CABIN PRESSURIZATION SYSTEM

Question 1

Aircraft are flown at high altitudes for two reasons:

Answer 1

1. An aircraft flown at high altitude consumes less fuel for a given airspeed than it does for the same speed at a lower altitude because the aircraft is more efficient at a high altitude.
2. Bad weather and turbulence may be avoided by flying in relatively smooth air above the storms.

Question 2

It is a process in which conditioned air is pumped into the cabin of an aircraft or spacecraft, in order to create a safe and comfortable environment for passengers and crew flying at high altitudes.

Answer 2

CABIN PRESSURIZATION

Question 3

A ______________ typically maintains a cabin pressure altitude of approximately 8,000 feet at the maximum designed cruising altitude of an aircraft

Answer 3

CABIN PRESSURIZATION SYSTEM

Question 4

The _____________ permits a reasonably fast exchange of air from the inside to the outside of the cabin. This is necessary to eliminate odors and to remove stale air.

Answer 4

PRESSURIZATION SYSTEM

Question 5

In airliner, _____________ is proportional to the pressure outside the aircraft in, order to reduce the stress in the aircraft fuselage.

Answer 5

CABIN PRESSURE

Question 6

In typical commercial passenger flight, the _____________ is programmed to rise gradually from the altitude of the airport of origin to a regulatory maximum of 8,000 feet or 2,400 meter.

Answer 6

CABIN ALTITUDE

Question 7

The ___________ is maintained while the aircraft is cruising at its max altitude then gradually reduces during the descent of the aircraft, until it matches the ambient air pressure at the destination.

Answer 7

CABIN PRESSURE

Question 8

The actual height above sea level at which the aircraft is flying.

Answer 8

AIRCRAFT ALTITUDE

Question 9

The temperature in the area immediately surrounding the aircraft.

Answer 9

AMBIENT TEMPERATURE

Question 10

The pressure in the area immediately surrounding the aircraft.

Answer 10

AMBIENT PRESSURE

Question 11

Cabin pressure in terms of equivalent altitude above sea level.

Answer 11

CABIN ALTITUDE

Question 12

The difference in pressure between the pressure acting on one side of a wall and and the pressure acting on the other side of the wall.

Answer 12

DIFFERENTIAL PRESSURE

Question 13

In aircraft air conditioning and pressurizing systems, it is the difference between cabin pressure and atmospheric pressure.

Answer 13

DIFFERENTIAL PRESSURE

Question 14

Physiological problems arising due to failure of cabin pressurization (4)

Answer 14

HYPOXIA
ALTITUDE SICKNESS
DECOMPRESSION SICKNESS
BAROTRAUMA

Question 15

The lower partial pressure of oxygen at altitude reduces the alveolar oxygen tension in the lungs and subsequently in the brain, leading to sluggish thinking, dimmed vision, loss of consciousness and ultimately death.

Answer 15

HYPOXIA

Question 16

Hyperventilation the body’s most common response to hypoxia, does help to partially restore the partial pressure of oxygen in the blood but it also causes carbon dioxide to outcast raising the blood pressure and inducing alkalosis.

Answer 16

ALTITUDE SICKNESS

Question 17

The low partial pressure of gases principally nitrogen but including all other gases, may cause dissolved gases in the bloodstream to precipitate out, resulting in gas embolism are bubbles in the bloodstream.

Answer 17

DECOMPRESSION SICKNESS

Question 18

As the aircraft climbs or descends, passengers may experience discomfort or acute pain as gases trapped within their bodies expand or contract.

Answer 18

BAROTRAUMA

Question 19

It provides cabin pressure regulation, pressure relief, vacuum relief, and the means for selecting the desired cabin altitude in the isobaric and differential range.

Answer 19

CABIN PRESSURE CONTROL SYSTEM

Question 20

It has a function of damping of the cabin pressure.

Answer 20

PRESSURE CONTROL SYSTEM

Question 21

These are used to accomplish damping of the cabin pressure

Answer 21

CABIN PRESSURE REGULATOR
OUTFLOW VALVE
SAFETY VALVE

Question 22

It controls cabin pressure to a selected value in the isobaric range and limits cabin pressure to a preset differential value in the differential range.

Answer 22

CABIN PRESSURE REGULATOR

Question 23

It is used to prevent the maximum differential pressure, for which the fuselage was designed, from being exceeded.

Answer 23

DIFFERENTIAL CONTROL

Question 24

It is determined by the structural strength of the cabin and often by the relationship of the cabin size to the probable areas of rupture, such as window areas and doors.

Answer 24

DIFFERENTIAL PRESSURE

Question 25

It is a combination pressure relief, vacuum relief and dump valve

Answer 25

CABIN AIR PRESSURE SAFETY VALVE

Question 26

It prevents cabin pressure from exceeding a predetermined differential pressure above ambient pressure.

Answer 26

PRESSURE RELIEF VALVE

Question 27

It prevents ambient pressure from exceeding cabin pressure by allowing external air to enter the cabin when ambient pressure exceeds cabin pressure.

Answer 27

VACUUM RELIEF

Question 28

It actuates the dump valve.

Answer 28

FLIGHT DECK CONTROL SWITCH

Question 29

When this switch is positioned to ram, a solenoid valve opens, causing the bulb to dump cabin air into the atmosphere.

Answer 29

FLIGHT DECK CONTROL SWITCH

Question 30

The degree of pressurization and the operating altitude of the aircraft are limited by several critical __________.

Answer 30

DESIGN FACTORS

Question 31

Primarily the fuselage is designed to withstand a particular maximum _______________.

Answer 31

CABIN DIFFERENTIAL PRESSURE

Question 32

It indicates the difference between inside and outside pressure.

Answer 32

CABIN DIFFERENTIAL PRESSURE GAUGE

Question 33

This gauge should be monitored to assure that the cabin does not exceed the maximum allowable differential pressure.

Answer 33

CABIN DIFFERENTIAL PRESSURE GAUGE

Question 34

It is also provided as a check on the performance of the system.

Answer 34

CABIN ALTIMETER

Question 35

Advantages of cabin pressurization system (4)

Answer 35

•HELPS TO MAINTAIN AIRCRAFT CABIN PRESSURE AT HIGH ALTITUDE WITH GREAT PRECISION AND ACCURACY
•IT RESPONDS TO MINOR CHANGES IN CABIN PRESSURE WITH RESPECT TO AIRCRAFT ALTITUDE
•IT GENERATES AMBIENT ATMOSPHERE FOR PASSENGERS AND PREVENTS PASSENGERS FROM PHYSIOLOGICAL PROBLEMS
•IT ALSO MAINTAIN AND MONITOR CABIN AIR QUALITY AS PER DIRECTED BY WORLD HEALTH ORGANIZATION

Question 36

It is defined as the inability of the aircraft’s pressurization system to maintain its design pressure differential

Answer 36

DECOMPRESSION

Question 37

This can be caused by a malfunction in the pressurization system or structural damage to the aircraft

Answer 37

DECOMPRESSION

Question 38

Two categories of decompression

Answer 38

EXPLOSIVE DECOMPRESSION AND RAPID DECOMPRESSION

Question 39

A change in cabin pressure faster than the lungs can decompress, possibly resulting in lung damage

Answer 39

EXPLOSIVE DECOMPRESSION

Question 40

Normally, the time required to release air from the lungs without restrictions, such as masks, is 0.2 seconds

Answer 40

EXPLOSIVE DECOMPRESSION

Question 41

Most authorities consider any decompression that occurs in less than 0.5 seconds to be explosive and potentially dangerous.

Answer 41

EXPLOSIVE DECOMPRESSION

Question 42

It is a change in cabin pressure in which the lungs decompress faster than the cabin.

Answer 42

RAPID DECOMPRESSION