11.4 C Pressurisation

Question 1

Why is the interior of a high-altitude aircraft pressurised?
A) To increase the aircraft’s speed
B) To allow passengers and crew to function normally without extra oxygen
C) To reduce structural stress on the fuselage

Answer 1

B) To allow passengers and crew to function normally without extra oxygen

Question 2

What happens to humans when oxygen levels are insufficient at high altitudes?
A) Improved concentration
B) Loss of consciousness and potentially death
C) Enhanced physical performance

Answer 2

B) Loss of consciousness and potentially death

Question 3

At what altitude is the air pressure sufficient for humans to operate without too many problems?
A) 8000 ft (2438 m)
B) 10,000 ft (3048 m)
C) 15,000 ft (4572 m)

Answer 3

B) 10,000 ft (3048 m)

Question 4

What conditions are pressurisation systems designed to produce?
A) Equivalent to sea level
B) Equivalent to approximately 8000 ft (2438 m) or less
C) Equivalent to 10,000 ft (3048 m)

Answer 4

B) Equivalent to approximately 8000 ft (2438 m) or less

Question 5

At what cabin altitude must passengers be on emergency oxygen?
A) 10,000 ft (3048 m)
B) 12,000 ft (3658 m)
C) 15,000 ft (4572 m)

Answer 5

C) 15,000 ft (4572 m)

Question 6

At what cabin altitude must the flight crew start using oxygen?
A) 8000 ft (2438 m)
B) 10,000 ft (3048 m)
C) 15,000 ft (4572 m)

Answer 6

B) 10,000 ft (3048 m)

Question 7

What unit is commonly used to measure atmospheric pressure in aircraft cabin pressurisation systems?
A) Hectopascal
B) Psi
C) Newtons

Answer 7

B) Psi

Question 8

What is the unit of measurement for differential pressure (delta p)?
A) Hectopascal
B) Psi
C) Newtons

Answer 8

B) Psi

Question 9

What is the atmospheric pressure at sea level in psi?
A) 29.92 psi
B) 1013.2 psi
C) 14.7 psi

Answer 9

C) 14.7 psi

Question 10

What is another term for atmospheric pressure?
A) Barometric pressure
B) Hydraulic pressure
C) Differential pressure

Answer 10

A) Barometric pressure

Question 11

What happens to atmospheric pressure as altitude increases?
A) It increases
B) It decreases
C) It stays the same

Answer 11

B) It decreases

Question 12

In which layer of the atmosphere do most commercial flights take place?
A) Stratosphere
B) Troposphere
C) Mesosphere

Answer 12

B) Troposphere

Question 13

Why do aircraft burn less fuel at higher altitudes?
A) Increased air density
B) Reduced drag due to lower air density
C) Higher temperatures

Answer 13

B) Reduced drag due to lower air density

Question 14

Which atmospheric layer contains the ozone layer?
A) Troposphere
B) Stratosphere
C) Mesosphere

Answer 14

B) Stratosphere

Question 15

What is the approximate rate of temperature decrease in the troposphere per 1000 feet of altitude?
A) 0 °C
B) –2 °C to –3.5 °C
C) –57 °C

Answer 15

B) –2 °C to –3.5 °C

Question 16

What is cabin altitude?
A) The actual flying altitude of the aircraft
B) Cabin pressure expressed as an equivalent altitude above sea level
C) The altitude at which passengers must use oxygen

Answer 16

B) Cabin pressure expressed as an equivalent altitude above sea level

Question 17

At approximately what cabin altitude is cabin pressure maintained for passenger comfort?
A) 10,000 ft (3048 m)
B) 8000 ft (2438 m)
C) 15,000 ft (4572 m)

Answer 17

B) 8000 ft (2438 m)

Question 18

What is cabin differential pressure?
A) The pressure inside the fuel tanks
B) The difference between air pressure inside and outside the cabin
C) The ambient air pressure

Answer 18

B) The difference between air pressure inside and outside the cabin

Question 19

What does the cabin rate of climb measure?
A) The speed of the aircraft
B) The rate of change of air pressure inside the cabin, in feet per minute
C) The outside temperature change

Answer 19

B) The rate of change of air pressure inside the cabin, in feet per minute

Question 20

At approximately what cabin pressure altitude must pressurisation be maintained for passenger safety?
A) 10,000 ft (3048 m)
B) 8,000 ft (2438 m)
C) 15,000 ft (4572 m)

Answer 20

B) 8,000 ft (2438 m)

Question 21

What causes metal fatigue in aircraft structures?
A) Frequent pressurisation and depressurisation cycles
B) Flying too fast
C) Weather changes

Answer 21

A) Frequent pressurisation and depressurisation cycles

Question 22

What is the main purpose of the cabin pressurisation system?
A) To increase flight speed
B) To ensure adequate passenger comfort and safety
C) To reduce noise inside the cabin

Answer 22

B) To ensure adequate passenger comfort and safety

Question 23

What does Isobaric Mode maintain in cabin pressurisation?
A) Constant differential pressure
B) Cabin altitude at a single pressure
C) Manual control of pressure

Answer 23

B) Cabin altitude at a single pressure

Question 24

What does Differential Mode maintain?
A) Cabin pressure at sea level
B) Constant pressure difference between inside and outside
C) Rate of climb of the aircraft

Answer 24

B) Constant pressure difference between inside and outside

Question 25

What is Manual Mode used for? A) To automatically control cabin pressure B) For emergency and troubleshooting situations C) To increase cabin altitude

Answer 25

B) For emergency and troubleshooting situations

Question 26

What happens to cabin pressure when cabin altitude increases? A) Cabin pressure decreases B) Cabin pressure increases C) Cabin pressure stays the same

Answer 26

A) Cabin pressure decreases

Question 27

What are the three modes of aircraft cabin pressurisation control? A) Isobaric, Differential, Manual (Emergency) B) Automatic, Manual, Semi-Automatic C) Hydraulic, Electric, Pneumatic

Answer 27

A) Isobaric, Differential, Manual (Emergency)

Question 28

What is the normal cabin pressure descent rate (cabin rate of descent) in feet per minute (fpm)? A) 500 fpm B) 300 fpm C) 1000 fpm

Answer 28

B) 300 fpm

Question 29

What happens to cabin pressure when cabin altitude increases? A) Increases B) Decreases C) Stays the same

Answer 29

B) Decreases

Question 30

What happens to cabin pressure when cabin altitude decreases? A) Increases B) Decreases C) Stays the same

Answer 30

A) Increases

Question 31

How is cabin pressure affected when the outflow valve closes? A) It increases B) It decreases C) It remains the same

Answer 31

A) It increases

Question 32

What type of operation do outflow valves commonly use without requiring electricity? A) Hydraulic operation B) Pneumatic operation C) Electric motor operation

Answer 32

B) Pneumatic operation

Question 33

How does the outflow valve regulate cabin pressurisation? A) By adjusting air inflow to the cabin. B) By varying the rate of air discharge from the cabin. C) By controlling cabin air temperature

Answer 33

B) By varying the rate of air discharge from the cabin.

Question 34

What are the two types of safety valves in cabin pressurisation systems? A) Pressure and temperature valves B) Positive and negative safety valves C) Manual and automatic valves

Answer 34

B) Positive and negative safety valves

Question 35

What is the function of a positive safety valve in aircraft pressurisation? A) To relieve excessive negative pressure inside the cabin B) To relieve excessive positive pressure when maximum differential is exceeded C) To regulate the cabin temperature

Answer 35

B) To relieve excessive positive pressure when maximum differential is exceeded

Question 36

What triggers the opening of a negative safety valve? A) When the pressure inside the aircraft exceeds outside pressure by 0.5 to 1.0 psi B) When the pressure outside the aircraft exceeds inside pressure by 0.5 to 1.0 psi C) When the cabin altitude reaches 8000 ft

Answer 36

B) When the pressure outside the aircraft exceeds inside pressure by 0.5 to 1.0 psi

Question 37

What type of valve is a negative safety valve? A) Outwards opening relief valve B) Inwards opening relief valve C) Rotating valve

Answer 37

B) Inwards opening relief valve

Question 38

What is the primary purpose of dump valves in aircraft pressurisation systems? A) To maintain constant cabin pressure during flight B) To quickly remove air and air pressure from the cabin in the case of an emergency C) To regulate the inflow of air into the cabin

Answer 38

B) To quickly remove air and air pressure from the cabin in the case of an emergency

Question 39

What are the three main flight deck indications that advise the flight crew of pressurisation defects? A) Cabin altimeter, cabin rate of climb indicator, cabin differential pressure indicator B) Cabin temperature gauge, cabin humidity indicator, outflow valve position C) Engine pressure, cabin altitude, oxygen level

Answer 39

A) Cabin altimeter, cabin rate of climb indicator, cabin differential pressure indicator

Question 40

What differential pressure is the aircraft pre-pressurised to during taxi? A) 1.0 psi B) 0.1 psi C) 0.5 psi

Answer 40

B) 0.1 psi

Question 41

What does proportional control do during take-off and climb? A) Keeps cabin pressure the same all the time B) Controls how fast cabin pressure changes to match aircraft climb C) Opens the outflow valves fully

Answer 41

B) Controls how fast cabin pressure changes to match aircraft climb

Question 42

What differential pressure does the cabin pressure controller aim to achieve on touchdown? A) 0 psi B) 0.1 psi C) 1 psi

Answer 42

B) 0.1 psi

Question 43

When are pressurisation system tests required to be carried out? A) Only during flight operations B) After actual or suspected system malfunction C) When passengers complain about discomfort

Answer 43

B) After actual or suspected system malfunction

Question 44

Which document specifies when pressurisation system tests must be performed? A) Pilot’s operating handbook B) Maintenance manual C) Passenger safety briefing

Answer 44

B) Maintenance manual

Question 45

What is one of the conditions that requires a pressurisation system test? A) After initial proof pressure test B) After every flight C) Only when the aircraft is grounded for more than a week

Answer 45

A) After initial proof pressure test

Question 46

Tests must be done after what kind of work on the aircraft? A) After interior cleaning B) After repairs and modifications to the aircraft pressure hull C) After refueling

Answer 46

B) After repairs and modifications to the aircraft pressure hull

Question 47

What is included in the pressurisation system testing? A) General functioning and temperature control B) Engine thrust calibration C) Flight control surface check

Answer 47

A) General functioning and temperature control

Question 48

During pressurisation system tests, what controller operation is checked? A) Fuel flow controller B) Pressurisation controller(s) and normal maximum differential control C) Autopilot controller

Answer 48

B) Pressurisation controller(s) and normal maximum differential control

Question 49

What is the purpose of the safety valve check during pressurisation system testing? A) To check maximum structural differential pressure B) To test the emergency oxygen system C) To inspect cabin lighting

Answer 49

A) To check maximum structural differential pressure

Question 50

Which check is performed to verify that there are no serious leaks in the aircraft pressure hull? A) Safety valve check B) General functioning check C) Leak rate check

Answer 50

C) Leak rate check

Question 51

Where is the cabin pressure controller typically located? A) In the cockpit, within the pilot’s direct view B) Near the flight deck but inside the pressurised portion of the aircraft, out of sight C) In the baggage compartment

Answer 51

B) Near the flight deck but inside the pressurised portion of the aircraft, out of sight