Pressurization

Question 1

How is pressurization achieved?

Answer 1

By supplying constant inflow of air and by regulating
amount of air leaving aircraft through Thrust
Recovery Outflow Valve (TROV)
Ref: AOM 2A

Question 2

How is control of Cabin Pressure
Selector page on SMC affected by
pressurization system mode of
operation?

Answer 2

With pressurization system in AUTO mode, cabin
pressure selector page provides a means to view input
data provided by FMS and ADS, and RNG/SET knob
is disabled. With pressurization system in SEMI
mode, data is input via RNG/SET knob for aircraft
cruise/cabin altitude, barometric correction, landing
field elevation, and cabin rate of climb/descent.
Ref: AOM 2A

Question 3

Automatic pressurization is available
down to what source of power?

Answer 3

Main batteries through static inverter
Ref: AOM 2A

Question 4

What’s the meaning of amber
FAULT light on CABIN PRESSURE
CONTROL panel?

Answer 4

It indicates failure of both channels of dual channel
controller: you’d have to select MANUAL
Ref: AOM 2A

Question 5

When does pressurization system
automatically switch to FLIGHT and
begin to pre-pressurize cabin prior to
takeoff?

Answer 5

It’s initiated if doors are closed and any of the
following occur: switch is in FLIGHT position,
airplane begins to move > 9 knots or throttles are
advanced
Ref: AOM 2A

Question 6

What happens in-flight when
LANDING is selected on FLIGHT-

LANDING switch?

Answer 6

Cabin pressure control system automatically switches
to descent pressurization schedule (i.e., 300 fpm).
Ref: AOM 2A

Question 7

When does FLIGHT-LANDING
switch automatically switch to

LANDING?

Answer 7

When aircraft descends from cruise at least 1,000 feet

Will go back to Flight after level flight for 3min at any altitude above FL250
Ref: AOM 2A

Question 8

When would you use semi-automatic
(SEMI) mode?

Answer 8

Whenever FMS data is not available or is invalid,
when directed by checklist, or at discretion of flight
crew (e.g., flying in QFE environment or to high
altitude airport)
Ref: AOM 2A.

Question 9

What’s one of the benefits of flying
in SEMI mode?

Answer 9

You have more control over the system
Ref: AOM 2A

Question 10

What’s the purpose of MANUAL
mode?

Answer 10

Used to manually control TROV and may be used as
backup method in event of failure of both channels of
cabin pressure controller.
Ref: AOM 2A

Question 11

What controls the TROV in manual
mode?

Answer 11

You do using a DC motor
Ref: AOM 2A

Question 12

In manual mode, how would you
determine rate of TROV movement?

Answer 12

By observing motor power indicator: frequency of
flashes is proportional to valve opening or closing
speed.
Ref: AOM 2A

Question 13

What’s the purpose of pressure relief
valve?

Answer 13

It provides rate-limiting function to prevent damage
to aircraft fuselage from excessive positive or
negative pressures.
Ref: AOM 2A

Question 14

What type of action does the system
perform after landing to ensure
minimal differential pressure exists
within the cabin?

Answer 14

During ground operations when TROV is full open,
pressure relief valve is forced open with bleed air
(unless you’re in manual mode)
Ref: AOM 2A

Question 15

When would pressure relief valve
start to relieve pressure?

Answer 15

There are two (2) pneumatic chambers: one relieves
at 10.80 differential pressure and the other relieves at
11.00
Ref: AOM 2A

Question 16

What are cabin pressure low warning
trip points based on?

Answer 16

Landing field elevation
Ref: AOM 2A

Question 17

What are the prerequisites for

Emergency Descent Mode (EDM)?

Answer 17

Cabin Pressure Low CAS message
Aircraft altitude ≥ FL400
Autopilot engaged
Ref: AOM 2A

Question 18

Describe aircraft operation in EDM.

Answer 18

Aircraft automatically enters HDG hold mode, turns
90° left and enters FLCH mode with 340 kt manual
speed (MAN SPD) target. Altitude preselector is set
to 15,000 ft. If not already engaged, AT engages, and
throttles pull back to facilitate rapid descent. The
aircraft performs an ASEL capture at 15,000 ft and
SPD target changes from 340 kts to 250 kts. The
target SPD is maintained as long as AT is engaged.
Ref: AOM 2A

Question 19

How can EDM be cancelled?

Answer 19

AP disconnected

Question 20

With rapid loss of cabin pressure or
altitude, what’s the first thing the
crew should accomplish?

Answer 20

Don personal oxygen mask and ensure mask is set to
100% oxygen
Ref: QRH