AC ENVIRONMENT AND AUXILIARY SYSTEM

Question 1

Aircraft are flown at high altitudes for TWO REASONS:

Answer 1

Consumes less fuel

Bad weather and turbulence

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

This prevents rapid changes of cabin altitude that may be uncomfortable or cause injury to passengers and crew.

Answer 3

CABIN PRESSURIZATION SYSTEM

Question 4

A cabin pressurization system typically maintains a cabin pressure altitude of approximately __________ at the maximum designed cruising altitude of an aircraft.

Answer 4

8,000 FT.

(2,400 METER)

Question 5

It is proportional to the pressure outside the aircraft, in order to reduce the stress in the aircraft fuselage.

Answer 5

CABIN PRESSURE

Question 6

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

Answer 6

CABIN PRESSURE

Question 7

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

Answer 7

AIRCRAFT ALTITUDE

Question 8

the temperature in the area immediately surrounding the aircraft.

Answer 8

AMBIENT TEMPERATURE

Question 9

the pressure in the area immediately surrounding the aircraft .

Answer 9

AMBIENT PRESSURE

Question 10

cabin pressure in terms of equivalent altitude above sea level.

Answer 10

CABIN ALTITUDE

Question 11

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

Answer 11

DIFFERENTIAL PRESSURE

Question 12

PHYSIOLOGICAL PROBLEMS ARISING DUE TO FAILURE OF CABIN PRESSURIZATION

Answer 12

Hypoxia

Altitude sickness

Decompression sickness

Barotrauma

Question 13

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 13

HYPOXIA

Question 14

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 (CO2) to out-gas, raising the blood pH and inducing alkalosis.

Answer 14

ALTITUDE SICKNESS

Question 15

The low partial pressure of gases, principally nitrogen (N2) but including all other gases, may cause dissolved gases in the bloodstream to precipitate out, resulting in gas embolism, or bubbles in the bloodstream.

Answer 15

DECOMPRESSION SICKNESS

Question 16

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

Answer 16

BAROTRAUMA

Question 17

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 17

CABIN PRESSURE CONTROL SYSTEM

Question 18

an outflow valve, and a safety valve are used to accomplish these functions.

Answer 18

CABIN PRESSURE REGULATOR

Question 19

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 19

CABIN PRESSURE REGULATOR

Question 20

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

Answer 20

DIFFERENTIAL CONTROL

Question 21

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 21

DIFFERENTIAL PRESSURE

Question 22

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

Answer 22

CABIN AIR PRESSURE SAFETY VALVE

Question 23

It prevents cabin pressure from exceeding a pre determined differential pressure above ambient pressure.

Answer 23

PRESSURE RELIEF VALVE

Question 24

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

Answer 24

VACUUM RELIEF

Question 25

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

Answer 25

FLIGHT DECK CONTROL SWITCH

Question 26

It is designed to withstand a particular maximum cabin differential pressure.

Answer 26

FUSELAGE

Question 27

It indicates the difference between inside and outside pressure.

Answer 27

CABIN DIFFERENTIAL PRESSURE GAUGE

Question 28

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

Answer 28

CABIN DIFFERENTIAL PRESSURE GAUGE

Question 29

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

Answer 29

CABIN ALTIMETER

Question 30

Advantages of Cabin Pressurization System

Answer 30

Helps to maintain aircraft cabin pressure at high
altitudes.

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 maintains and monitor cabin air quality as per directed by World Health Organization (WHO).

Question 31

Disadvantages of Cabin Pressurization System

Answer 31

DECOMPRESSION

Question 32

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

Answer 32

DECOMPRESSION

Question 33

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

Answer 33

DECOMPRESSION

Question 34

two categories of decompression

Answer 34

Explosive decompression

Rapid decompression

Question 35

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

Answer 35

RAPID DECOMPRESSION

Question 36

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

Answer 36

EXPLOSIVE DECOMPRESSION