Flight (FLT) DECK FAN Switch - ON
packs off/on
TRIM AIR Switch - ON (what does it do)
master trim air valve open and flight deck, upper deck, and main deck zone trim air valves operate automatically
TRIM AIR Switch - OFF (5)
Equipment (EQUIP) COOLING Selector - STBY (3)
Equipment (EQUIP) COOLING Selector - NORM (3)
Equipment (EQUIP) COOLING Selector - OVRD (4)
High (HI) FLOW Switch - ON
* EICAS memo message PACKS HIGH FLOW displays
AFT CARGO Heat (HT) Switch - ON (3)
Aft Cargo Temperature (TEMP) Light
* overheat shutoff valve closes
PACK Reset (RST) Switch - push
* restarts pack after automatic shutdown if fault no longer exists
Pack System (SYS) FAULT Light
• pack overheat or other system fault has occurred
may illuminate briefly when automatically or manually switching from pack temperature controller A to B or B to A
PACKS Control Selectors - NORM
On the ground, with the engines not operating, the Equipment Cooling selector in NORM, and ambient temperatures moderate or high, the warm exhaust air is _____
With lower ambient temperatures _____
ducted overboard through the ground exhaust valve.
the ground exhaust valve is closed and the inboard exhaust valve opens. The warm equipment cooling
exhaust air discharges into the forward cargo compartment (the system is configured for flight)
There are __ temperature zones:
six • flight deck • upper deck • forward and aft main deck • forward and aft lower lobe cargo zones
The packs are controlled by __ identical pack temperature controllers (PTCs)
two, (A and B)
Control of the packs switches automatically to the other PTC at touchdown. If a PTC detects a fault in a pack channel, control of the respective pack switches to the other PTC
Each PTC has __ separate channels
three, (one for each pack)
If a PTC detects a fault in a pack channel, control of the respective pack switches to the other PTC
Each pack valve has __ flow rates
two, (normal and high)
During cruise, normal flow minimizes bleed air demand on the engine to reduce fuel consumption
Aft cargo heat is provided by bleed air from the ____ bleed air duct
center
Shoulder and foot heat is available ____
in flight
On the ground, with the engines not operating, the Equipment Cooling selector in NORM, and ambient temperatures moderate or high, the warm exhaust air is ____
With lower ambient temperatures ____
ducted overboard through the ground exhaust valve.
the ground exhaust valve is closed and the warm exhaust air is ducted into the forward cargo
compartment (system is configured for flight)
On the ground, when ____ the system
configures for flight.
one or more engines on each wing are operating
Positioning the Equipment Cooling selector to STBY ____
closes the ground exhaust valve to manually configure the airplane for flight
With the Equipment Cooling selector in NORM or STBY, the system normally
configures to ____ if a single internal fan fails.
closed loop mode
In closed loop mode, the inboard exhaust valve is closed
With _____ operating, the flight deck equipment cooling source valve directs conditioned air into the flight deck electrical equipment
two or three packs
The equipment cooling system provides cooling air for flight deck equipment and the electrical and electronic (E &E) compartment equipment racks.