mean sea level (MSL), the bank
angle in heading select mode is automatically reduced
to 14
_
. When descending below 24,750 MSL, the bank
angle is returned to the standard bank value of 27
_
.
2. Each of the flight director modes can be cancelled by
a variety of pilot (or systems) options. Only the most
typical methods are shown here, and for each flight
director mode in this section.