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
