Air Systems Flashcards
Dual bleed light
APU bleed air valve open and No. 1 engine air switch on
OR engine No. 2 bleed air swtich ON and APU bleed valve open and isolation valve open
Isolation valve switch
CLOSE- closes isolation valve
AUTO-
-closes iso valve if both packs are AUTO OR HIGH and both ENG bleed air switches are ON
-
OPEN- isolation valve open
wing body overheat (amber)
LEFT- overheat from bleed air duct leak in left engine strut, IB wing LE, left AC bay, keel beam or apu bleed air duct
Right- overheat from bleed air duct leak in right engine strut, IB wing le, right AC bay
BLEED TRIP OFF light (amber)
excessive engine bleed air temperature or pressure
the related bleed air valve will close automatically
requires reset
TRIP RESET switch
Resets BLEED TRIP OFF, PACK or ZONE TEMP lights
Related bleed air valve opens, pack valve opens, or trim air modulating valve opens
ZONE TEMP lights (amber)
CONT CAB- indicates duct temp overheat or failure of flight deck primary and standby temp control
FWD CAB or AFT CAB- duct temp overheat
ZONE TEMP lights (amber on recall)
CONT CAB- indicates failure of flight deck primary or standby temp control
FWD Or AFT CAB- failure of associated zone temp control
AC Pack Switch
AUTO-
with both packs operating, each pack is at low flow
with one pack operating, operating pack goes to high flow with flaps up
HIGH- pack regulates to high flow
max flow rate on ground with APU bleed air switch on
RAM DOOR FULL OPEN light (Blue)
Ram door is in full open position
Trim air switch
on: trim air pressure regulating and shutoff valve signaled open
off: trim air pressure regulating and shutoff valve signaled closed
PACK light (amber)
- pack trip off or failure of both primary and standby pack controls
- during recall, failure of either primary or standby pack control. extinguishes on master caution reset
EQUIP cooling supply switch or exhaust switch
NORM: normal cooling fan activated or normal cooling exhaust fan activated
ALTN: alternate cooling fan activated or alternate cooling exhaust fan activated
Equip Cooling supply OFF light (amber)
no airflow from selected cooling fan
AUTO FAIL light (amber)
- indicates single controller failure when ALTN light is also illuminated
- indicates dual controller failure if illuminated alone
OFF SCHED DESCENT light (amber)
- airplane descended before reaching planned cruise altitude set
pressurization MANUAL light (green)
pressurization in manual mode
pressurization ALTN light (green)
- illumination of both ALTN and AUTO FAIL lights indicate single controller failure and auto transfer to ALTN mode
- pressurization mode selector in ALTN position
which stages of the compressor is engine bleed air obtained from?
5th and 9th stage of compressor
Engine bleed air valves act as pressure regulator and shutoff valve. how is the valve activated?
DC activated and pressure operated
How is the isolation valve operated?
AC power
The APU bleed air valve will close automatically on shutdown. What powers that valve?
DC controlled and pressure operated
The ram air system provides cooling air for the heat exchangers. The ram air inlet doors are controlled by the packs for cooling. When are they opened/closed?
On the ground or in slow flight with flaps not fully retracted, the doors move to full open.
in cruise they will modulate between open and close
What is the purpose of the deflector doors that are forward of the ram air inlet doors?
they prevent slush ingestion prior to liftoff and after touchdown. They extend on the ground
The equipment cooling system consists of what?
a supply duct and exhaust duct with each having a normal and alternate fan. The supply duct supplies cool air to the flight deck displays and electronic equipment in E and E bay. Exhaust duct collects and discards warm air from that equipment and vents it.
Pressurization is controlled by the cabin pressure control system. It includes how many automatic controllers ?
2– AUTO and ALTN and a manual pilot controlled mode
There are two positive pressure relief valves. They limit max differential pressure to:
9.1 PSI
The negative pressure relief valve prevents what?
prevents external atmospheric pressure from exceeding internal pressure
When is the overboard exhaust valve open?
when the a/c is on the ground and in flight with low differential pressure, the overboard exhaust valve is open and warm air from the E and E bay is discharged overboard.
In flight, the overboard exhaust valve is normally
closed and exhaust air is diffused to the lining of the forward cargo compartment
the overboard exhaust valve is driven open if either pack switch is in
high. This allows increased ventiliation in the smoke removal configuration
When is the overboard exhaust valve closed?
In flight and at higher cabin differential pressures, the overboard exhaust valve is closed and exhaust air goes to the lining of the forward cargo compartment
