Air Management System (AMS)

Question 1

What does the AMS use bleed air for?

Answer 1

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

Question 2

How many AMS controllers are installed?

Answer 2

One controller with 2 channels which control the respective onside system

Question 3

What happens if a channel fails?

Answer 3

The remaining channel is able to control the entire AMS

Question 4

What provides air for the AMS?

Answer 4

Engine bleeds
APU bleed
External Pneumatic Source

Question 5

What is bleed air used for?

Answer 5

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

Question 6

What is external pneumatic air used for?

Answer 6

ECS on the ground
Engine start on the ground

Question 7

Where is the external ground source panel located?

Answer 7

Lower fairing between the wings

Question 8

What is the primary use for APU?

Answer 8

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)

Question 9

Can engine bleed air flow-back to the APU?

Answer 9

No. A check valve prevents flow-back

Question 10

Where is bleed air tapped from the engines?

Answer 10

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

System alternates between valves to regulate an adequate and safe pressure

Question 11

What is normal pressure for any engine operation?

Answer 11

45 psi

Question 12

What is the purpose of the pre-cooler?

Answer 12

Cools the bleed air coming from the engine to the AMS

Question 13

What cools the pre-cooler?

Answer 13

Ground N1 fan
Flight N1 fan or ram air

Question 14

What does the Overheat Detection System (ODS) observe?

Answer 14

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

Question 15

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

Answer 15

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

Question 16

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

Answer 16

2 independent packs (Pack 1 and Pack 2); Each engine provides bleed air to its respective pack

Question 17

Can a single pack provide adequate temperature control and pressurization?

Answer 17

Yes, up to FL310

Question 18

Can a single bleed source power both packs?

Answer 18

Yes, through the crossbleed valve

Question 19

What is the ratio of fresh air to recirculated air?

Answer 19

52% fresh air to 48% recirculated air

Question 20

When are the recirculation fans commanded off?

Answer 20

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

Question 21

What keeps the 3 avionic E-BAYs cool?

Answer 21

FWD & CTR E-BAY 3 fans each pull air from cabin to bay
AFT E-BAY Natural airflow from cabin to bay

Question 22

When is the Emergency Ram Air Ventilation activated?

Answer 22

Both packs commanded or failed OFF below 25,000 ft. MSL
Ram air pressure greater than cabin pressure at any altitude

Question 23

How many channels on the Cabin Pressure Control (CPC)?

Answer 23

2 channels, one active and one in standby mode

Question 24

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

Answer 24

FMS or can be manually selected

Question 25

What happens when the dump button is pressed?

Answer 25

Commands both ECS packs OFF Opens OFV and raises the cabin to 12,400 ft. at a rate of 2,000 fpm Shuts off both recirculating fans

Question 26

Can the cabin altitude be raised higher than 12,400 ft.?

Answer 26

Yes, by using manual mode Cabin altitude will rise due to natural leak

Question 27

In manual mode will the cabin depressurize on landing?

Answer 27

No

Question 28

What is the bleed system priority in flight?

Answer 28

Onside engine Opposite side engine APU (if available)

Question 29

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

Answer 29

APU has priority if Aircraft is on the ground Wheel speed < 50 knots Opposite engine bleed pressure is not enough for engine start

Question 30

When will the crossbleed valve automatically open?

Answer 30

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 31

What are some things that will close the ECS packs?

Answer 31

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)

Question 32

When are ECS packs recovered?

Answer 32

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

Question 33

What happens if smoke is detected in the recirculation bay?

Answer 33

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

Question 34

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

Answer 34

FMS before takeoff or CPCS calculates using ambient pressure; LFE may be manually inputted

Question 35

What color is the LFE on the EICAS?

Answer 35

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

Question 36

What is the ABORT mode?

Answer 36

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