Air Management System Flashcards
(55 cards)
The Air Management System (AMS) consists of:
- pneumatic system
- environmental control system (ECS)
What does the AMS controller do?
provides primary control for various airplane subsystems such as
- bleed control
- environmental control
- hot air leak detection
- crew oxygen monitoring
- wing ice protection
- engine anti-ice
How many channels does the AMS controller have?
two; control the respective onside system; in case of failure one controller is capable of controlling entire system
PACK (1 or 2) button PUSH IN
allows automatic operation by the AMS; system logic opens pack 1 or 2 flow control valve
PACK (1 or 2) button PUSH OUT
manually closes the pack 1 or 2 flow control valve
RECIRC FAN button PUSH IN
allows automatic operation by the AMS; system logic turns on both recirc fans
RECIRC FAN button PUSH OUT
turns off both recirculation fans
XBLEED button PUSH IN
allows automatic operation by the AMS
XBLEED button PUSH OUT
manually closes the crossbleed
BLEED 1/2 button PUSH IN
allows automatic operation by the AMS;
BLEED 1/2 button PUSH OUT
manually closes engine blead; when a leak is detected, and amber light illuminates on the top half of the button
APU BLEED button PUSH IN
allows automatic operation by the AMS
APU BLEED button PUSH OUT
closes the APU bleed valve; when a leak is detected, an amber light illuminates on the top half of the button
DUMP button
provides rapid cabin depressurization by opening the outflow valve and commanding the packs and the recirculation fan off
Bleed air is used by:
- environmental control system (ECS)
- engine start
- engine and wing anti-ice
- water pressurization
How is bleed source automatically controlled
via opening/closing of the Low Pressure Check Valve and of the High Stage Bleed Valve located in the nacelle
How is engine bleed air temperature regulated
by a precooler which uses the engine fan air modulated by the Fan Air Valve (FAMV)
The Engine Bleed Valve is commanded open when the following conditions occur simultaneously:
- respective bleed switch set to AUTO
- respective engine bleed is available
- no fire is detected in the respective engine
- no bleed duct leak is detected
When does the bleed system automatically shut down
when a leak, overpressure or fail condition is identified
The APU Bleed Valve (ABV) is commanded open when the following conditions occur simultaneously:
- APU switch is set to AUTO
- APU bleed is available
- No APU and left bleed duct leak
- left engine bleed is unavailable
- anti-ice system not requested
The cross bleed is commanded open when the XBLEED button is pushed in (AUTO) and any of the following conditions are met:
- one side provides manifold pressure and there is not a bleed air source on the opposite side
- APU bleed button pushed out for main engine start
- engine #2 start in the air
- APU bleed OFF for engine #1 start in the air
- no bleed leak, unless starting the engine
When will the engine bleed #1 be commanded closed
if the cross bleed fails OPEN and the other bleed source is the #2 engine
Describe the Overheat Detection System
comprised of overheat sensors and electronic controls; six zones of dual loop overheat sensors; both loops must detect overheat or leak unless one has failed
The recirculation fans are commanded off when:
- the DUMP button is pressed
- smoke is detected in the recirc bay
- both packs are commanded OFF
- on ground cabin warm-up mode when the APU is the bleed source
- the cargo bay fire signal activates
