Air Conditioning/Packs Flashcards
The Packs are supplied
by the 10th Stage
Each pack creates cold air by operation of:
An air cycle machine
How does air from the packs enter the cabin?
Conditioned air through the floor level vents; cold air through the gasper vents
Cold air from each pack is routed to:
The onside gasper vents in the cabin and underfloor to the main avionics bay; the right pack also supplies the cold air gasper vents in the cockpit
Pack operation is enhanced while on the ground by:
A bleed-air ejector in each heat exchanger air plenum
Pack low temperature output is limited:
Automatically by a low-limit temperature sensor and valve assembly
The packs are located:
In the AFT Equipment Bay
The Packs operate in high mode when:
The 10th Stage SOVs are closed(APU or external air supply) while on the ground; or when a pack is automatically shut down for over-pressure or over-temperature or is selected off while airborne (APU or 10th stage air bleed-air supply is in use)
In case of pack shutdown, the remaining pack;
Automatically switches to high mode if the pack shutdown was due to over-pressure or over-temperature, or when the affected PACK switchlight is selected OFF
The PACK HI TEMP caution EICAS message results in:
Closing of the related Pack valve
The PACK NOT OFF caution EICAS message is shown if:
Temperature at the related pack outlet is excessive while the pack valve is commanded closed
While in STBY mode, zone temperature is controlled by reference to the:
Related duct temperature sensor
While in MAN mode, zone temperature is:
Accomplished by direct control of the temperature control valve via the temperature selector knob
While in NORM mode, selecting a temperature that differs by more than 3° from the existing zone temperature causes:
The related pack to produce conditioned air at either 35°F or 180°F duct temperature, as appropriate
Ram air into the pressure vessel enters through the:
inlet at the bottom of the vertical stabilizer
The Ram air valve is:
Controlled by the RAM-AIR Switchlight
Ram-Air enter the pressure vessel via:
The Left pack conditioned air duct
Ram air use requires:
at least 250 KIAS
The CKPT HEAT switch controls:
An electric fan and heater for foot warmer and windshield defogging
Air distribution to the cabin and the cockpit is as follows:
Left pack conditioned air: 40% flows to the cabin, 60% to the cockpit; right pack conditioned air: 100% flows to the cabin
The under-floor avionics bay is cooled by the:
Cold air from each pack and by exhaust air from the cockpit electronic displays and instruments
The DISPLAY COOL FAIL status EICAS message indicates:
One or more EFIS or EICAS display fans have failed
The avionics cooling fans begin operation when:
AC power is applied to the aircraft
Cabin temperature is displayed on:
ED2 in degrees celsius only
