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WorksheetsQuiz on Aeroplane Aerodynamics
Total questions: 109
Worksheet time: 57mins
Which of the following can be used on the ground?
Turbo fan.
Turbo compressor.
Turbo brake.
The function of an air mass flow control valve is to.
control the airflow out of the cabin.
maintain a reasonably constant air mass flow into the cabin at all altitudes.
ensure that system differential pressure is not exceeded.
Air supplied for pressurisation and conditioning is.
the same for both the above sources.
hottest from an engine compressor bleed.
hottest from a compressor driven by an engine gear box.
The function of the mass airflow control valve is to.
ensure system operating pressure is not exceeded.
maintain a reasonable mass flow of air into the cabin irrespective of aircraft altitude.
ensure that constant airflow out of the cabin is dictated by cabin altitude.
In most pressurization systems, the amount of compressed air delivered to the cabin is.
reasonably constant irrespective of altitude.
constant at any particular altitude but varies for different altitudes.
variable, depending on the amount selected by the cabin rate of change selector.
The purpose of a mass flow controller is to.
ensure that a constant mass of air is delivered to cabin at all times.
allow pilot to select the desired cabin altitude.
ensure the cabin altitude remains constant during cruise at all altitudes.
A refrigerant is used in which of the following?
Air cycle machine.
Pneumatic pump.
Vapour cycle.
In typical vapour cycle system, the sub-cooler.
cools the vapour further to prevent slugging.
delivers extra cooling effect when the aircraft is on ground.
is a heat exchanger to superheat the vapour.
Air conditioning systems.
decrease the temperature of air.
increase and decrease the temperature of air.
increase the temperature of air.
Where is the water trap located in a bootstrap compressor?
At the inlet of the compressor.
At the inlet of the turbine.
At the outlet of the compressor.
When does a 'blower' air conditioning system produce the most air?
At high altitudes.
At low altitudes.
It is not affected by altitude.
In a cabin air recirculation system, recirculated air and fresh air are supplied in the proportions.
50% of fresh air, 50% of recirculated air.
60% of fresh air, 40% of recirculated air.
40% of fresh air, 60% of recirculated air.
An air-to-air heat exchanger is provided to.
reduce the air supply temperature.
provide an emergency ram air supply.
increase the air supply temperature.
Temperature control of cabin air is achieved by.
controlling the water vapour in the supply.
varying the ambient airflow to the heat exchanger.
regulating the amount of air by-passing the cooling system.
If pressurisation air supplies come from an engine compressor, an internal oil leak will.
not contaminate the air.
contaminate the air.
not affect the issue as it is automatically detected and vented overboard.
A cold air unit produces a drop in temperature by.
reducing pressure and driving the units compressor.
driving the units compressor.
reducing pressure.
Heating for pressure cabins is obtained from.
air supply heated by the pressurising process.
driving the units compressor.
A cold air unit allows for cabin temperatures to be.
same as ambient temperature, despite compression heating.
lower than ambient air temperature despite compression heating.
a little more than ambient air temperature.
Conditioned air is.
oxygen added.
moisture removed.
temperature and pressure adjusted.
In a Boot-Strap Air Conditioning supply system the source of compressed air is from.
ram air at the wing leading edge.
gas turbine intake ram air.
gas turbine compressor bleed air.
The temperature within the cabin of the aircraft is normally maintained at.
12ºC to 18ºC.
18ºC to 24ºC.
20ºC to 24ºC.
An aircraft cabin is air conditioned and pressurized in order to.
maintain human efficiency and comfort during flights at high altitudes.
ensure that the air density within the cabin is maintained at a lower figure than outside the cabin in order to prevent moisture precipitation during rapid decompression.
ensure that the pressure within the fuselage is always less than the ambient pressure, thus increasing the fatigue life of the fuselage.
Subsequent to passing through the primary heat exchanger, the supply air in a turbo-fan cold air system flows to the.
inter cooler or secondary heat exchanger.
turbine.
fan.
The heat exchanger in a turbo-fan system is cooled by.
engine bleed air or blower air.
air bled from the main cabin supply duct.
ambient ram air.
When dissipating heat in a vapour cycle system.
vapour converts to a liquid.
the liquid sublimates.
liquid converts to a vapour.
As an aircraft descends from cruising altitude (34,000ft), the cabin altitude must.
decrease.
increase.
stay the same.
The signal line between the controller and discharge valve is leaking. This will cause.
it will not effect on cabin pressure.
the cabin pressure to increase.
the cabin pressure to decrease.
The basic system of cabin pressurisation is to arrange a constant.
inlet and outlet.
inlet and vary the outlet.
outlet and vary the inlet.
With a pressurised aircraft at maximum differential pressure and a cabin pressure increase occurs, the differential capsule in the pressure controller will.
have a constant mass flow.
let pressurisation to be switched off until leaks cause a drop in pressure.
let all pressurising air to be spilled overboard.
A comfortable rate of cabin altitude climb for passengers is.
500 ft. per min.
100 ft. per min.
300 ft. per min.
On touch-down of aircraft.
the outflow valve will be shut.
the cabin pressure will be zero.
the outflow valve will be fully open.
When pressurising the aircraft on the ground for test purposes, internal doors, cupboards etc. must be.
removed.
all open.
all closed.
In the flightdeck of a pressurised aircraft, there is a gauge that shows.
cabin pressure altitude.
aircraft altitude.
cabin differential pressure.
If the pressure controller is set to 0 ft.
maximum differential is reached immediately after take-off.
cabin will not pressurise.
cabin remains at sea level untill maximum differential.
Cabin pressure is maintained by.
controlling the supply of air to the cabin.
controlling the output of the compressor.
controlling the amount of air discharged from the cabin.
Control of rate of change of cabin pressure is.
most important in descent.
most important in ascent.
equally important in descent and ascent.
Cabin rate of climb is shown by.
a double scale on the aircraft.
warning lights.
a special instrument.
Cabin differential pressure is the difference between.
8,000 ft and sea level.
cabin pressure and ambient pressure.
I.S.A. conditions and aircraft altitude.
Cabin altitude in pressurized flight is the.
pressure altitude of the cabin as corrected to mean sea level I.S.A. conditions.
altitude corresponding to cabin pressure irrespective of the altitude for the aircraft.
altitude at which cabin altitude equals outside air pressure.
When an aircraft has reached max. diff. and is at constant level (altitude) the system allows for.
constant mass flow.
pressurisation to be switched off until leaks cause a drop in pressure.
all pressurising air to be spilled overboard.
Pressurisation control ensures that.
at operational altitude the cabin altitude is below 10,000 ft.
pressurisation does not start before aircraft is above 8,000 ft.
the cabin is always maintained at sea level.
When the aircraft has reached its maximum cabin pressure differential the.
discharge valve closes.
discharge valve opens.
mass flow ceases through the cabin.
The principle of cabin pressurisation is.
cabin altitude climbs eventually to that of the aircraft.
cabin altitude will always maintain a constant differential to that of aircraft altitude.
whilst the aircraft climbs to altitude, the cabin climbs to a lower altitude.
When the cabin differential pressure has reached the required value and the height is maintained.
all pressurized air is spilled to atmosphere.
constant mass airflow is permitted through the cabin.
the pressure system ceases to function until the cabin pressure is reduced.
Cabin pressure controller maintains a pre-set cabin altitude by.
regulating the position of the outflow valve.
regulating the position of the inward relief valve.
regulating the mass flow into the cabin.
If cabin height is set lower than airfield height when the aircraft is on the ground with squat switches overridden, then the outflow valve will normally.
open.
remain closed.
not operate.
The cabin altitude is.
the difference between cabin pressure and atmospheric pressure.
the actual height of the aircraft above sea level.
the equivalent height of the aircraft above sea level.
The cabin differential pressure is.
the actual height of the aircraft above sea level.
the difference between cabin pressure and atmospheric pressure.
the equivalent height of the aircraft above sea level.
When air is pressurized, the oxygen content.
remains constant.
increases.
decreases.
During a normal climb from aerodrome level with the pressurization system 'ON'.
Rate of change of cabin pressure is.
automatic
selected by the pilot and controlled by the pressure controller
selected by the pilot and controlled by the spill valve
Cabin differential is determined only by.
the height at which the aircraft is flying
the selected cabin height
the height at which the aircraft is flying and by the selected cabin height
If the pilot selected a cabin height of 8000 ft. whilst taxiing and activated the pressurization system, the cabin pressure would.
decrease to a pressure equivalent to 8000 ft.
remain at ground level pressure
decrease to a pressure equivalent to about 500 ft.
A silencer is installed in a pressurization system to reduce.
the noise from the blowers and/or compressors in the system
the noise from the high speed of airflow within the system
engine noise coming through the ventilators
To avoid discomfort, the rate of change of pressure should be low, particularly.
during descent
when cabin pressure is decreasing
during ascent
If an aircraft is operating at 40,000 ft. the pressurization ensures that.
sea level pressure is maintained in the cabin
the cabin pressure is progressively increased until the operational height is reached
the cabin pressure is equivalent to an altitude of less than 10,000 ft.
When cruising near the operational ceiling, the flight altitude set on the pressurization control panel may be 500 ft. more than the actual flight altitude so as to prevent.
inward relief valve operation
pressure controller hunting
safety valve operation
The cabin rate of climb is shown.
by a differential scale on the aircraft rate of climb indicator
on a specific indicator
as being inside or outside limits by green and red lights, a gauge being used
A water separator would be installed in a pressurization system to.
extract water from the cabin air before it is discharged to atmosphere
collect any rain accompanying the ram air
extract surplus water from the charge air
Cabin pressure controller maintains a particular cabin altitude by control of.
cabin mass air flow
outflow valve position
inward relief valve position
A cabin altitude is protected against reaching an altitude of 13,000 ft. by.
cabin over pressure relief valve
altitude sensor
bellows in the outflow valve
If the cabin altitude increases above the normal maximum.
compressor delivery is automatically boosted
an inward relief valve opens
a warning light comes on in the cockpit
Ditching control is used to.
maintain cabin pressure at sea level
close the outflow valves
achieve rapid depressurisation
Inward vent valves are fitted to.
limit negative differentials
increase ventilation
limit positive differentials
Inward vent valves will operate when.
aircraft altitude exceeds cabin altitude
depressurising after descent
cabin altitude exceeds aircraft altitude
To what position is the inward relief valve spring loaded?.
Closed
Both position
Open
Inward relief valves are interconnected in pressurized aircraft.
to achieve maximum pressure differential
to relieve cabin pressure and allow outside pressure to be greater
to allow controlled pressure during descent
A safety valve will normally relieve at.
lower differential pressure than the discharge valve
higher differential pressure than the discharge valve
negative differential pressure
A negative differential pressure is prevented by.
a blow off valve
a spill valve
an inward relief valve
An inward relief valve will operate.
after an aircraft has landed, to restore ground level conditions is the cabin
when climbing with pressurization OFF
when cabin pressure is lower than ambient pressure
An inward relief valve is installed in a pressurization system to ensure that the pressure hull of an aircraft is not subjected to.
too high an internal pressure
a high negative differential pressure
forces which would cause the aircraft to explode
Failure of the normal maximum differential pressure control is catered for by.
cabin safety relief valves
inwards relief valve
spill valves
How is a serrated rod ice detector bench tested?
Screwdriver torque test
By a motor load test
Motor test and go/no-go gap measurement
Windshield heating provides.
thermal expansion for a tighter fit
impact resistance enhancement
increases strength to resist cabin pressure
The advantage of leading edge fluid de-icing is.
less of a fire hazard
aerodynamic shape is not disturbed
more efficient
On large transport aircraft, the windshield wiper system is.
one system for both sides but with the same power source
independent on each side but with the same power source
independent on each side with different power sources
Prior to securing a leading edge de-icing boot you must.
remove all paint
paint the surface
shave rivet to prevent further abrasion
On a 'hot rod' type of ice detector, it is switched on.
all the time
when selected by the crew
when in the air
Ice formation on wings is due to.
suspended ice crystals melting on contact with the wing and instantly re-freezing
ice crystals forming layers on contact with the wing
supercooled water changing state on contact with the wing
When a vibrating rod ice detector has de-iced, the warning lamp on the flight deck.
goes out immediately
goes out after one more cycle
goes out after a set period of time
De-misting of passenger windows is provided by.
sealed window
an electrical heating element
air from the cabin
A deicer boot is completely bonded to the leading edge to.
provide smoother airflow over leading edge
prevent electrical static build up
provide more efficient deicer cycles
In a cockpit window heater system, the autotransformer.
supplies DC power for heating
supplies AC Power for heating
steps up output for severe weather conditions
Windshield rain repellent is applied.
when rain is on windows and spread by wipers
before rain and spread on window surface by wipers
when in heavy rain so vision is unobscured
Pneumatic rain removal systems.
use engine bleed air at high velocity to remove water droplets from windscreen
are not permitted on large transport aircraft
use a pneumatic motor to drive windscreen wipers
Windscreen wiper torque tests are carried out at.
blade attachment end
centre point of the blade
the shaft end
Windscreen autotransformers.
step down voltage
step up voltage
are used to supply extra current under difficult conditions
An ice deposit formed when liquid water flows over the airframe before freezing, and which is dense, tough and sticks closely to the surface is called.
glaze Ice
rime Ice
hoar Frost
When testing pitot head heaters.
they can only be checked by noting the temperature rise of the probe
they must only be switched on for the minimum time required to check serviceability
they should be switched on for five minutes to allow to stabilise before taking ammeter readings
A rotary knife edge ice detector provides warning of ice by.
increased torque caused by ice formation slowing the rotating wheel and illuminating a warning light in the cockpit
decreased torque caused by ice formation slowing the rotating wheel and illuminating a warning light in the cockpit
ice formation stopping the rotation of a rotary knife edge and illuminating a warning light in the cockpit
Windscreen heating is supplied from.
frequency wild generator, direct to the windscreen
DC generator, via a transformer
frequency wild generator, via a rectifier
A wing thermal anti-ice annunciator is illuminated permanently in flight deck without selection being made. The most probable cause would be.
a short circuit
an open circuit
normal
The usual material for pipelines in a fluid deice system.
stainless steel
Monel
nylon
When operating a windscreen wiper on the ground, make sure to.
use slow wiper only
use water as lubricant when operating
place soft cloth between blade and window
What is run-back ice?
Glaze ice
Rime ice
Glime ice
When the moisture separator is purged in a pneumatic system, it dumps.
just the moisture trap
the whole system
the system between compressor and regulator valve
The pneumatic system pump is a.
centrifugal type
rotor vane type
piston type
In a pneumatic system, the maintainer valve will be fitted in supply lines to.
essential equipment
all equipment
non-essential equipment
High pressure pneumatic source is a.
reciprocating pump
centrifugal Compressor
butterfly pump
High pressure pneumatic pump is a.
reciprocating pump
spur gear
butterfly pump
If the pneumatic water drain trap is left open for a long time it will drain.
between the compressor and the PRV
just the moisture trap
all the system
On a high pressure pneumatic system, if the drain plug for oil and water is left open for long periods of time, the system would.
lose pressure from the compressor side only.
lose pneumatic pressure partially
lose all pressure.
Two compressors driven by separate engines use.
Interconnected to share loads.
NRVs to prevent compressors driving each other.
PRVs.
What is important about the air entering a dry air pump?
It must be filtered.
It must be pressure controlled.
It must be temperature controlled.
What type of compressor is used on a pneumatic system?
Rotary vane type.
Spur gear type.
Positive displacement type.
A cold air unit produces a drop in temperature by.
directing compressed air into a heat exchanger.
air supply to the cabin.
expanding hot air across a turbine which is driving a compressor.
If an altitude of 8000 feet is selected on the cabin pressure controller and provided maximum cabin pressure differential is not exceeded.
8000 feet cabin conditions will be maintained at all aircraft altitudes from sea level
sea level cabin conditions will be maintained to 8000 feet aircraft altitude.
8000 feet cabin conditions will be maintained at aircraft altitudes above 8000 feet.
If cabin pressure is increasing, the cabin rate of change indicator will show.
a rate of climb.
a rate of descent
zero, provided the rate of change is within the normally accepted limits.
. During a normal climb from aerodrome level with the pressurization system 'ON'.
the cabin differential pressure is maintained constant.
the pressurization system does not control pressure until 10,000 ft is reached.
the atmospheric pressure decreases more quickly than the cabin pressure.
