Air Systems Flashcards
(On Air SD) symbology of flight deck/cabin supply duct temp
white- normal
amber- temp exceeds limit
(On Air SD) symbology of flight deck/ cabin selected temp
cyan - normal
(On Air SD) symbology of air conditioning pack
white- commanded off, no air flow
green (vaned)- commanded on, normal flow
amber- commanded off, normal flow
amber (vaned)- commanded on, no airflow
(On Air SD) symbology of cabin rate climb/descent
white- within normal limits
amber- exceeds normal limits
(On Air SD) symbology of outflow valve position
white - normal
blank - no data
(On Air SD) symbology of bleed air valve
white- commanded off (horizontal lines) or on (vertical lines)
green- commanded on with engine running
(On Air SD) symbology of bleed air temperature
white - normal
amber- exceeds upper limit or temperature low with wing/tail anti ice selected on
(On Air SD) symbology of bleed manifold pressure
white - normal
amber - exceeds high and low limits
(On Air SD) symbology of flight deck/ cabin actual temp
white - normal
(On Air SD) symbology of flight deck/ cabin temp dial
blank- auto
white- manual
(On Air SD) symbology of cabin altitude
white- normal
red- above 10,000ft
(On Air SD) symbology of differential pressure
white- normal
amber- above normal limit
(On Air SD) symbology of landing altitude
white - normal (manually input)
magenta - normal (fms generated)
dashes- invalid data
(On Air SD) symbology of outflow valve closed
amber- fully closed
white- not fully closed
(On Air SD) symbology of APU
blanked- apu air not available
white- apu air available, but no demand (pack off)
green- apu air available, with demand (pack auto)
(On Air SD) symbology of isolation valve
white- commanded closed
green- commanded open
amber- valve position disagrees with commanded position
function of avionics cooling switch
operative in flight only for radio rack cooling.
FAN- primary fan operates. if it fails, backup fan comes on automatically
OVRD- fans are off, venturi valve commanded open, venturi airflow cools radios.
(on the ground, venturi valve closed and both fans stay on all the time)
function of the ram air switch
off- closed
on- valve commanded open, ram air enters air conditioning ducts.
in flight, provides ventilation when AC not available
don’t use to ventilate on the ground
function of pack shutdown switch
Both packs will shut down automatically during engine failure on TO below 3000ft or selected off on FMS.
auto- allows pack shutdown during engine failure
ovrd- overrides auto pack shutdown during above conditions
high supply duct temp will also cause auto pack shutdown. Cannot be overridden
function of the Flow switch
Norm- flow control valve solenoid energized for a lower flow rate. must be in NORM for takeoff
high- solenoid de-energized to provide higher flow rate
function of ISOL switch
clsd- isolation valve commanded closed, isolating left and right systems
open- allows crossfeed of left and right pneumatic systems
auto- controlled by pneumatic system controller (PSC). allows auto crossfeed during single source operation with airfoil ice selected on
location of cabin alt and rate info
AIR SD synoptic and secondary engine SD
function of instrument panel flow indicator
only valid if both packs off. single pack on the ground, cooling fan operates.
on- ground with AC off, indicates instrument panel cooling fan airflow
off- ground with AC off, indicates absence of airflow and cooling fan failure
leaving aircraft with apu running for cooling
select one pack off. keeps cooling fan operating, prevent DU overheats if apu shuts down.
function of gasper boost fan switch
provides supplemental airplane ventilation with or without packs operating.
function and operation of cabin press control panel
SELECT illuminates to indicate failure of both auto cabin press controllers
MANUAL illuminates when pushed, then manipulate landing alt and outflow valve manually
FMC packs off takeoff procedure
TO/APP key- push
PACKS- line select ON to OFF
look for packs all off alert on EAD
packs will shut off at throttle advance, come back at 3000 agl.
fwd / aft cargo bin heating and live cargo
in flight, if primary fan operating, fwd cargo compartment electrically heated 60-75F
live animals fwd bin only, fwd of cargo door.
aft bin heated with cabin exhaust air
function of pneumatic overheat detection system (pods)
detects overheat in tail and along wing and tail ice protection manifolds
if failure detected, PODS automatically closes respective anti ice manifold and alerts crew
automatically tested when engine fire test performed
