1 - Air systems Flashcards
An APU switch with only a flow bar showing indicates
It is armed for automatic operation
How is the APU bleed controlled and actuated?
Electrically controlled and electrically actuated
How are engine bleed valves controlled and actuated?
Electrically controlled and pneumatically actuated
When will engine bleed valves open?
When pressure is sufficient to cause airflow
What does an engine bleed switch with a flow bar off indicate?
The valve is armed or has a fault
How is an isolation valve controlled and operated?
Electrically controlled and operated
What does a duct leak light indicate?
A leak anywhere in the bleed system
What does a bleed light indicate?
Excessive bleed air temp. This causes the engine bleed valve to automatically close
What does a high stage light indicate?
Excessive pressure. This causes the HP valve to automatically close for the remainder of the flight
Why would the Compartment Temperature Inoperative (INOP) Lights Illuminate
fault in the zone temperature controller
Compartment Temperature Control is OFF
the trim air switch is OFF
Describe the AUTO position of the Compartment Temperature Controls
- automatic compartment temp control
- pack output temperature is determined by the cabin temperature controller.
What does the OFF position do concerning the Compartment Temperature Control?
closes the compartment trim air valve
* the compartment temperature INOP light illuminates
TRIM AIR Switch ON/OFF
What occurs in each position?
ON – the trim air valve is commanded
open.
Off – the trim air valve is commanded
closed.
PACK RESET Switches. Why use them?
Resets an overheated pack if the pack has cooled to a temperature below the overheat level.
Pack INOP Lights. Why illuminated?
the pack is overheated
* fault in the automatic control system
Pack Off Light, hvað þýðir það?
PACK VALVE Closed
PACK Control Selectors. Hvaða mode eru í boði?
STBY MODE
N (normal) – constant, moderate temp
C (cool) – full cold operation
W (warm) – full warm operation
Foot og shoulder heaters. Virka bara á high hvenær?
HIGH er bara í boði í flugi.
What will cause the Equipment Cooling SMOKE Light to illuminate?
Smoke is detected in the forward equipment cooling ducts.
Describe the Alternate (ALTN) Equipment Cooling Switch
activates the alternate supply fan
On the 757-200ER activates the
auxiliary fan, if the alternate supply fan fails.
The Equipment Cooling Overheat (OVHT) Light illuminates for 3 reasons.
insufficient airflow (on the ground)
the supply fan is inoperative
the alternate supply fan is inoperative
When you rotate the Cabin Altitude AUTO RATE Control, what is it doing?
You are setting a limit for cabin altitude rate of climb or descent during auto control.
What is the function of the DETENT position?
Establish an approximately 500 fpm climb and 300 fpm descent
What has happened when you see AUTO Inoperative (INOP) Light
Either:
AUTO 1 and AUTO 2 cabin altitude control functions are inoperative or,
MAN mode is selected
Ef þú setur Cabin Altitude mode selector á AUTO þá er _____ valve controlled automatically
outflow
Það kviknar á hvaða ljósi ef þú setur MANUAL á Cabin altitude mode selector?
AUTO INOP light illuminates
What is the takeoff and landing Cabin differential pressure limit/placard?
.125 PSI
Þú færð Cabin Altitude ljós, when cabin altitude exceeds ______ feet, extinguishes when cabin altitude
descends below ____ feet.
10,000, 8500
What is the function of the High Altitude Landing Switch?
Reprograms system logic to initiate AURAL and VISUAL alerts at 14,650’ instead of 10,000’
what is the purpose of the Bleed Air System Isolation Switch? To open or close the _____ VALVE.
ISOLATION
If you notice the ISOLATION VALVE light, what is occurring?
The isolation valve position disagrees with the commanded position.
The engine BLEED AIR switches open when?
They open when engine bleed air is available. Pneumatic actuated. Held þú verðir að hafa ákveðið mikinn þrýsting svo þetta opnist.
What are the 3 reasons the Engine Bleed Air OFF light illuminate?
The engine bleed air valve is closed:
* automatically due to a system fault
* the switch is OFF
* the engine is not running
Why would a DUCT LEAK Light occur? A ____ temperature ____ air leak is detected.
high, bleed
Why would a BLEED Light occur?
The engine bleed air temperature is excessive.
Why would a HI STAGE Light occur? Engine bleed system pressure is excessive or
the engine _____ pressure bleed air valve is automatically locked closed.
high
What would cause a APU Bleed Air VALVE Light to Illuminate (amber)
APU bleed air valve position disagrees with commanded position.
How many temperature zones in the 757
Three, Flight Deck and two Cabin zones.
What occurs when there is an internal pack overheat?
The pack valve closes and the pack is shut down automatically.
During an internal pack overheat what lights will you see?
The ____ ____ light illuminates.
EICAS advisory L or R PACK OFF
PACK TEMP indications.
PACK OFF
What happens when you shut off the LEFT RECIRC FAN? The overboard _____ valve will open. Maintenance action is then required
exhaust
Why turn off the RIGHT RECIRC FAN?
To provide a more rapid exchange of air.
Where does the Flight Deck get its air? From the RIGHT PACK/LEFT PACK only.
LEFT
Where does the Flight Deck get its air if the LEFT PACK has failed? The flight deck receives air from the ___ manifold.
mix manifold
How much does our Fuel Flow increase with a recirculation fan off?
.3%
How does the FORWARD E/E system get cool?
The left recirculation fan draws air through the forward E/E system and returns it
to the ____ manifold.
mix manifold
What happens if the TRIM AIR system is off? (fyrir hitastig)
The packs attempt to maintain all compartments at an average temperature.
How does the forward equipment cooling system work?
The system has a supply fan that
draws cooling air from the cabin and forces it through the equipment racks and
avionics
After the forward equipment is cooled, where does the air go?
The air is then exhausted into the air conditioning mix manifold by the
left recirculation fan.
What occurs while the forward equipment is cooled and there is a low differential pressure?
The overboard exhaust valve automatically opens and most of the air is exhausted overboard
What lights will you view if a supply fan fails?
Equipment cooling OVHT light illuminates
EICAS advisory EQPT OVHT displays
What should be done after the supply fan fails?
Pushing the ALTN EQUIP COOLING switch, (an alternate supply fan is activated)
The 757-200ER has what backup for cooling of the ESSENTIAL avionics and electrical equipment
If both supply fans are inoperative an auxiliary fan automatically operates to provide cooling for essential avionics and electrical equipment.
In the 757-200ER what is the backup power source?
The hydraulic driven generator.
What happens when smoke is detected in the equipment cooling system?
SMOKE light illuminates.
EICAS advisory FWD EQPT SMOKE displays when smoke is detected in the equipment cooling system.
What happens automatically when smoke is detected in the equipment cooling system? one or both recirculation fans turn ___, one or both AC packs switch to ___ flow, the overboard exhaust ____ opens
off, high, valve
How would you describe the cargo heat system?
Completely automatic.
What protects the fuselage from excessive pressure differential?
Positive pressure relief valves and negative pressure relief valves operate
independently from the pressurization control system to protect the fuselage
against excessive pressure differential.
When will the CABIN ALT and CABIN ALTITUDE lights illuminate while the HIGH ALTITUDE LDG switch is on?
If the cabin altitude climbs above 14,650 feet . The lights extinguish and the EICAS message blanks when the cabin altitude descends below 11,800 feet
The ____ switch automatically closes the outflow valve when the cabin altitude exceeds _____ feet. Some models are auto and manual mode. Some models are auto only.
aneroid, 11,000