Air Conditioning Flashcards
What is the Flight deck temperature range with the Flight Deck (FLT) temperature selector in AUTO
65f (18c) - 85f (29c)
What valve is controlled when MAN is selected with the flight deck temperature controller
Flight Deck Trim Air Valve (manually controlled)
What does the Zone System (SYS FAULT) light indicate?
- Zone temperature controller overheat
- Zone Temp Controller Fault
- Master trim air valve failed closed
- master trim air valve closed and pack air continues to flow
What is the temperature range with the main deck and fwd and aft lobe temperature selectors in AUTO
40f (4c) - 85f (29c)
Under what conditions would trim air be unavailable to the flight deck, upper deck, crew rest and main deck?
- EICAS advisory message TEMP ZONE displayed
- center section of the bleed duct is isolated
- EICAS advisory message TRIM AIR OFF displayed
- Master trim air switch is off
If trim us not available to the flight deck, upper deck,crew rest and main deck distribution system how is temperature controlled in the cabin
Backup modes control cabin temperature (based on flight deck temperature).
- If the Flight Deck Temperature selector setting is available to PTC, all pack outlet temps are regulated to that set by the Flight Deck Temperature selector (temp range 65°F (18°C) – 85°F (29°C).
- If the Flight Deck Temperature selector setting is unavailable to the PTC, pack outlet temp is regulated to the last flight deck temperature set.
- If the last flight deck temperature set is unavailable to the PTC, pack outlet temp is regulated to and average flight deck temperature of 75°F (24°C).
What target temperature is set to the upper deck and crew rest zone when electrical power is initially applied to the airplane?
75f (24c)
How many pack temperature controllers (PTC) are provided
2 - A&B
How many separate channels are provided in the PTC’s
3 channels for each PTC, 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
- Pushing Pack Reset Switch
+ Pack control, fault detection and overheat protection are all automatic.
+ When overheat or fault detected respective pack closes resulting in pack shutdown
+ if PTC does not switch automatically to other
What would happen if a fault or an overheat of the PTC is detected?
- pack control fault detection and overheat protection are all automatic
- When am overheat or PTC fault is detected the respective pack valve closes resulting in a pack shutdown
What are the 7 temperature zones of the 400f
- Flight deck
- Upper deck
- Crew rest
- Forward main deck
- Aft main deck
- Forward lower lobe cargo
- Aft lower lobe cargo
What is the function if the Lower Lobe Cargo Conditioned Air Flow Rate Selector (LLCCAFR)
Provers forward and aft cargo lobe conditioned air
With the LLCCAFR Switch OFF what controls pack outlet temperature
- all packs have same out put temperature
- all packs output temperature will change to the coolest zone temperature required
What zone and what pack is affected with the LLCAFR selector in the FWD HI
All of Pack 3 conditioned air is sent the the Forward lower lobe cargo compartment
What zone and what pack is affected with the LLCCAFR selector in Aft Hi
All of pack 2 conditioned air is sent to the Aft lower lobe cargo compartment
Explain the position of the LLCAFR selector in BOTH LOW
- 2/3 of pack 3 is sent to the Forward Lower Lobe Cargo Compartment
- 2/3 of pack 2 is sent to the aft Lower lobe cargo compartment
What position of the LLCCAFR selector would result in all packs remaining in high flow during cruise
- FWD HI
- AFT HI
- BOTH LOW
What systems does the center duct provide air to
- Aft cargo heat
- Pack 2
- Trim air
- Lower cargo trim air
- Potable water vacuum air
- Main and lower deck cargo flow through smoke detectors vacuum air
Describe the overheat protection of the aft cargo heat system
- An overheat thermal switch provides protection by opening and closing the overheat/shutoff valve at higher temperatures
- if a system fault or overheat occurs in the lower cargo air conditioning air zone a cargo trim air shutoff valve closes and a backup mode controls the temperature
- positioning the cargo temperature selector from AUTO to MAN or from MAN to AUTO resets cargo air conditioning allows the cargo zone trim air shutoff valve to reopen and clears the backup mode
- positioning the lower lobe cargo conditioned air flow rate selector to OFF also resets cargo air conditioning allows the cargo zone trim air shut off valve to re-open when cargo conditioned air is deselected and clears the backup mode
What is the source of heat for the forward cargo compartment
When the equipment cooling system inboard exhaust valve is open the heated air exhausted from the electrical and electronic (E&E) compartment heats the forward cargo compartment
