Decompression

Question 1

At what height is recieving oxygen not a problem?

Answer 1

10,000 ft (3000m)

Question 2

What height does the aircraft simulate pressurisation?

Answer 2

1,500-2,100m

Question 3

When does pressurisation take place?

Answer 3

Immediatley after take off (500-600m)

Question 4

When is the aircraft depressurised?

Answer 4

Just before touch down

Question 5

How is air pressurised on an airbus?

Answer 5

air drawn through the engines, compressed and redirected to the cabin.

The air is then cooled and cleaned

air pumped into cabin.

Question 6

How is air pressurised on the B787?

Answer 6

Air is taken directly from the atmosphere

heated

pumped into cabin

Question 7

What would happen to passengers and crew if there was decompression?

Answer 7

1. Ears pop for longer after take-off
2. Become progressively tired without realising
3. If cabin altitude reaches 4,500m, they would begin to suffer from hypoxia.

Question 8

What are the types of decompression?

Answer 8

Slow
Rapid
Explosive

Question 9

What are the causes of a slow decompression?

Answer 9

It may be caused by small cracks in the window or in the fuselage, damaged door or window seals, or a minor fault in the pressurisation system.

Question 10

What are the signs and effects of a slow decompression?

Answer 10

1. The oxygen masks will drop
2. Ears will pop for no reason
3. Euphoria when starting to suffer from hypoxia

Question 11

Define a slow decompression

Answer 11

This is a gradual loss of cabin pressure, which can take more than 10 seconds to equalise with the outside pressure.

Question 12

Define a rapid decompression

Answer 12

It takes between 1 and 10 seconds for cabin pressure to equalise with outside pressure

Question 13

Define extreme decompression

Answer 13

It takes less than one second for pressure to equalise with outside pressure

Question 14

What are the causes of a rapid and explosive decompression?

Answer 14

if the pressurisation system fails suddenly or if part of the fuselage structure is damaged.

Question 15

What are the signs and effects of a rapid and extreme decompression?

Answer 15

1. A loud explosive noise
2. Oxygen masks will drop
3. Pain in ears and sinuses
4. Mist forming in the cabin (reassurance to passengers is needed as they make confuse this with smoke and smoke alarms may be activated)
5. Air becoming thin and cold (on an airbus chemical oxygen may cause the cabin to become warm- may also smell of burning)
6. The need to breath rapidly
7. Sudden disturbance of dust and loose items because of disrupted airflow
8. Sudden boiling of liquids risking scalding
9. Bursting of carbonated drinks, containers, sealed packages, and inflated items.

Question 16

What is the oxygen paradox?

Answer 16

When a person is hypoxic, and they are experiencing euphoria, they may feel they do not want an oxygen mask- you MUST ensure that they put their mask on and KEEP it on. They may feel sick when oxygen is delivered.

Question 17

What are the effects of a lack of oxygen to the brain?

Answer 17

Capabilities are adversely affected without the person being aware of the symptoms. The person thinks that they are more competent than they are (lack of self-criticism).

Question 18

What is the time of usefulness at 40,000ft?

Answer 18

18 seconds

Question 19

What is the time of usefulness at 35,000ft?

Answer 19

30-50 seconds

Question 20

What is the time of usefulness at 30,000ft?

Answer 20

1-2 minutes

Question 21

What is the time of usefulness at 28,000ft?

Answer 21

2-3 minutes

Question 22

What is the time of usefulness at 25,000ft?

Answer 22

3-5 minutes

Question 23

What is the time of usefulness at 15,000-18,000ft?

Answer 23

30+ minutes

Question 24

How much is time of usefulness reduced for CCMs?

Answer 24

40%

Question 25

What would the indications of a decompression be in the flight deck?

Answer 25

Audible and visual alarms will activate on the flight deck when rising cabin altitude passes through 10,000ft alerting flight crew to take action.

Question 26

What would the indications of a decompression be in the cabin?

Answer 26

1. Oxygen masks dropping 2. Fasten seat belt signs on 3. AIRBUS: Exit markings and locations will illuminate automatically 4. B787: 5x loud charms, cabin lights increase to full brightness, and PA volume to max.

Question 27

What are the stages of the decompression drill for the cabin crew?

Answer 27

1. Fit nearest oxygen mask 2. Sit down on nearest seat (on a passengers lap if necessary) 3. Fasten seat belt (or get passenger to hold you) 4. Breath normally 5. Note time on wristwatch (time one minute) 6. Wedge service cart between seats and put brakes on. 7. Shout commands Then the FSM/CSS will make decompression PA in the ORG. Then the flight crew should make 'Cabin Crew emergency decent' x2 on the PA.

Question 28

What commands must cabin crew shout during decompression?

Answer 28

Grab mask, pull down, fit mask, breath normally, fit your own mask before helping others, fasten seatbelt, stay calm, keep mask on, etc.

Question 29

Why is it important that we hear the flight crew PA during a decompression?

Answer 29

To know that they are in control.

Question 30

What happens if there is no PA from the flight deck?

Answer 30

1. Fit portable oxygen and go to the flight deck 2. Enter emergency access code 3. Ensure all pilots are on flight crew oxygen, if not quickly don oxygen masks. 4. Wait for them to make the emergency PA "Cabin Crew emergency descent" x2

Question 31

What indicates cabin crew can stop shouting demands? What does it indicate?

Answer 31

When they hear the interphone from the flight deck which says "FSM to interphone immediately" x2. It indicates that the aircraft has levelled off and oxygen is no longer needed.

Question 32

What should all cabin crew do once they have hear the PA announcement "FSM to interphone immediately"

Answer 32

1. Get up. 2. Check on all other cabin crew. 3. Check toilets, galleys, and the crew rest areas for anyone incapacitated. 4. Secure the galleys, turn off electrics, and shut off water supply. 5. Brief ABPs sat at exits to keep other passengers away from the exit. 6. Administer first aid and PO as required 7. Check for fire and structural damage 8. Update FSM on status of cabin, passengers and crew.

Question 33

What should be done with the oxygen masks when they are no longer required?

Answer 33

They should be bundled and put behind the seats.