Air Management System Flashcards
Can a single pack provide adequate temperature control and pressurization?
Yes
(up to FL310)
What is the normal pressure for any engine operation?
45 psi
What is the primary use for APU bleed air?
- APU bleed air
- ECS on the ground
- Engine start on the ground
- Electrical source (< FL330)
- Assist with engine start (< FL210)
- Bleed source for pressurization and packs (< 15,000 ft)
Where does the CPC get landing field elevation?
FMS
( can be manually selected )
What happens when the Dump Button is depressed?
Opens the OutFlow Valve
Commands the Packs and Recirc Fans off
A White Bar illuminates on the button
What keeps the 3 avionics E-bays cool?
FWD and CTR:
- 3 fans each pull from cabin to bay
AFT:
- Natural air flow from cabin to bay
Can a single bleed source power both packs?
Yes
( through the crossbleed valve )
In manual mode will the cabin depressurize on landing?
No
What are some conditions 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 source not available for the pack
- Thrust lever set to max on T/O
- REF ECS set to off on MCDU (APU is off)
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 input
What does the overheat detection system (ODS) observe?
Overhead and Leak Detection for:
Engine Bleeds
AC Ducts
APU Bleed Air Distribution
Anti-Ice Supply Ducting
When will the crossbleed valve automatically open?
- Only one side bleed source available
- Engine 2 start in the air
- Engine 1 start in the air IF APU is not available
Where is the bleed air tapped from the engines?
6th and 10th stage (EBV and HSV respectively)
System alternates between valves to regulate an adequate and safe pressure
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 AFE or > 10000 MSL
What provides air for the AMS?
- Engine bleeds
- APU bleed
- External pneumatic source
When are ECS packs recovered?
Can engine bleed air flow back to the APU?
No
(check valve prevents flowback)
How many AMS controllers are there?
One controller with 2 channels which
control their respective onside system
What color is the LFE on the EICAS?
- Green FMS input
- Cyan manual input (an “M” will be in front of LFE)
How many channels on the cabin pressure control (CPC)?
2
( one active and one in standby mode )
What happens when the dump button is pressed?
- Commands both ECS packs off
- Opens OFV and raises cabin to 12400ft at 2000fpm
When are the recirc fans commanded off?
- Cockpit switch
- Smoke detected in the recirc bay
- DUMP button is pressed
- Respective pack is commanded off
What is the bleed system priority in flight?
- Onside engine
- Offside engine
- APU
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)
When is the emergency ram air ventilation activated?
- Both packs commanded off or failed < FL250 (left side electronically controlled)
- Ram Air pressure greater than cabin pressure (right side)
Do both loops have to function in order to detect an overheat condition?
No. Though Dual Loop is Normal. But if a single loop fails the remaining monitors the system
What is the ratio of fresh air to recycled air?
52% fresh
48% recycled
What happens if smoke is detected in the recirculation bay?
What is bleed air used for?
- ECS heating and cooling
- Engine start
- Engine and wing A/I
- Water pressurization
Where is the external ground source panel located?
Lower fairing between the wings
What cools the pre-cooler?
What is the AMS used for?
- ECS ( Heating and Cooling)
- Engine start
- Pressurization
- Engine and wing A/I
- Water pressure
- Hot air leak detection
Can the altitude be raised higher than 12400ft?
Yes
( Using manual mode, cabin altitude will rise due to a natural leak )
What is the purpose of the precooler?
Cools the bleed air supplied to the AMS
Which bleed source, Engine or APU, has priority?
The APU has priority IF:
- Aircraft is on ground
- Wheel speed <50 kts
( Offside engine bleed psiis not enough for engine start)
What happens if a channel fails?
The remaining channel is able to control the entire AMS
