Air conditioning *** Flashcards
What is the flight deck temperature range with the Flight Deck (FLT) temperature Selector in AUTO?
• 18C to 29C
What valve are you controlling when you select MAN with the flight deck temperature controller?
• Flight deck trim air valve
What does the Zone System (SYS) Fault Light indicate?
- Temperature zone duct overheat or
- Zone temperature controller fault has occurred.
- Master trim air valve failed closed
- Trim air switch off
- Master trim air valve closed and pack air continues to flow.
What is the temperature range with the main deck and forward and aft lobe temperature selectors in AUTO?
• 4C to 29C
Under what conditions would trim air be unavailable to the flight deck, upper deck, crew rest, and main deck?
- EICAS advisory TEMP ZONE is displayed.
- Center section of the bleed duct is isolated.
- EICAS Advisory message TRIM AIR OFF is displayed.
- The Master Trim Air switch is OFF.
If trim air is not available to the flight deck, upper deck, crew rest, and Main deck distribution system, how is temperature controlled in the cabin?
• Operate in Backup modes control temperature
• If the flight deck temp selector setting is available to the PTC, pack outlet
temperature of all packs is regulated to an average temp between 18C and 29C, as set by the Flt Deck Temp selector, or
- If unavailable to the PTC, the last temperature set, or
- If last temp unavailable to the PTC, then 24C
What target temperature is set to the upper deck and crew rest zone when electrical power is initially applied to the airplane?
• 24C
How many pack temperature controllers (PTC) are provided?
• Two – A and B
How many separate channels are provided in the PTCs?
• Each PTC has three separate channels, one for each pack.
What happens if a pack temperature controller (PTC) detects a fault in a pack channel?
• Control of the respective pack switches to the other PTC.
How can you restore pack operation for a failed PTC?
• Push the Pack Reset Switch.
What would happen if a fault or an overheat of the PTC is detected?
• The respective pack valve closes, resulting in a pack shutdown.
What are the 7 temperature zones for the 400F?
- Flight deck/upper deck/crew rest
- Forward and aft main deck
- Forward and aft lower lobe cargo zones
What is the function of the Lower Lobe Cargo Conditioned AIR FLOW RATE Selector? (LLCCAFR)
• Provides forward and aft lobe cargo air conditioning.
With the LLCCAFR Switch Off, what controls pack outlet temperature?
• The flight deck, upper deck, and crew rest zone requiring the coolest temperature.
What zone and what pack is affected with the LLCCAFR selector in FWD HI?
• All of pack three air is sent to the forward lower cargo lobe.
What zone and what pack is affected with the LLCCAFR selector in AFT HI?
• All of pack two air is sent to the aft lower cargo lobe.
Explain the position of the LLCCAFR selector in BOTH LOW.
• 2/3 of pack 3 and 2/3 of pack 2 conditioned air distributed respectively to
forward and aft lower lobe cargo compartments.
What Position of the LLCCAFR selector would result in all packs remaining in High flow during Cruise
FWD HI/AFT HI
BOTH LOW
describe overheat protection of the cargo heat system
an overheat thermal switch provide overheat protection by opening and closing an overheat / shutoff valve at higher temperature
What is the source of heat for the forward cargo compartment?
when the cooling system inboard exhaust valve is open the heated air exhaust from electrical and electronic (E&E) compartment heats the Forward cargo compartment
What is the source of heat for the AFT cargo compartment?
Aft cargo heat is provided by bleed air from the center section of the bleed air duct.
Explain the position of the LLCCAFR with the selector in the following positions:
FWD LOW
AFT LOW
BOTH LOW
1- 2/3 of pack 3 to FWD lower lobe
2- 2/3 of pack 2 to AFT lower lobe
3- 2/3 of pack 3 to FWD lower lobe and 2/3 of pack 2 to AFT lower lobe
What zone and what pack is affected with the LLCCAFR selector in the following positions:
FWD HI?
AFT HI?
1- All of pack 3 air is sent to foward lower cargo lobe
2- All of pack 2 air is sent to the aft lower cargo lobe
What provides equipment cooling with the equipment cooling selector in override?
Differential pressurized air is drawn over equipment and vented overboard through the Smoke/Override valve.
With the loss of trim air, what happens in the air conditioning pressurization
system?
Backup modes control temperature in the cabin, depending on the position of the flight deck temperature selector.
If flight deck temp selector setting is available to PTC will
regulate to achieve an average temp between 18C and 29C.
If flight deck temp selector not available to PTC regulated to achieve last flight deck temp set or
if flight deck temp set is unavailable to PTC will regulate to flight deck temp of 24C
How is the forward cargo compartment heated?
This depends on the position of the LLCCAFR switch and temp selected.
If the LLCCAFR switch is in FWD LOW, BOTH LOW or FWD HIGH and the temp selected is lower than 10C the inboard exhaust valve is closed and equipment cooling is recirculated in a closed loop mode.
With higher selected temp or all other positions of
the LLCCAFC, the inboard exhaust valve is open and the warm equipment cooling air discharges into the forward cargo compartment
The master trim air switch controls the temperature to which zones
5 zones
Flight deck Upper deck Crew Rest Fwd Main Deck Aft Main Deck
