B747 Air Systems Flashcards
What is the temperature range for the MAIN DECK Temperature (TEMP) Selectors and the LOWER LOBE Temperature (TEMP) Selectors?
40°F to 85°F
With the EQUIP COOLING selector switch in NORM and the aircraft on the ground without the engines running and the outside air temperature (OAT) is less than 45 degrees F, what happens?
Heated air is exhausted to the Forward Lower Lobe via the Inboard Exhaust Valve
The Forward Equipment Cooling system provides cooling air for flight deck equipment and the Electrical and Electronic (E & E) compartment racks. The Aft Equipment Cooling system is what?
fully automatic
The AFT LOWER LOBE target temperature is displayed in magenta on the ECS synoptic when?
The LLCCAFR Switch is moved from OFF to the LOW AFT position
The AFT LOWER LOBE Temperature Selector is active when?
The LLCCAFR Switch is moved from OFF to the LOW AFT position
The FWD LOWER LOBE target temperature is displayed in magenta on the ECS synoptic when?
The LLCCAFR switch is moved from OFF to the LOW FWD position
The FWD LOWER LOBE Temperature Selector is active when?
The LLCCAFR Switch is moved from OFF to the LOW FWD position
The PACK SYS FAULT light illuminates for what?
Pack overheat or other system fault
The Zone SYS FAULT light illuminates if what?
A Zone Duct overheat is detected
The AFT CARGO HT Switch is normally selected OFF for engine start in order to do what?
Increase the amount of bleed air available for engine start
Under normal conditions, all three Packs will go to high flow when?
If the HI FLOW Switch is pressed ON during cruise and after engine start to cruise altitude
If one Pack is OFF, the other two Packs automatically go to high flow. Two packs in high flow do what?
burn less fuel than three Packs in normal flow
What indications would the crew see in the event of a cabin overpressurization?
Pack 2 shuts down and Cabin Differential pressure indication displayed on Primary EICAS in red
What is the temperature range for the Flight (FLT) DECK Temperature Selector?
65°F to 85°F (TEMP )
What conditions will cause the EQUIP COOLING system to go to closed loop operation?
Supply or Exhaust Fan failure,
Forward Lower Lobe temperature selected to less than 50 degrees F,
MAIN DECK CARGO FIRE Switch ARMED
Selecting the pack High Flow switch to ON in cruise would increase fuel burn by what amount?
.3% per pack
Why is the Aft Cargo Heat switch left OFF until the AFTER START flow?
To provide more airflow during engine start
The EQUIP COOLING Selector is in NORM, the aircraft is on the ground, engines not running, and Outside Air Temperature (OAT) is greater 45 degrees F, what happens?
Heated air is exhausted overboard via the Ground Exhaust Valve
On the ground, with the engines not operating, the Equipment Cooling selector in NORM, and the outside air temperature is 75° F, what is the position of the ground exhaust valve?
Open
In flight, with the Equipment Cooling selector in OVRD, what provides the air flow for equipment cooling?
Cabin differential pressure
Inflight, if the Lower Lobe Cargo Conditioned Air Flow Rate selector is in FWD LOW and the FWD LOWER LOBE Temperature selector is set to 45° F, what is the configuration of the Equipment Cooling system?
The inboard exhaust valve is closed and equipment cooling air is recirculated in a closed loop mode
When does the Equipment Cooling system configure for flight?
When one or more engines on each wing are operating
What does the advisory EICAS message “TEMP CARGO HEAT” indicate?
Overheat detected in aft cargo compartment when aft cargo heat system operating