Week 2 Day 4 Flashcards
What does the air non return check valve do?
Stops 8th stage air getting into 5th stage
What stage air do we use for cowl anti ice?
5th stage
What stage air do we use for wing anti ice?
5th and 8th stage air
What do the TAT probes use bleed air for on ground?
Aspiration - creating an airflow over them for more accurate temperature
What does the bleed air isolation valve do?
Isolated left and right sides of bleed air manifold
When does the TAT PRV valve energise open?
When on ground
What does the TAT PRV valve provide air to the TAT and PRV for?
- TAT aspiration
- to keep the PRV open on ground
When is the APU approved to supply bleed air to the system?
On ground only
Where are the bleed air controllers located?
Baggage bay forward bulkhead (RH)
What controls torque motor valves in the bleed air system?
The bleed air controller
What does the 8th stage valve ensure?
Minimum manifold pressures
What does the PRSOV do?
Maintains a maximum manifold pressure of 40psi
Where are the precooked temp sensors mounted?
Handed bleed air ducts (engine side)
What does the fan air valve do?
Provides cooling air to the precooler
What regulates the fan air valve?
Precooler inlet and outlet temp sensors speaking to the BAC
What type of valve is the fan air valve?
- spring loaded open
- torque motor controlled
Which side of the bleed air manifold does external and APU air feed into?
Right
Where are the manifold pressure transducers and what do they communicate with?
Either side of the isolation valve and communicate with the bleed air controllers
What tools are needed to perform a flying control backlash test?
- backlash measurement fixture
- force gauge
How long until you see blue CAS message at end of stab/any flying control rig?
30 seconds
What valves prevent fuel going directly into hopper during refuel?
- non return
- defuelling check valves
What controls the APU load control valve?
The APU ECU
What pressure are the water tanks pressurised to?
42-48psi
What is a bleed air system fail message indicative of?
Failed BAC
What do precooler inlet and outlet temps have to be to generate BLEED AIR HOT CAS messages?
- inlet - 765 degrees
- outlet - 550 degrees
What do bleed air manifold pressures have to be for trigger bleed air pressure high and low CAS messages?
- > 75psi for high pressure
- <5psi for low pressure
During normal operation up to 51000ft, the aircraft only needs _th stage air
5th
What air typical bleed air pressures on ground, in air with engines at idle and on single pack operation (pack switch must be deselected)
- on ground - 14psi
- in flight with throttles at idle - 24psi
- single pack operation - 35psi
What two conditions will create a COOLING TURBINE HOT CAS message?
- compressor outlet temp sensor above 450 degrees
- pack outlet sensor at 160 degrees
Which zones do the left and right air conditioning controllers control?
- left - cabin
- right - cockpit
When do you get an ACS maintenance required CAS message?
If turbine inlet temperature in 50 degrees or lower for >2 mins
When does the turbine bypass valve open?
Above 35000ft
What is the bootstrap principle?
Turbine extracts energy from air and uses it to drive the compressor
What valves regulate bleed air supply into the packs?
Pack inlet valves control by ACC
Are pack inlet valves spring loaded open or closed?
Open
How often do ozone converters need changing?
10000 hours
How many PPM of ozone is left after air has been through converters?
0.1PPM
What does the ACM plenum do?
- provides drainage of water from heat exchanger
- exhausts ram air from what exchangers overboard
What is the basic route of air through the air con pack?
- primary heat exchanger
- air cycle machine compressor
- secondary heat exchanger
- reheated condenser
- air cycle machine turbine
What does the ACM compressor bypass check valve do?
- During initial start up, let’s air bypass the compressor and prevents compressor driving turbine
- also if the compressor seizes, allows air to continue into cabin
What does the turbine inlet control valve do?
- Directs flow from reheater to turbine to ensure ice crystals do not enter turbine
- operates when reheater outlet air drops below 75 degrees