Air Management System Flashcards
(B) What does the AMS use bleed air for?
- Environmental Control System (H/C)
- Engine Start
- Pressurization
- Engine and wing anti-ice
- Hot air leak detection
(B) How many AMS controllers are installed?
One controller with 2 channels which control the respective onside system
(B) What happens if a channel fails?
The remaining channel is able to control the entire system
(B) What provides air for the AMS?
- Engine bleeds
- APU bleeds
- External pneumatic source
(B) What is bleed air used for?
- ECS for heating and cooling
- Engine start
- Engine and wing-anti ice
- Water pressurization
(B) What is external pneumatic air used for?
ECS on the ground
Engine start on the ground
(B) Where is the external ground source panel located?
Lower fairing in between the wings
(B) What is the primary use for APU bleed air?
- ECS on the Ground
- Engine starting on the ground
- Electrical source up to FL330
- Assist in engine start up to FL210
- Bleed source for pressurization, heating and cooling up to 15,000ft. MSL
(B) Can engine bleed air flow back to the APU
No. There is an associated check valve which does not allow air to flow into APU
(B) Where is the bleed air tapped from the engines?
6th and 10th stage of the compressor (EBV and HSV respectively)
System alternates between valves to regulate an adequate and safe pressure
(B) What is the normal pressure for any engine operation?
45 PSI
(B) What is the purpose of the pre-cooler?
Cools the bleed air coming from the engine to the AMS
(B) What cools the pre-cooler?
- Ground N1 Fan
2. Flight N1 Fan or ram air
(B) What does the overheat detection system (ODS) observe?
- Engine bleeds and packs
- APU bleed
- Plumbing for the wing and engine anti-icing system
(B) Do both loops have to function in order to detect on overheat conditions?
Yes - but if one fails the other will work alone to detect the overheat
(B) How many ECS packs are on the airplane? What provides air for the packs?
- 2 Independent packs
- Each engine provides bleed air to it’s respective pack
- APU on ground or up to 15,000ft. MSL
(B) Can a single pack provide adequate temperature control and pressurization?
Yes, up to FL310
(B) Can a single bleed source power both packs?
Yes, through the cross-bleed valve in the AUTO light off position
(B) What is the ratio of fresh and recirculated air?
52% Fresh Air/48% Recirculated Air
(B) When are the recirculation fans commanded off?
- Cockpit switch pushed out and illuminated
- Smoke detected in the recirculation bay
- Dump Valve is pressed
- Respective pack is commanded off
(B) What keeps the 3 avionics E-Bay’s cool?
FWD and CTR E-Bay - 3 Fans each pull air from cabin to bay
AFT E-Bay - Natural air-flow from cabin to bay
(B) 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 the cabin pressure (via right side as a check valve)
(B) How many channels on the Cabin Pressure Control (CPC) are there?
2 - Channels, one active and one standby mode
(B) Where does the CPC get Landing Field Elevation (LFE)?
FMS or can be manually selected
(B) What happens when the dump button is pressed?
- Commands both ECS packs OFF
- Turns OFF recirculation fans
- Opens OFV and raises the cabin to 12,400 ft at a rate of 2,000 fpm
(B) Can the cabin altitude be raised higher than 12,400 feet?
- Yes, by using manual mode
- Cabin altitude will rise due to natural leak
(B) In manual mode will the cabin pressure depressurize on landing?
No
(B) What is the bleed system priority in flight
- Onside Engine
- Opposite Engine
- APU (if available)
(B) If engine and APU bleed air are available simultaneously, which has priority?
APU has priority if:
- Aircraft is on the ground (Unless > 50 knots and right engine is used only)
- Wheel speed less than 50 knots
- Opposite engine bleed pressure is not enough for engine start
(B) 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
(B) 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 is OFF)
(B) When are the ECS packs recovered?
TL not at MAX
Airplane is 500ft. AFE with both engines operating
Airplane is greater than 9,700 MSL with one engine operating
(B) What happens if smoke is detected in the recirculation bay?
- Both recirculation fans deactivate
- Cargo recirculation fans deactivate
- Cargo outflow valve closes
(B) 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 inputted
(B) What color is the LFE on the EICAS?
- Green FMS input
- Cyan Manual input (an ‘M’ will be in front of LFE)
(B) What is the ABORT mode?
- Cabin is scheduled back to the takeoff altitude if:
- Airplane stops climbing and begins a descent
- Airplane has not climbed greater than 5,000 AFE or 10,000 MSL
