Operation Manual Part 2

Aerosoft – Digital Aviation
CRJ-70 & CRJ-900
AOM PART 2
Systems Description
VOL
5
5-1-40
26-Jul-2017
The following table shows typical cabin altitude in relation to the aircrafts altitude.
Aircraft altitude (feet)
Cabin altitude (feet)
10‘000
-200
15’000
600
20’000
1’500
25’000
2’700
30’000
4’200
35’000
6’000
41’000
8’000
PRESSURIZATION MODES – AUTOMATIC MODES
Mode
Trigger
Behaviour
Ground mode
A/C on ground
Outflow valve & ground valve → full open
Pre-pressure mode
(Packs ON)
Thrust levers advanced to take-off
Cabin climb rate = 300 ft./min, limited at a
diff. pressure of 150 ft./min
Pre-pressure mode
(Packs OFF)
Thrust levers advanced to take-off
Outflow valve and ground valve closed
Take-off abort
mode
Thrust-levers retarded to idle
Cabin ascends for 20 seconds at approx. 500
ft./Min, then outflow valve full open
Climb mode
Fixed schedule cabin alt. vs. aircraft alt.
Climb rates 500 to 800ft/min dependant on
the aircrafts rate of climb
Flight abort mode
Aircraft maintained altitude 6’000ft
above take-off field elevation for 10
minutes and has initiated descend of
1’000ft/min
System assumes landing elevation
regardless of pre-selected landing elevation
Descent mode
descent
Cabin rate of descent approx. 300 to 700
ft/min to either landing field elevation or
maximum differential.
In case the landing field elevation is higher
than 8’000ft, cabin altitude will be
maintained at maximum differential, until
the airplane descends, then the cabin
altitude will rate up to the pre-selected
landing elevation.
Landing mode
The cabin altitude is driven below field
elevation or the airplane is
unpressurized
When the cabin is below field elevation,
then the cabin is rated up at approximately
600 ft/min for 30 seconds, then the outflow
valve is driven full open
Touch and Go
mode
Landing mode activated and thrust
levers are advanced
System will switch to pre-pressure mode
PRESSURIZATION MODES – MANUAL MODES
Caution: In manual mode, you must manually select HOLD mode as soon as the required altitude is reached
Mode
Trigger
Behaviour
UP
Cabin ascends at selected rate of 150 (±150)
to 3,000 (±500) fpm
DN
Cabin descends at selected rate -100 (±100)
to -2,500 (±500) fpm
HOLD
Disables all previous MAN ALT selections