PRIMUS
r
1000 Integrated Avionics System
A28--1146--112--00
System Description
2-2
EFIS annunciators indicate the selected autopilot/flight director mode,
altitude alert, radio altitude (RA) reference and go--around mode
engagement. Pitch and roll steering commands, calculated by the IAC
flight director function in conjunction with the guidance controller, are
displayed by command bars that direct the pilot to reach and/or
maintain the required flightpath or altitude.
The IAC is the focal point of information flow in this system. It converts
input data and information to the pilot--selected formats and displays
them on the attitude director indicator (ADI) and the horizontal situation
indicator (HSI) on the primary flight display (PFD). The IAC generates
information for display on the multifunction display (MFD). It also
computes the necessary flight director command bar steering
information for the autopilot function. The IAC also collects information
for the EICAS displays.
The two IACs are interconnected with high level data link control
(HDLC) lines. This and other interconnects allow the flight guidance and
symbol generators to share, compare, and communicate information.
The PRIMUS
â
II Radio System is connected to the FGS by the radio
system bus (RSB).
When engaged and coupled to the flight director commands, the
PRIMUS
â
1000 IACs control the aircraft using the same commands
that are displayed on the ADI. When the autopilot is engaged and
uncoupled from the flight director commands, manual pitch commands
can be entered using the touch control steering (TCS) button or the
autopilot PITCH wheel.
The TCAS receives air data information from the ADS by way of the
diversity transponder. Heading data is supplied by the appropriate
AHRS. TCAS supplies the electronic display system with selected
aircraft traffic and conflict avoidance information.
The IAC has built--in multilevel test capability. The self--test includes an
automatic power--up self--check and initiated testing. It also includes
and on--ground maintenance test and fault storage. Refer to Section 9,
Troubleshooting, for pilot--initiated test information.