WorksheetsOxygen & Pneumatic System Quiz
Total questions: 50
Worksheet time: 25mins
Aircraft that fly above 18000 ft have
pressure demand system
diluter demand system
diluter pressure system
pressure diluter system
Aircraft that flying at very high altitude where the pressure is too low use
pressure demand system
diluter demand system
diluter pressure system
pressure diluter system
Oxygen can be safe when
the grease and oil is not around
handled during smoking
the oxygen is mixed
not follow correct manual
Pilot and co-pilot use
chemically oxygen generated system
gaseous oxygen system
When the mask is withdrawn
a yellow oxygen flag will appear
a red oxygen flag will appear
a green oxygen flag will appear
a blue oxygen flag will appear
Selector button that allow pure undiluted oxygen to flow is
0%
30%
50%
100%
The passenger oxygen mask will be found in
Passengger System Unit
Passenger Service Unit
Passenger Oxygen Unit
Passenger Personal Unit
The max pressure to be delivered to the passenger is
30psi
1800psi
70psi
100psi
The high pressure form the oxygen bottle will be reduce by
pressure relief valve
pressure reducing valve
low pressure valve
pressure regulator valve
Pressure relief valve is to
increase oxygen bottle pressure
prevent damage if the pressure reducing valve failed
release pressure in the oxygen mask
Portable oxygen bottle is used by the cabin crew
to breath normally
when there is changes in cabin pressure
to allow them to check on the passenger have all got their mask on
What is the material inside the chemical oxygen generator
iron and sodium chloride core
iron and sodium sulphate core
iron and sodium core
iron and sodium chlorate core
The normal charge of oxygen cylinder is
1500 psi
1800 psi
2000 psi
3000 psi
To dissipate temperature during charging the __________ is installed
thermal compensator
pressure relief valve
pressure reducing valve
pressure regulating valve
When max cylinder pressure exceeded
the yellow disk ruptures and green disk appear
the green disk rupture and yellow disk appear
the red disk rupture and yellow disk appear
If the chemical oxygen generator has been used the dolls eye indicator
turn from red to black
turn from orange to black
turn from green to black
turn from yellow to black
Which statement is wrong when the storage bottle indicated low pressure at the cockpit
will give indication (LO PR) on the panel
OXY caution light will illuminate
single chime warning will sound
the oxygen system will cut off
How to measure the moisture level in the oxygen system?
using glass plate
using litmus paper
using hygrometer
A demand regulator in a portable oxygen bottle opens
all the time
when breathing
when 100% selected
Oxygen cylinders are normally fitted with
pressure and quantity gauges.
oxygen purity gauge.
temperature gauge.
Oxygen cylinder test dates
are painted in white on the cylinder
are variable depending on discharge.
may be stenciled on the neck of the cylinder
The cylinder of a portable oxygen set is made of
aluminium
stainless steel
alloy steel
One of the main differences between pneumatic and hydraulic systems is that pneumatic systems
use a motor-operated pump.
need no return line.
produce higher power
What is the function of the safety valve in a pneumatic system?
To prevent an over-temperature.
To stop the regulator dumping if at low pressure.
To prevent high pressure which may cause damage.
Which factor primarily limits the conversion of hydraulic systems to pneumatic operation in
aircraft?
Lack of availability of compressed air
Limitations in capacity for large components
Complexity of control valves
In a high-pressure pneumatic system, what is the main purpose of the pressure regulator?
A. To maintain a constant temperature in the system
B. To control maximum system pressure and off-load the compressor
C. To separate oil and water from the air supply
Why are pneumatic pipelines generally smaller in cross-section compared to hydraulic pipelines?
A. Air has lower viscosity than hydraulic fluid
B. Air is compressible, allowing smaller pipe diameters
C. Higher operating pressures require smaller pipes
During compressor operation, why is the air cooled between each compression stage?
A. To prevent over-lubrication of piston seals
B. To increase efficiency and reduce air temperature rise
C. To meet storage bottle temperature limits
In a four-stage piston compressor, what is the main function of the stepped piston design?
A. To balance air pressure on both sides
B. To progressively reduce the air volume and increase pressure
C. To provide lubrication channels
What is the function of a ground charging valve in a pneumatic system?
To relieve excess air pressure on the ground
To allow charging and testing without running the engine
To bypass the pressure regulator during testing
How does the oil and water trap prevent water from entering the pneumatic system during
manoeuvres?
A. By using a baffle tube with a single outlet hole
B. By heating the air before entry
C. By bypassing air during high-G turns
Why is activated alumina used in a dehydrator?
A. It removes oil vapour from compressed air
B. It absorbs moisture to prevent freezing in components
C. It filters solid contaminants
In pneumatic maintenance, if oil is found in the system filter housing, what should be inspected?
A. Compressor and oil and water trap
B. Dehydrator and storage bottle
C. Pressure regulator and relief valve
How does the high-pressure relief valve operate to protect the system?
A. By bypassing air to the compressor inlet
B. By venting excess air to atmosphere once preset pressure is reached
C. By opening the isolation valve automatically
Why are stack pipes used inside pneumatic storage bottles?
A. To prevent sediment or moisture from entering the system
B. To equalise pressure between bottles
C. To allow high-pressure charging from any point
What is the function of the pressure maintaining valve?
A. To maintain minimum pressure for essential services during pressure loss
B. To prevent overcharging of storage bottles
C. To equalise pressures between main and emergency circuits
Why are pressure reducing valves necessary in some pneumatic systems?
A. To save air during low-demand operation
B. To protect components designed for lower operating pressures
C. To allow more air to enter the high-pressure system
Which safety precaution is critical before loosening any pneumatic fitting?
A. Ensure the component is isolated
B. Ensure the system is depressurised
C. Apply anti-seize compound
In a turbine bleed air system, when is 13th stage bleed air used?
A. When additional cooling is required
B. When 8th stage bleed cannot meet demand
C. During engine starting only
What is the role of the pre-cooler valve in the bleed air system?
To regulate bleed air temperature using fan air
To reduce system pressure to a safe level
To route air to the air conditioning system bypass
What does the bleed thermostat do if duct temperature reaches 230°C?
A. Opens the engine bleed valve fully
B. Reduces control air pressure to modulating valve to reduce airflow
C. Activates over-temperature cockpit warning
What is the maximum duct pressure prevented by the engine bleed air pressure relief valve?
80 psi
100 psi
160 psi
How is potable water pressurised in some aircraft?
By a dedicated electric pump
By bleed air through a pressure reducing valve
By gravity feed from the fuselage tank
What is the main purpose of the purge valve in the air cleaner system?
A. To regulate compressor output
B. To exhaust collected dirt particles to atmosphere
C. To bypass the air cleaner during high demand
Why are duct leak detection systems essential in bleed air systems?
A. To prevent corrosion in ducts
B. To detect overheating due to leaks that may cause fires
C. To identify clogged filters
How does a bi-metallic duct leak detector operate?
A. By producing a voltage change with temperature rise
B. By expanding outer shell to close contacts and complete a circuit
C. By sensing airflow changes in the duct
What material is commonly used for bleed air ducting due to heat resistance?
A. Aluminium alloy
B. Stainless steel or titanium
C. Carbon fibre composite
What is the recommended action if a scratch on a duct exceeds 10% of wall thickness?
A. Leave it in service
B. Smooth it with emery cloth
C. Replace the duct section
In the control cabin, what is the purpose of the isolation valve in a twin-engine pneumatic
system?
A. To link both systems for crossfeed or isolate them during faults
B. To balance pressures between engines
C. To shut off air to the cockpit only
When refitting duct seals, what precaution should be taken to avoid damage?
A. Lubricate with engine oil
B. Cover threads with a sleeve or tape when passing seals over
C. Install seals before aligning ducts
