Air Management System

Question 1

How many AMS controllers are installed?

Answer 1

One controller with 2 channels which control the respective onside system

Question 2

What happens if a channel fails?

Answer 2

The remaining channel is able to control the entire AMS

Question 3

What provides air for the AMS?

Answer 3

Engine bleeds
APU bleed
External pneumatic source

Question 4

What is bleed air used for?

Answer 4

ECS (heating & cooling)
Engine start
Engine and wing anti-ice
Water pressurization

Question 5

Where is the external ground source panel located?

Answer 5

Lower fairing between the wings

Question 6

What is external pneumatic air used for?

Answer 6

ECS on the ground

Engine start on the ground

Question 7

What is the primary use for APU bleed air?

Answer 7

ECS on the ground
Engine starting on the ground
Assist with engine start
Bleed source for pressurization, heating, and cooling

Question 8

Can engine bleed air flow-back to the APU?

Answer 8

No, a check valve prevents flow-back

Question 9

Where is bleed air tapped from the engines?

Answer 9

6th and 10th stage compression (EBV and HSV respectively)

System alternates between valves to regulate an adequate and safe pressure

Question 10

What is normal pressure for any engine operation?

Answer 10

45 psi

Question 11

What is the purpose of the pre-cooler?

Answer 11

Cools the bleed air coming from the engine to the AMS

Question 12

What cools the pre-cooler?

Answer 12

Ground: N1 fan
Flight: N1 fan or ram air

Question 13

What does the overheat detection system (ODS) observe? (What systems)

Answer 13

Engine bleed and packs
APU bleed
Plumbing for the wing and engine anti-icing system

Question 14

Do both loops have to function in order to detect on overheat condition?

Answer 14

Yes, but if one fails the other will work alone to detect the overheat

Question 15

How many ECS packs are on the airplane? What provides air for the packs?

Answer 15

2 independent packs (left and right)

Each engine provides bleed air to its respective pack

Question 16

Can a single pack provide adequate temperature control and pressurization?

Answer 16

Yes, up to FL310

Question 17

Can a single bleed source power both packs?

Answer 17

Yes, through the crossbleed valve

Question 18

What is the ratio of fresh air to recirculated air?

Answer 18

52% fresh to 48% recirculated air

Question 19

When are the recirculating fans commanded off?

Answer 19

Cockpit switch
Smoke detected in the recirc bay
DUMP button is pressed
Respective pack is commanded off

Question 20

What keeps the 3 avionics E-bays cool

Answer 20

Fwd & CTR E-BAY………3 fans each pull air from the cabin to the bay
AFT E-BAY…… Natural air-flow from cabin to bay

Question 21

When is the emergency ram ventilation activated?

Answer 21

Both packs commanded or failed OFF below 25,000 ft (via left side and electronically controlled)

Ram air pressure greater than cabin pressure (via right side)

Question 22

How many channels on the Cabin Pressure Control (CPC)

Answer 22

2 channels, one active and one in standby mode

Question 23

Where does the CPC get Landing Field Elevation (LFE) ?

Answer 23

FMS or can be manually set by pilot

Question 24

What happens when the dump button is pressed?

Answer 24

Commands both ECS packs OFF

Opens OFV and raises the cabin to 12,400 ft at a rate of 2000 fpm

Question 25

Can cabin altitude be raised higher than 12,400?

Answer 25

Yes, by using manual mode

Cabin altitude will raise due to natural leak

Question 26

In manual mode will the cabin depressurize on landing?

Answer 26

No

Question 27

What is the bleed system priority in flight?

Answer 27

Onside engine
Opposite side engine
APU (if available)

Question 28

If engine and APU bleed air are available simultaneously, which has priority?

Answer 28

APU has priority if
Aircraft is on the ground
Wheel speed greater than 50 kts
Opposite engine bleed pressure is not is not enough for engine start.

Question 29

When will cross bleed valve automatically open?

Answer 29

Only one side bleed source is available
Engine 2 start in the air
Engine 1 start in the air if APU is not available

Question 30

What are some things that will close the ECS packs?

Answer 30

Any engine start if APU is the bleed source
Engine start on the ground
Respective bleed system duct leak
Bleed 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)

Question 31

When are ECS packs recovered?

Answer 31

TL not at MAX and;
Airplane is 500 AFE with both engines operating
Airplane is > 9,700 MSL with one engine operating

Question 32

What happens if smoke is detected in the recirculation bay?

Answer 32

Both recirc fans deactivate
Cargo recirc fan deactivates
Cargo outflow valve closes

Question 33

Where does the CPCS get cruise flight level & landing elevation from?

Answer 33

FMS before takeoff or CPCS calculates using ambient pressure

LFE may be manually inputted

Question 34

What color is the LFE on the EICAS?

Answer 34

Green: FMS input
Cyan: Manual input (an M will be in front of LFE )

Question 35

What is the ABORT mode?

Answer 35

Cabin is scheduled back to the takeoff altitude if;
Airplane stops climbing and begins a descent, and
Airplane has not climbed > 5000 AFE or > 10,000 MSL

Question 36

What does the AMS use bleed air for?

Answer 36

ECS (heating&cooling)
Engine start
Pressurization 
Engine and wing anti-ice
Water pressure
Hot air leak detection