PRIMUS
r
1000 Integrated Avionics System
A28--1146--112--00
2-5
System Description
PFD formats are selected using the DC. MFD navigation and aircraft
performance displays are selected using the MFD mounted bezel
controllers. If an FMS is installed, the remote--mounted MFD joystick
menu is used for waypoint designation. The guidance controller contains
the course, heading, selected speed, and altitude preselect controls.
Each symbol generator (SG) can drive all five displays. When a PFD
or EICAS display fails, the on--side reversionary control panel is used
to replace the onside MFD with either a PFD or EICAS display.
The display dual processor symbol generator in the IAC functions as
the data processor for the display system. It receives digital and
discrete inputs, organizes the information into the correct formats as
defined by the DC, and transmits these formats to the display units.
When the display system is in its normal (no failure) configuration, IAC No.
1 drives the pilot’s PFD, MFD and the EICAS. IAC No. 2 drives the copilot’s
PFD and the MFD display. Wraparound signals are used for critical
parameters (such as pitch or roll data) to ensure information accuracy.
The dual channel DAUs transmit all the aircraft engine information to the
symbol generator for display on the EICAS display. They also transmit
analog data for display of some aircraft subsystem information. DAU 1
inputs left engine data and DAU 2 inputs right engine data.
AIR DATA SYSTEM (ADS)
The ADS includes dual micro air data computers (MADC). The aircraft’s
air data system also includes standby airspeed and altimeter indicators
that are driven directly from the aircraft pitot--static system.
The MADC is a microprocessor based digital computer that performs
digital computations, and supplies digital outputs. The MADC receives
pitot--static pressures and total air temperature inputs for computing the
standard air data functions. The MADC outputs, drives the altimeter
and Mach/airspeed displays, transponder, flight recorder, flight director,
and autopilot, as well as other elements of the flight control system. The
guidance controller is used to select the desired altitude reference for
the altitude alerting and altitude preselect functions. The computations
for each of these functions is performed by the IAC’s flight director
computer.
