Air Systems Flashcards
What is the minimum duct pressured climb and cruise?
After top of descent?
18 psi
10 psi
What does the PRSOV regulate pressure to?
42 psi
What is the temperature limitation of the PRSOV?
232 deg
The APU can provide bleed air or electrical power up to what alt?
It can provide Bleed air + electrical power up to…?
17,000 ft
10,000ft
Above 17,000 is electrical only
In the air, the APU can only supply bleed air to what?
Engine start systems
Cabin pressure and Thermal control
(No anti-ice or hydraulic reservoirs)
APU bleed air is ducted into the aircrafts…?
Which side?
Pneumatic manifold
Left side
If there is Dual Bleed air, what could this cause?
Rupturing of the manifold ducting.
If the Dual Bleed light illuminates on the ground what you do?
Thrust levers to idle, turn APU switch off or investigate
What are the temp and pressure limitations, that shouldn’t be exceeded, on a Bleed air duct system?
Temp = 232 deg c Pressure = 60psi
External pneumatic power can be provided for a ground start when what 2 conditions have been met?
Temp and pressure must be controlled to?
Battery on
Packs off
232 deg, 60 psi
What does the Wing Body Overheat light indicate?
Leak in Bleed air system on a particular side
The flight deck gets its conditioned air from which pack by default?
Left
If the cont temp zone switch is set to OFF what will happen?
The flight deck trim air valve is closed and the temp controls produce 24 deg c demand
The fwd and aft passenger compartments are supplied with air from where?
The mixed manifold
What is the temperature range for the cabin selectors?
18 - 30 deg approx
What is a pack?
Small air compressors that take bleed air from the engines, cool it, filter it, then deliver it to the flight deck, fwd and aft cabin for temperature control.
High pack flow automatic protection, for when a pack fails, is only provided when?
In flight with trailing edge flaps in the up psition
How does a pack work?
It regulates bleed air intake.
Cools it in a heat exchanger cooled by ram air.
An air cycle machine then compresses the air.
It then enters another heat excheanger.
Cool compressed air pasees through water abstraction ducts.
Enters the mixed manifold wich can be regulated there with warmer trim air to make it more comfortable.
What is pressure at msl in psi?
14.7 psi
When carrying out a cross-bleed start, the trust on the operating engine must be increased to obtain a duct pressure of what?
30psi
The PRSOV will close under what 4 conditions?
Startin engine (it PRSOV will close)
Fire switch pulled
Bleed air switch off
Bleed trip off
When will the PRSOV close and BLEED TRIP-OFF light illuminate?
When an over temperature 254 deg or over pressure 220psi is sensed
Recirculation fans are driven by…?
AC motors
Equipment cooling fans are powered by…?
115 v AC
The outflow valve is operated by 2…?
Cabin pressure controllers (CPC)
How much redundancy does the outflow valve have?
How many motors drive it?
How are the motors powered?
Triple redundant
3DC motors
2 automatic by a CPC
1 manual from flight deck
The outflow valve has a safety mechanism which forces it to close when the cabin altitude is above….?
14.500ft
When there is a loss of all sources of AC power, how do you control pressurisation?
Manually
What does SMYD stand for?
Stall Managment and Yaw Damper Computer
Cruise mode is activated when?
Within.025 psi of selected FLT ALT
What is the DIFF PRESS limit at a selected FLT ALT of <28,000 ft
7.45 psi
What is the DIFF PRESS limit at a selected FLT ALT of 28,000 - 37,000 ft
7.8 psi
What is the DIFF PRESS limit at a selected FLT ALT of >37,000 ft
8.35 psi
The two positive pressure relief valves open at what psi differential?
9.1 psi
A negative relief valve opens at what psi differential?
- 1.0
When does the cabin altitude warning activate?
If cabin altitude reaches 10.000ft
Cabin Diff Press Indicator gets outside pressure data from where?
Alternate static ports
