Operation Manual Part 2

Aerosoft – Digital Aviation
CRJ-70 & CRJ-900
AOM PART 2
Systems Description
VOL
5
5-1-65
26-Jul-2017
INERTIAL REFERENCE SYSTEM
Back in the 1960’s the first inertial reference systems replaced the navigator for trans-oceanic flights. The first
IRS systems used gyros oriented in all three axes. The gyros enable to detect and compute motion the IRS
experiences. Now add a reference / starting point and this enables you to compute the track of an aircraft.
Until today IRS systems were developed further and in conjunction with a GPS system this enables very
accurate computing of the aircrafts position and the flown track as well as attitude changes.
The inertial reference system provides several information to other aircraft systems:
- Attitude
- Heading
- Angular rate
- Linear acceleration
- Present position
The following systems are supplied with those information:
- Flight Control Computers
- Flight Management Computers
- TCAS
- EGPWS
- Fuel system
- Stall protection system
- Flight data recorder
- EFIS
o Attitude Director Indicator, ADI
o Horizontal Situation Indicator, HIS
The IRS normally operates in navigation, NAV, mode. The other available mode, attitude, ATT, mode is used,
when a failure of the unit is detected. As failures of the IRS are not simulated, this mode is not simulated.