ECS Flashcards
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
What provides air for the AMS?
Engine bleed
APU bleed
external pneumatic source
What does the AMS provide?
ECS (heating and cooling) Engine start Pressurization Engine and wing anti- ice Water pressure Hot air leak detection
What does the AMS provide?
ECS (heating and cooling) Engine start Pressurization Engine and wing anti-ice Water pressure Hot air leak detection
Can we use APU for wing anti- ice?
No
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
What color is the LFE on the EICAS?
Green FMS input
Cyan. Manual input (an M will be in front of LFE)
Where does the CPCS get cruise flight level and landing elevation from?
FMS before takeoff or CPCS calculates using ambient pressure
LFE may be manually inputed
What happens if smoke is detected in the recirculation bay
Both recirculation fans deactivated
Cargo recirculation fan deactivated
Cargo outflow valve closes
When are ECS packs recovered?
TL not at max, and
Airplane is 500 feet AFE with both engines operating
Airplane is > 9500 MSL with one engine operating
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)
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
If engine and APU bleed air are available simultaneously, which has priority?
APU has priority if
Aircraft is on the ground
Wheelspeed
What is the bleed system priority in flight?
Onside Engine
Opposite side engine
APU (if available)
In manual mode will the cabin de pressurize on landing?
No
Can the cabin altitude be raised higher than 12,400 ft?
Yes, by using manual mode.
Cabin altitude will rise due to natural leak
What happens when the dump button is pressed?
Commands both ECS packs off
Opens OFV and raises the cabin to 12,400 feet at a rate of 2,000 fpm
(Recirculation fans also shut off)
Where does the CPC get landing Field elevation (LFE)?
FMS or can be manually selected
How many channels on the cabin pressure controller (CPC)?
2 channels, one active and one In standby mode
When is the Emergency Ram Air Ventilation activated?
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)
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
When are the recirculation fans commanded off?
Cockpit switch
Smoke detected in the recirculation bay
DUMP button is pressed
Respective pack is commanded off
Can a single bleed source power both packs?
Yes, through the crossbleed valve
Can a single pack provide adequate temperature control and pressurization
Yes, up to FL 310
How many ECS packs are on the airplane? What provides air for the packs?
2 independent packs (left and right)
Each engine provides bleed air to its respective pack
Do both loops have to function in order to detect an overheat condition?
Yes, but if one fails the other will work alone to detect the overheat
What does the Overheat Detection System ODS observe?
Engine bleeds and packs
APU bleed
Plumbing for the wing and engine anti-icing system
What cools the precooler?
Ground. N1 fan
Flight N1 fan or ram air
What is the purpose of the precooler?
Cools the bleed air coming from the engine to the AMS.
What is normal pressure for any engine operation?
45 psi
Where is the bleed air tapped from the engine?
6th and 10th stage compressors (EBV and HSV) respectively
System alternates between valves to regulate an adequate and safe pressure
Can engine bleed air flow back to the APU?
No.
A check valve prevents flow-back
What is the primary use for APU bleed air?
ECS on the ground
Engine starting on the ground
Electrical source (
Where is the external ground source panel located?
Lower fairing between the wings
What is external pneumatic air used for?
ECS on the ground
Engine start on the ground
