Air Management System Flashcards
What are the Systems associated with the Air Management System (AMS)
Pneumatic System
Environmental Control System (ECS)
Cabin Pressure Control System (CPCS)
What is different about the CPCS (Cabin Pressure Control System)?
It has a separate controller
How many Channels does the AMS have?
2
What is the pneumatic system used for?
ECS
Engine Start
Engine and Wing Anti-Ice
Water Pressurisation
Where does the Pneumatic System get its Bleed Air?
Engines or APU
When is the Engine Bleed Valve opened?
Respective Bleed Switch AUTO
Respective Engine Bleed Available
No Fire detected
No Bleed Duct Leak
What does the ECS provide?
Pressurised & Conditioned air for the Flight Deck & Cabin
Filtered Cabin Air Recirculation
Air Supply for the Gaspers
Fan Air Cooling for Avionics
Emergency RAM Air Ventilation for Flight Deck Smoke Clearance
Cargo Bay Ventilation
When will the Gasper Shutoff Valve automatically OPEN?
When the Temperature of the Gasper Air Supply is 35°C +
What Supplies Air to the Gasper Ventilation System?
RIGHT recirculation fan
How many Ventilation fans are in the FWD, Centre & AFT Electronics Bay?
3, 3, NONE
Where do the ventilation fans draw their air from and to for the FWD Electronic Bay?
Cockpit > Underfloor Recirculation Bay
Where do the ventilation fans draw their air from and to for the Centre Electronic Bay?
Rear Cabin > Underfloor Recirculation Bay
How many ventilation fans are in the AFT Electronics Bay?
0
Why is the Forward Cargo Bay Ventilated? (NOT applicable at BACF)
To provide ventilation for live animals
Where are the Emergency RAM Air Valves located?
Pack 1 - Emergency RAM Air Valve
Pack 2 - Emergency RAM Air CHECK Valve
What is the purpose of RAM Air Ventilation?
To provide for smoke removal from the flight deck
OR
In the event of PACK Shutdown
When is the Emergency RAM Air Valve commanded OPEN?
Both Packs OFF
Both Packs FAIL
Altitude less than 25,000ft
What is the difference between the Emergency RAM Air Valve and the Emergency RAM Air CHECK Valve?
The Check valve does not require electronic control, and is commanded OPEN whenever the RAM air circuit is a greater pressure than the cabin
What are RAIDS?
RAM Air Inlet Doors, that modulate and optimise the quantity of RAM air sent to the packs via changes in their deflection
How many RAIDs are there?
2
How can the CPCS be operated and what is normal operation?
AUTOMATIC - Normal
MANUAL
What does the CPCS do?
Controls the Cabin Altitude, differential Pressure and Cabin Altitude Rate of Change
What is the nominal differential pressure below 37,000ft?
7.8psi
What is the max differential pressure?
8.4psi
How is the CPCS controlled manually?
Pilot must open or close the OUTFLOW Valve to maintain the desired Cabin Altitude, and there is no automatic cabin depressurisation on the ground after landing
When may a PACK be OFF? (Pack Flow Control Valve CLOSED)
Bleed Air Source Not available for the PACK
Bleed System Duct Leak
Associated PACK Button OFF
ANY Engine is starting ON GROUND
Associated Engine is starting IN FLIGHT
ANY Engine is start and the APU is the Bleed Source
PACK 1(2) FAIL ECIAS Message
RAM Air Valve BIT is running (PACK 1 OFF)
How is the CPCS automatically controlled in flight?
Logic is divided into Flight Modes
What are the CPCS Automatic Flight Modes?
Ground
Taxi
Takeoff
Climb
Cruise
Descent
Abort
What is the purpose of the CPCS Automatic Flight Modes?
To calculate a target cabin pressure from the outside pressure, max differential pressure limiter and a corresponding pressure rate of variation
During mode transitions or thrust lever transitions what happens to the CPCS?
Higher rates of pressure change might occur for a few seconds
Cabin pressure rate might be TWICE as much for a MAX of 5 seconds
When is Abort Mode activated and what happens to the Cabin Pressurisation?
Activated when the aircraft stops climbing and immediately starts descending (Cruise mode never activated)
Pressure altitude is less than 10,000ft or aircraft is less than 5000ft
Cabin Pressure is scheduled back to take off altitude
What is the Target Cabin altitude when Descent mode is activated?
Landing Field Elevation (Set in the FMS or manually)
What will the Cabin Altitude be at 37,000ft or below?
8,000ft
What is the Maximum Differential Pressure for Takeoff & Landing?
0.2psi
What is the Max differential Negative Pressure?
-0.5psi
What is the max differential overpressure?
8.8psi
What happens if DUMP is selected?
Cabin depressurises to 12,400ft max Cabin Altitude
PACKS & Recirculation Fans OFF
When is the DUMP function used?
Emergency Evacuation
Smoke Evacuation
Fast Cabin Depressurisation
What does the CPCS Automatically do when the DUMP Button is pressed?
Outflow Valve controlled
ECS Packs & Recirculation Fans OFF
At 12,400ft Cabin Altitude, Outflow Valve is commanded Fully CLOSED
What happens when the DUMP Button is pushed OUT after being pressed?
System commanded to normal:
ECS Packs ON
Recirculation Fans ON
What are the components of the CPCS?
Cabin Pressure Controller (CPC)
1 x Cabin Outflow Valve
1 x Negative Pressure Relief Valve
1 x Positive Pressure Relief Valve
1 x Static Port
When is the Negative Pressure Relief Valve Opened?
When the differential pressure exceeds -0.5psi
How is the Negative Pressure Relief Valve Opened?
Spring Loaded, No Electrical Power Necessary
What protects the aircraft structure against damage in the event of negative differential pressure?
Negative Pressure Relief Valve
When does the Positive Pressure Relief Valve Open & How?
8.6psi (Not at the max 8.8psi)
Spring Loaded, no Electrical Power necessary
How many channels does the CPC (Cabin Pressure Controller) have?
2 - alternated each flight
What is the Airflow made up of?
52% Fresh Air & 48% Recirculated Air
In an Abnormal Operation, when are the Recirculation Fans switched off?
BOTH PACKS OFF
On ground during Cabin Warm up with APU as the Bleed Air Source
Cargo Bay FIRE
DUMP Button Pressed
Smoke detected in the Recirculation Bay
When are RECIRC FANS 1 & 2 Commanded OFF?
RECIRC FAN 1 -
ON GROUND, when Pack 1 is OFF and 2 is ON
IN FLIGHT, Speed is greater than 50kts and Pack 1is OFF
RECIRC FAN 2 - Never
How many recirculation fans are there?
2
How many Air Conditioning Packs are there?
2 - PACK 1 & 2
What controls the Bleed Air to each pack?
AMS Controller, through a Flow Control Valve
What Supplies Bleed Air to the Packs?
Respective Engine
What are the Zones controlled by PACK 1 & 2 ?
Pack 1 - CKPT
Pack 2 - PAX Cabin
& are adjusted by the relevant selector knob
How do both zones receive air if operating on a single PACK?
Via a Mixer
What is the primary use for the APU Bleed System?
Ground pneumatic source for Air Conditioning PACKS and Engine Starting
What can the APU Bleed System NOT bed used for?
Anti-Ice System
What prevents Engine Bleed Air flowing to the APU when Engine Bleed Air is the Pneumatic Source?
APU Bleed Check Valve
When is the APU Bleed Valve Commanded OPEN?
APU Switch AUTO
APU Bleed Available
NO APU/Left Bleed Duct Leak
Left Engine Bleed Unavailable
Wing Anti-Ice NOT Requested
When can the APU supply Bleed Air and what controls it?
Both ON GROUND & IN FLIGHT
APU Bleed Valve controls bleed air flow to the pneumatic system
When is the Crossbleed Valve commanded OPEN?
XBLEED Button AUTO
Bleed APU Button pushed OUT for engine Start
Engine 2 Start IN FLIGHT
APU Bleed OFF and Engine 1 Start IN FLIGHT
No Bleed Air source on the opposite side
When is the Crossbleed valve commanded CLOSED?
Bleed Air Leak (Unless Engine Starting)
Engine Fire Handle Pulled
Manifold Side with Pressure above 90psi
How is a Bleed Air overheat detected?
Dual Loop Sensors - when both loops detect an overheat
What happens if a single Loop in the Bleed Air Overheat Detection system fails?
Nothing, monitors as a single Loop
What is the priority order for Bleed Air?
Onside Engine, Offside Engine, APU
When is APU Bleed given Priority?
ON GROUND
APU ON
APU Bleed & Crossbleed Buttons AUTO
Valves Operating Normally
Ground Speed below 50kts, and 30 seconds have passed since touchdown
REF ECS is OFF and REF A/I is not ALL
Aircraft is single engine taxiing
When will Engine Bleed will be unavailable and the APU supply Bleed to both PACKS?
Ground speed greater than 50kts when taxiing with the LEFT engine only
When is the Engine Bleed given priority?
Engine Bleed AVAILABLE
Crossbleed Valve operating normally
ENG REF ECS ON
What type of start does the AMS Controller prioritise during Engine Start with Anti-Ice?
Cross Bleed Start
When is the Engine Bleed System shutdown in an abnormal operation?
Bleed Leak
Overpressure
Failure
How does the Engine Bleed System Work?
Alternatively selects between low and high pressure engine bleed source to maintain adequate and safe bleed supply pressure
How is Engine Bleed Temperature Regulated?
Precooler