CH2 AIR SYS Flashcards
What does the AUTO setting on the Forward Equipment Cooling Switch indicate?
Forward equipment cooling mode is controlled automatically.
What happens when the Forward Equipment Cooling Switch is turned Off?
Both forward equipment cooling supply fans and vent fan are commanded off, smoke/override valve is commanded open, forward cargo heat becomes inoperative, forward cargo air conditioning becomes inoperative, and OVRD illuminates.
This setting is typically used in emergencies or specific operational scenarios.
What does the illuminated OVRD (amber) indicate?
Smoke/override mode is operating due to manual off selection, supply fan failure, or automatic selection by the smoke detection system.
What is the function of the Flight Deck Temperature Control?
Selects the target flight deck temperature between 18° C and 29° C.
Turning the control toward C or W adjusts the desired temperature.
What is the mid position setting on the Flight Deck Temperature Control?
Approximately 24° C.
What occurs during ground operations when the Flight Deck Temperature Switch is set to full C or W?
The flight deck boost fan may be commanded on, increasing flight deck air flow and slightly reducing passenger cabin air flow.
What does the AUTO position on the PACK Switches indicate?
The pack is automatically controlled
What does it mean when the PACK Switch is set to OFF (amber illuminated)?
Both associated cabin air compressors are not running
This can occur automatically during engine start, due to pack or compressor high temperature, or when manually selected.
What happens when the TRIM AIR Switch is set to ON?
The trim air valve is commanded open
What does it mean when the TRIM AIR Switch is in the OFF position (ON not visible)?
The trim air valve is commanded closed and FAULT illuminates
What does an illuminated FAULT (amber) indicate for the TRIM AIR Switch?
The trim air valve is failed closed or commanded closed due to overheat
It may also indicate that the TRIM AIR switch has been selected off.
What does the ON position indicate for the Recirculation Fans (RECIRC FANS) Switches?
Provides automatic operation of the associated recirculation fans
What occurs when the Recirculation Fans (RECIRC FANS) Switch is set to OFF (ON not visible)?
The selected recirculation fans do not operate
An EICAS advisory message is displayed in this case.
What does the EQUIP COOLING AFT switch set to AUTO control?
Aft equipment cooling mode is controlled automatically.
What occurs when the EQUIP COOLING AFT switch is set to Off?
Both aft equipment cooling supply fans and vent fan are commanded off, override valve is commanded open, and aft cargo heat becomes inoperative.
OVRD ILLUMINATES
What does the OVRD indication mean?
SMOKE/OVRD mode is operating due to manual selection of Off, failure of both equipment cooling supply fans, or automatic selection by the smoke detection system.
What is the function of the CABIN TEMP control?
Provides automatic passenger cabin temperature control.
What temperature range can the CABIN TEMP control set?
Between 18° C and 29° C.
What does the Air Conditioning Reset (AIR COND RESET) Switch do?
Resets air conditioning faults and attempts to restart normal operation
It also resets any trim air valves held closed due to overheat, control failure, or valve failure, attempts to reset a failed recirculation fan, and resets fault protection.
What are the two positions of the Alternate Ventilation (VENTILATION) Switch?
NORM and ALTN
What happens when the Alternate Ventilation (VENTILATION) Switch is set to ALTN?
The Forward and Aft Outflow Valves are repositioned towards the ten and one o’clock positions when below 13,000 ft altitude and not on ground.
What are the two types of heaters mentioned in the air conditioning system?
- Shoulder Heaters
- Foot Heaters
What does pushing the Air Conditioning Reset (AIR COND RESET) Switch attempt to reset?
- Air conditioning faults
- Trim air valves
- Failed recirculation fan
- Fault protection
What is the significance of the NORM position in the Alternate Ventilation (VENTILATION) Switch?
Environmental control system is configured for normal operation
What does the SHOULDER HEATER Control LOW setting indicate?
The electric heater operates on low setting.
The shoulder heater adds heat to the conditioned air at variable temperature settings up to HIGH
What is the function of the SHOULDER HEATER Control when turned?
The electric heater adds heat to the conditioned air flowing in at shoulder level at variable temperature settings up to HIGH.
Available in-flight only.
What does the FOOT HEATER Control LOW setting indicate?
The electric heater is off.
The foot heater adds heat to the floor plate at variable temperature settings up to HIGH.
What happens when the FOOT HEATER Control is turned?
The electric heater adds heat to the floor plate at variable temperature settings up to HIGH.
Available on ground and in-flight when pack and recirculation fans are on.
Fill in the blank: The SHOULDER HEATER is available _______.
in-flight only.
Fill in the blank: The FOOT HEATER is available on ground and in-flight when _______.
pack and recirculation fans are on.
What does the LOW setting on the FWD CARGO FLOW selector indicate?
Normal ventilation flow for maintaining perishable, temperature sensitive, or any cargo other than animal carriage
What is the function of the HIGH setting on the FWD CARGO FLOW selector?
High ventilation flow demanded from the air conditioning system to prevent cargo odors from entering the passenger cabin
This setting is also used for live animal carriage or other odorous cargo.
Fill in the blank: The FWD CARGO A/C control provides _______ for the forward cargo compartment.
automatic temperature control
True or False: The LOW setting on the FWD CARGO FLOW selector is suitable for live animal carriage.
False
The LOW setting is for normal cargo, while HIGH is used for live animals or odorous cargo.
What does the Forward Cargo Air Conditioning Control provide?
Automatic temperature control for the forward cargo compartment
What temperature range can be set using the Forward Cargo Air Conditioning Control?
4° C to 27° C
The mid position (12 o’clock) approximately sets the temperature to 16° C.
What happens when the Forward Cargo Air Conditioning Control is turned to OFF?
Disables heater and cargo refrigeration unit
Normal cargo heating is provided by the forward E/E exhaust ventilation system.
What is the target temperature when the BULK CARGO TEMP switch is set to AUTO?
21° C
What indicates that the BULK CARGO TEMP switch is commanded off?
AUTO not visible
What does an OFF light illuminated amber indicate for the BULK CARGO TEMP switch?
Bulk cargo heater overheat or switch selected off
What does the OFF light status signify when not visible for Forward Cargo Air Conditioning?
FWD cargo air conditioning selector is OFF or functioning properly
What indicates that the Forward Cargo Air Conditioning is inoperative?
OFF light illuminated amber when selector is in any position other than OFF
Fill in the blank: The Forward Cargo Air Conditioning Control allows setting the desired target temperature between _______.
4° C and 27° C
True or False: The Forward Cargo Air Conditioning Control can only provide cooling and not heating.
False
It can disable the heater and provide normal heating through the exhaust ventilation system.
What does the HUMID switch control?
Flight deck humidification system operates automatically when ON
The HUMID switch is located on the overhead panel.
What does the AUTO position of the OUTFLOW VALVE switch indicate?
Outflow valve controlled automatically
What happens when the MAN position of the OUTFLOW VALVE switch is selected?
Outflow valve is controlled manually
This bypasses automatic outflow valve control and cabin altitude limiter, and AUTO extinguished
How is the landing altitude set manually using the Landing Altitude (LDG ALT) Selector?
Pull ON, then rotate
Landing altitude followed by MAN displayed on EICAS
What happens when the LDG ALT Selector is pushed?
Landing altitude set automatically from FMS
Landing altitude followed by AUTO displayed on EICAS
When are pressurization system indications displayed automatically?
When landing altitude is set to MAN
EITHER OUTFLOW VALVE MAN
CABIN ALT ABOVE NORMAL RANGE
CABIN DIFF PRESS ABOVE NORMAL
AIR SYNOPTIC
SELECTED EICAS MSG
What color indicates a normal cabin altitude?
White
Indicates that the cabin altitude is within the normal range.
What does an amber cabin altitude indication signify?
Above normal range
Indicates that the cabin altitude is higher than the normal range.
What does a red cabin altitude indication represent?
Excessive cabin altitude
What does a plus sign (+) in cabin altitude rate indicate?
Rate of climb
What does a minus sign (-) in cabin altitude rate indicate?
Rate of descent
What color indicates a normal cabin differential pressure?
White
Indicates that the cabin differential pressure is within the normal range.
What does an amber cabin differential pressure indication signify?
Above normal range
Indicates that the cabin differential pressure is higher than the normal range.
What does a red cabin differential pressure indication represent?
Excessive cabin differential pressure
What does ‘M’ (amber) indicate in Outflow Valve Control Source?
Manual control
What does a blank indication in Outflow Valve Control Source signify?
Automatic control
What does ‘OP’ stand for in Outflow Valves Position?
Open
What does ‘CL’ stand for in Outflow Valves Position?
Closed
What does the pointer in Outflow Valves Position indicate?
Varies position to reflect outflow valve position from open to closed
Provides a visual representation of the outflow valve’s status.
What does ‘AUTO’ (white) indicate in Landing Altitude Selection?
Altitude set automatically from FMC
What does MAN (amber) indicate in the pressurization system?
Altitude set by landing altitude (LDG ALT) selector.
What is the purpose of the Power Electronics Cooling System (PECS)?
It is the liquid cooling system for electronics.
How can the status display for PECS be viewed?
Push a Systems (SYS) display switch, then select the status (STAT) synoptic key.
What does the liquid quantity display show?
Left and right system reservoir quantities as a percentage of normal service level.
1.00 IS NORMAL
What does LO (amber) indicate on the liquid quantity display?
The reservoir requires servicing.
What does RF (white) indicate on the liquid quantity display?
Reservoir servicing is recommended.
What does OF (white) indicate on the Liquid Quantity Display?
Displayed when the reservoir is over-full
When is a single liquid cooling loop displayed?
When only one forward external power source is connected and selected ON
What happens to the forward cargo selected temperature display when the forward cargo air conditioning system is off or inoperative?
The display is blank.
This indicates that no temperature is being selected for the forward cargo compartment.
What does a green symbol indicate in the Cabin Air Compressor Synoptic Indications?
The associated compressor is running and developing flow.
This is a key indicator for the operational status of the cabin air compressor.
What does a white symbol indicate in the Cabin Air Compressor Synoptic Indications?
The associated compressor is not developing flow.
This indicates that the compressor is off and not functioning.
Fill in the blank: Selected temperatures are indicated in _______.
magenta
Fill in the blank: Actual temperatures are indicated in _______.
white
What does a white, low-intensity indicator for the compressor signify?
Compressor invalid: Signal from associated compressor is invalid or missing
What does the load shed symbol (white) indicate regarding associated compressors?
Associated compressor (L1, L2, R1, R2) has load shed
What does a green pack symbol indicate?
Pack is running and developing conditioned airflow
What does a white pack symbol signify?
Pack switch - OFF or both associated cabin air compressors are off and not PACK L(R) status message
What does an amber pack symbol indicate?
Pack is not developing conditioned inflow when commanded to run
PACK SW AUTO AND PACK LR STATUS MSG
What does a ‘Pack signal invalid’ indication look like?
White, low intensity.
Indicates that the pack signal is not correctly functioning.
What does a green indication for the Recirculation Fan signify?
Fan on - Upper fan or one of two lower fans is developing flow.
What does a white indication for the Recirculation Fan signify?
Fan off - Upper fan or both lower fans are not running.
What does a white, low intensity indication for the Recirculation Fan indicate?
Fan invalid on.
What does a green symbol indicate in the Trim Air Valve Synoptic Indications?
Valve open
What does a white symbol represent in the Trim Air Valve Synoptic Indications?
Valve closed
What does an amber symbol indicate in the context of Trim Air Valve Synoptic Indications?
Valve failed open or Valve failed closed
What does a low intensity white symbol signify in the Trim Air Valve Synoptic Indications?
Valve invalid
What is the indication for an associated pack in standby cooling mode?
EICAS advisory message PACK MODE L (R) displayed.
What does the EICAS advisory message ANTI-ICE PACKS indicate?
Compressor inlet anti-ice failure.
What is displayed when the cabin occupants data is missing or invalid?
Blank.
The system does not provide information on cabin occupants if data is not entered correctly.
Fill in the blank: The number of cabin occupants is entered on the _______.
Cabin Attendant Panel