ECS Flashcards
How many AMS controllers are installed?
One controller with two channels which control the respective on side system
What does the Air management system (AMS) use bleed air for?
ECS (heating and cooling) Engine start Pressurization Engine and wing anti-ice Water pressure Hot air leak detection
What happens if the channel fails?
The remaining channel is able to control the entire AMS
What provides air for the AMS?
Engine bleeds
APU bleed
External Pneumatic Source
What is bleed air used for?
ECS (heating and cooling)
Engine start
Engine and wing anti-ice
Water pressure
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 faring between the wings
What is the primary use for APU bleed air?
ECS on the ground
Engine starting on the ground
Electrical source (<15,000 ft MSL)
Can engine bleed air flow back to the APU?
No. A check valve prevents flow back
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
What is normal pressure for any engine operation?
45 psi
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
What does the Overheat Detection System (ODS) Observe?
Engine bleeds and packs
APU bleed
Plumbing for the wing and engine anti-ice system
To both loops have to function in order to detect and overheat condition?
Yes, but if one fails the other will work alone to detect the overheat
How many ECS packs are on the airplane? What provides air for the packs?
Two independent packs (left and right)
Each engine provides bleed air to its respective pack
Can a single pack provide adequate temperature control and pressurization?
Yes, up to FL310
Can a single bleed source power both packs?
Yes, through the cross bleed valve
What is the ratio of fresh air to recirculated air?
52% fresh air to 48% recycled air
When are the recirculation fans commanded off?
Cockpit switch
Smoke detected in the recirculated bay
DUMP button is pressed
Respective pack is commanded off
What keeps the three avionic E-BAYs cool?
- FWD & CRT E-BAY Three fans pull air from cabin to bay
* AFT E-BAY Natural air-flow from cabin to bay
When is the Emergency Ram Air Ventilation Activated?
Both packs commanded or failed OFF below 25,000 feet (via left side with electronic control)
Ram air pressure greater than cabin pressure (via right side)
How many channels on the Cabin Pressure Control (CPC)?
2 channels, 1 active and 1 in standby mode
Where does the CPC get Landing Field Elevation (LFE)?
FMS or can be manually selected
What happens when the DUMP button is pressed?
Commands both ECS packs OFF Opens OFV (Outboard Flow Valve) and raises the cabin to 12,400 feet at a rate of 2000 fpm
Can the cabin altitude be raised higher than 12,400 feet?
Yes, by using manual mode
Cabin altitude will rise due to natural leak
In manual mode, will the cabin depressurize on the landing?
No
If engine and APU bleed air are available simultaneously, which has priority?
APU has priority if-
Aircraft is on the ground
Wheel speed <50 KTS
Opposite engine bleed pressure is not enough for engine start
APU you on ground whenever single engine
APU during take off if ECS OFF as long as anti-ice is not on.
When two engines on ground, engine bleeds have priority.
When will the cross bleed 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
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
Thrust levers are set to MAX takeoff
REF A/I sent to ALL on take off
REF ECS set to OFF on MCDU (APU is OFF)
When are ECS packs recovered?
Thrust levers not at MAX, and
Airplane is a 500 AFP with both engines operating
Airplane is greater than 9,700 MSL with 1 engine operating
What happens if smoke is detected in the recirculation day?
Both recirc fans deactivate
Cargo recirc fan deactivates
Cargo outflow valve closes
Where does the CPCS get cruise flight level and landing elevation from?
FMS before take off or CPCS calculates using ambient pressure
LFE may be manually inputted
What color is the LFE on the EICAS?
Green FMS input
Cyan manual input (and single ‘M’ will be in front of LFE)
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 >5000 feet AFE or >10,000 feet MSL
