Air Systems Flashcards
Where does APU bleed air enter the pneumatic manifold
Left of the isolation valve
Where does external pneumatic air enter the pneumatic manifold
Right of the isolation valve
What are all the sources that provide air for the pneumatic system
External air, APU, and 5th and 9th stage engine bleeds
An 800 aircraft has three air conditioning zoned. The temperature controllers are in NORMAL and trim air is ON. The two packs will supply at what temp
A temp for the zone requiring the most cooling
What happens when an engine bleed switch is placed to ON
If engine bleed air and electrical power are available, the valve opens
What does an illuminated engine BLEED TRIP OFF light indicate
Excessive engine bleed air pressure or temperature condition, engine bleed valve closes automatically
How is engine bleed air temperature regulated
Controlled engine fan air circulates through a precooler
Air for starting the engines is supplied from
The left or right pneumatic manifold
Which statements are correct regarding the pneumatic manifold pressure sensors
AC powered; located in left&right pneumatic manifolds
What do the duct pressure pointers indicate when one pack valve switch is placed to OFF with the APU providing bleed air and the isolation valve in AUTO
APU bleed pressure shows on both pointers
What occurs when the APU bleed air switch is placed to ON
DC power signals valve to open, APU bleed air opens the valve if RPM is above 95%
What is the power source for the pneumatic isolation valve
AC power
Which statement best described the isolation valve function
Isolates left & right sides of the pneumatic manifold and is closed during normal operation
What action causes the pneumatic isolation valve to open when the switch is in the AUTO position
Placing an engine bleed air switch or pack switch to OFF
What is the function of the DUAL BLEED light
To warn when the APU may be back pressured by engine bleed air
Which valve and switch combination causes the DUAL BLEED light to come on
APU bleed valve OPEN & right engine bleed switch ON, with the isolation valve OPEN
What is the crew action for an illuminated DUAL BLEED light prior to engine start
No action. Dual Bleed Light is normal during engine start with APU bleed air
Which condition illuminates a WING-BODY OVERHEAT light
All answers are correct
What engine stages provide bleed air
The 5th and 9th stage
The 9th stage engine bleed air is the primary source of bleed air for pneumatics when the engine is at cruise thrust
False
The engine bleed valves are located
Downstream of the 9th stage modulation/ shutoff valve
How are the bleed valves operated
They are electrically controlled and pneumatically operated
Excessive engine bleed air pressure or temperature will cause what condition to occur
A bleed trip
If the APU bleed valve and switch are open, the valve will automatically close with APU shutdown
True
A right WING-BODY OVERHEAT light could indicate a bleed leak in all of the following except
In the keel beam area
The potable water system pressurization line connects to which part of the pneumatic manifold
The left side
The Engine Bleed Valve Trip pressure sensor is located
Before bleed air reaches the engine bleed valve
The Engine Bleed Valve Trip temperature sensor is located
After the engine bleed air passes the engine bleed air passes the engine bleed valve and precooler
What limitation is imposed when the DUAL BLEED light is illuminated
No more than idle engine power is allowed
External pneumatic air can be used to start the number 1 engine
If the isolation valve is open
The APU provides bleed air directly to
The left side of the pneumatic manifold
The engine bleed valve must be open for ENGINE anti-ice to be available
False
What is the normal source of conditioned air for the flight deck with both packs operating(500)
The left pack prior to the mix manifold
What is the indication on the respective AIR MIX VALVE position indicator when a pack valve closes(500)
Full COLD
Which is correct for pack operation
Bleed sir flows through a heat exchanger, the ACM compressor, a second heat exchanger, then the ACM turbine
What does an illuminated PACK TRIP OFF light indicate(500)
Pack valve closed by compressor discharge or turbine inlet overtemp or duct overtemp
When are the RAM DoOR FULL OPEN lights extinguished
In cruise with low pack temperature
On the ground , what is the proper indication of the ram door position lights
RAM DOOR FULL OPEN lights illuminated
What is the function of the turbofan in the ram air exit duct(500)
Augments ram airflow when a pack is operating on the ground or inflight with the flaps not up
Which statement is correct regarding the air conditioning system deflector doors
The doors extend on the ground to prevent FOD ingestion
What is the purpose of the recirculation fan
Reduced pack air loads & engine bleed demand
Where is filtered RECIRC FAN air discharged
Into the mix manifold
What occurs when a pack switch is placed to the HIGH position with the other pack switch in AUTO and the RECIRC FAN switch in AUTO(500)
Respective pack goes to high flow & recirc fan shuts down
Which statement is correct regarding single pack operation with one pack switch in AUTO and one pack switch OFF inflight
Remaining pack goes to high flow in flight when flaps are up
With the RECIRC FAN switch at AUTO , and both pack switches at AUTO, which statement is correct regarding the recirculation fan operation(500)
Recirc fan shuts down when either pack switch is placed to HIGH
What does an illuminated DUCT OVERHEAT light indicate(500)
Duct has overheated and mix valves have driven full COLD
How is hot air removed from the circuit breaker panels and the E&E compartment equipment
By either the main or alternate equipment cooling fans
Which statement is correct regarding operation of the flow control valve(500)
Closes when cabin pressure differential reaches 2.5 psid
What does an illuminated EQUIP COOLING OFF light indicate
No airflow from the respective equipment cooling fan
How is the forward cargo compartment heated when cabin differential pressure is above 2.5 psi with the forward outflow valve closed(500)
The recirc fan maintains airflow around the outside of the compartment
Which systems are reset by means of the TRIP RESET switch(500)
DUCT OVERHEAT, PACK TRIP OFF & BLEED TRIP OFF
How are the pack & isolation valve switches positioned for a BLEEDS-OFF takeoff
The right pack in AUTO, the isolation valve switch in AUTO, and the left pack in AUTO
E&E compartment cooling air flow is normally provided by the
Equipment cooling fan
With the recirc fan switch in AUTO, the fan(500)
Operates if one pack is turned OFF and the other is in AUTO
Inflight, when both air conditioning packs are operating and the Recirc Fan is in Auto, placing a pack switch to High(500)
All answers are correct
With both packs operating , if air conditioning smoke appears in the cockpit and in the cabin, the most likely source is(500)
Left air conditioning pack
Overheat temperature sensors that will cause a pack trip are located in the(500)
ACM compressor discharge duct, turbine inlet duct, and supply duct
When parked at the gate, external conditioned air temperature_______controlled by the packs
Is not
Bleed air for the pack is_____as it passes through the primary heat exchanger
Cooled
Each pack has a temperature selector. The selector on the left controls the temperature for(500)
Flight deck
With the pack switch turned OFF, the pack valve closes and the mix valves______(500)
Move to full cold
With the aircraft airborne, when is the forward outflow valve closed(500)
When the recirculating fan is operating
Which model 737 has a TRIM AIR switch on the overhead panel
800 model
Which of the following models has a Forward Outflow Valve
500
What occurs when the FLT GND switch is placed to FLT with the aircraft on the ground, packs ON, doors CLOSED, and engine bleed air avail(500)
The main outflow valve modulates as necessary to maintain the aircraft at 200 feet below departure field elevation
What altitude is set in the STANDBY CAB ALT indicator when operating in AUTO during the receiving aircraft check
200 ft below landing field elev
What altitude is set in the STANDBY CAB ALT indicator during the receiving aircraft check when operating the flight with the SAtANDBY pressurization system(auto system inop)
Takeoff field elev minus 200ft
What does an illuminated OFF SCHED DESCENT light indicate
Aircraft descending without having reached the selected cruise altitude
Which statement is correct regarding the outflow valve position indicator
Operates in all pressurization modes with AC power available
All of the following items control the ram air system ram door and exhaust louvers except
The pressurization controller
When is the RAM DOOR FULL OPEN light illuminated
On the ground, or in flight with the flaps extended
Illumination of the amber pressurization OFF SCHED DESCENT light indicates what situation
The airplane is descending prior to reaching the selected flight altitude
What is the maximum allowable differential pressure for takeoff
.125 psid
The air conditioning packs may be operated in HIGH during a bleeds on takeoff
False
With the aircraft at the maximum certified altitude and one pack operating, what is the lowest cabin altitude that can be maintained
8000 ft