Air Management System

Question 1

AIR MANAGEMENT SYSTEM
Consists of:
A
AIR MANAGEMENT SYSTEM
Consists of:
Pneumatics – the air to be used
Environmental Control System (ECS) – regulates and distributes the air
Pressurization – maintains a safe cabin altitude
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2
Q
What does the AMS use bleed air for?
A
What does the AMS use bleed air for?
1. ECS
2. Engine Start
3. Pressurization
4. Engine and Wing A/I
5. Water Pressure
6. Hot Air Leak Detection
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3
Q
How many AMS controllers are installed?

What happens if a channel fails?
A
How many AMS controllers are installed?
One controller with 2 channels which control the respective onside system

What happens if a channel fails?
The remaining channel is able to control the entire AMS
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4
Q
Pneumatics Gets air from:
A
Pneumatics Gets air from:
Engines
APU
External air source
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5
Q
Where is bleed air tapped from the engines?
A
Where is bleed air tapped from the engines?
6th and 10th stage compressors (EBV and HSV respectively)
System alternates between valves to regulate an adequate and safe pressure
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6
Q
What is normal pressure for any engine operation?
A
What is normal pressure for any engine operation?
45 psi
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7
Q
Engines
A
Engines
Provide bleed air from the 6th (Low) and 10th (High) stages of the compressor
Pre-cooler cools incoming air
Engine bleed used for:
ECS (Environmental Control System)
Anti-ice
Water pressure
Pressurization
Engine start
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8
Q
Can engine bleed air flow-back to the APU?
A
Can engine bleed air flow-back to the APU?
No. A check valve prevents flow-back
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9
Q
What is the primary use for APU bleed air?
A
What is the primary use for APU bleed air?
ECS on the ground
Engine starting on the ground
Electrical source ( < FL330)
Assist with engine start (< FL210)
Bleed source for pressurization, heating, and cooling (< 15,000 ft. MSL)
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10
Q
APU bleed used for:
A
APU bleed used for:
ECS (Environmental Control System)
Water pressure
Pressurization
Engine start
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11
Q
What is the bleed system priority in flight?
Onside engine
Opposite side engine
APU (if available)
A
What is the bleed system priority in flight?
Onside engine
Opposite side engine
APU (if available)
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12
Q
If engine and APU bleed air are available simultaneously, which has priority?
A
If engine and APU bleed air are available simultaneously, which has priority?
APU has priority if
Aircraft is on the ground
Wheel speed < 50 knots
Opposite engine bleed pressure is not enough for engine start
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13
Q
What is the primary use for APU bleed air?
A
What is the primary use for APU bleed air?
* ECS on the ground
* Engine starting on the ground
* Electrical source
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14
Q
When will the crossbleed valve automatically open?
A
When will the crossbleed valve automatically open?
Only one side bleed source is available
Engine 2 start in the air
Engine 1 start in the air if APU is not available
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15
Q
What is external pneumatic air used for?

Where is the external ground source panel located?
A
What is external pneumatic air used for?
ECS on the ground
Engine start on the ground

Where is the external ground source panel located?
Lower fairing between the wings
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16
Q
External Air Sources
A
Air conditioning cart can be used to cool the aircraft’s cabin
High Pressure Air Start cart or air bottle can be used to start an aircraft’s engine
Both packs need to be turned OFF when starting with an external air source to prevent air contamination to the cockpit and cabin.
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17
Q
ENVIRONMENTAL CONTROL SYSTEM (ECS)

Two Packs (one located in each wing to fuselage fairing)
A
ENVIRONMENTAL CONTROL SYSTEM (ECS)
Two Packs (one located in each wing to fuselage fairing)
Engine 1 provides air for pack 1
Engine 2 provides air for pack 2
Incoming air temperature is set via temperature control knobs in the cockpit or the cabin can be controlled by the Flight Attendant via a temperature control knob on the Flight Attendant’s forward galley
control panel.
A single pack can provide air for the entire ECS to a maximum altitude of FL310
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18
Q
How many ECS packs are on the airplane? What provides air for the packs?

Can a single bleed source power both packs?
A
How many ECS packs are on the airplane? What provides air for the packs?
2 independent packs (Pack 1 and Pack 2)
Each engine provides bleed air to its respective pack
Yes, up to FL310

Can a single bleed source power both packs?
Yes, through the crossbleed valve
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19
Q
ENVIRONMENTAL CONTROL SYSTEM (ECS)
Recirc Fans
A
Recirc Fans
Help reduce the load on the packs by recirculating the already-conditioned air and remixing it with incoming cabin/cockpit air
Provide 52% fresh air to 48% recirculated air

Fans will not work when:
The DUMP Button is pressed
When are the recirculation fans commanded off
Cockpit switch
Smoke detected in the recirc bay
DUMP button is pressed
Respective pack is commanded off
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20
Q
What are some things that will close the ECS packs?
A
What are some things that will close the ECS packs?
Any engine start if APU is the bleed source
Engine start on the ground
Respective bleed system duct leak
Bleed air source not available for the pack
TL set to MAX on takeoff
REF A/I set to ALL on takeoff
REF ECS set to OFF on MCDU (APU is OFF)
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21
Q
When are ECS packs recovered?
A
When are ECS packs recovered?

Thrust levers not at Max for all conditions.

TWO ENGINES
the airplane is 500 ft above takeoff field altitude

ONE ENGINE
the airplane is above 9,700 ft during go around
above 9,700 ft, for takeoff fields at 8,000 ft or below
above 15,000 ft, for takeoff fields above 8,000 ft
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22
Q
Gasper Ventilation
A
Gasper Ventilation
Provides personal air to each pilot and passenger positions
Supplied by air from the right recirc fan
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23
Q
At what temp does the Gasper SOV open?
A
At what temp does the Gasper SOV open?
At 35 ̊ C or 95F the Gasper SOV Opens directing Recirc Fan #2
Air directly into Gasper Manifold
Provides personal air to each pilot and passenger
Supplied by air from right record fan
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24
Q
Electronic Compartment Ventilation
What keeps the 3 avionic E-BAYs cool?
A
Electronic Compartment Ventilation
Forward, central, and aft electronic bays are ventilated with conditioned air from the cabin and expelled overboard

What keeps the 3 avionic E-BAYs cool?
FWD & CTR E-BAY 3 fans each pull air from cabin to bay AFT E-BAY Natural air-flow from cabin to bay
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25
Q
Cargo Bays Ventilation
A
Cargo Bays Ventilation
Forward – receives air from the cabin and then vented overboard
Aft – not vented
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26
Q
What happens if smoke is detected in the recirculation bay?
A
What happens if smoke is detected in the recirculation bay?
Both recirculation fans deactivate
Cargo recirculation fan deactivates
Cargo outflow valve closes
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27
Q
Emergency Ram Air Ventilation
A
Emergency Ram Air Ventilation
Allows aircraft ventilation in case of failure of the packs
Emergency ram air enters the left side of the system through a valve if:
In flight, and
Both packs are off/failed,
and below 25,000’

Emergency ram air enters the right side of the system through a check valve that opens when:
Outside pressure > inside pressure
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28
Q
What is the primary purpose for opening the Emer. Ram Air
Ventilation Valve?
A
What is the primary purpose for opening the Emer. Ram Air
Ventilation Valve?
Smoke Evacuation of Flight Deck/Cabin
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29
Q
What does the Overheat Detection System (ODS) observe?
A
What does the Overheat Detection System (ODS) observe?
Engine bleeds and packs
APU bleed
Plumbing for the wing and engine anti-icing system
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30
Q
Do both loops have to function in order to detect on overheat condition?
A
Do both loops have to function in order to detect on overheat condition?
Yes, but if one fails the other will work alone to detect the overheat
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31
Q
Pre-Cooler
What is the purpose of the pre-cooler?

What cools the pre-cooler?
A
Pre-Cooler
What is the purpose of the pre-cooler?
Cools the bleed air coming from the engine to the AMS

What cools the pre-cooler?
Ground N1 fan
Flight N1 fan or ram air
NACA air inlets that provide ram air to cool pre-coolers
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32
Q
PRESSURIZATION
Controlled by:
A
Cabin Pressurization Control System (CPCS)

Cabin Pressurization Controller (CPC)

Negative Pressure Relief Valve - NPRV

Positive Pressure Relief Valve (Safety Valve)

33
Q
When does Cabin Alt Caution come on?
A
When does Cabin Alt Caution come on?
8,000’ Cabin Alt (turns yellow)
Cabin Alt Hi Warning altitude?
9,700’ Cabin Alt (turns red); Aural Warning: CABIN
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34
Q
Cabin Pressurization Controller (CPC)
How many channels on the Cabin Pressure Control (CPC)?
A
Controls OFV
How many channels on the Cabin Pressure Control (CPC)?
2 channels, one active and one in standby mode
Alternate each flight
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35
Q
Where does the CPC get Landing Field Elevation (LFE)?
A
Where does the CPC get Landing Field Elevation (LFE)?
FMS or can be manually selected
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36
Q
Cabin Pressurization Controller (CPC)
A
Regulates amount of air leaving pressure vessel in order to maintain aircraft pressurization
AUTO function – controlled by CPC
MAN function – pilot requests desired position of OFV
LFE – allows manual input of landing field elevation while still operating in the AUTO mode
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37
Q
Negative Pressure Relief Valve - NPRV
A
Negative Pressure Relief Valve - NPRV
Opens automatically when outside (ambient) pressure > cabin pressure  Limitation: -0.5 psi
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38
Q
Positive Pressure Relief Valve – PPRV (Safety Valve)
A
Positive Pressure Relief Valve – PPRV (Safety Valve)
Opens when cabin pressure reaches 8.8 psi (OFV failure) Static Port
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39
Q
Static Port
A
Static Port
Senses and transmits environmental static pressure to the Positive Pressure Relief Valve
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40
Q
Dump Function
What happens when the dump button is pressed?

Can the cabin altitude be raised higher than 12,400 ft.?
A
Dump Function
Only works in AUTO mode
Shuts OFF packs and recirculation fans

What happens when the dump button is pressed?
Commands both ECS packs OFF
Opens OFV and raises the cabin to 12,400 ft. at a rate of 2,000 fpm

Can the cabin altitude be raised higher than 12,400 ft.?
Yes, by using manual mode
Cabin altitude will rise due to natural leak
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41
Q
Where does the CPCS get cruise flight level & landing elevation from?
A
Where does the CPCS get cruise flight level & landing elevation from?
FMS before takeoff or CPCS calculates using ambient pressure
LFE may be manually inputted
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42
Q
What color is the LFE on the EICAS?
A
What color is the LFE on the EICAS?
Green FMS input
Cyan Manual input (an ‘M’ will be in front of LFE)
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43
Q
What is the ABORT mode?
A
What is the ABORT mode?
Cabin is scheduled back to the takeoff altitude if
Airplane stops climbing and begins a descent, and
Airplane has not climbed > 5,000 AFE or > 10,000 MSL
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44
Q
In manual mode will the cabin depressurize on landing?
A
In manual mode will the cabin depressurize on landing?
No
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45
Q
What is normal pressure for any engine operation?
A
What is normal pressure for any engine operation?
45 psi