Inflight Emergencies: Depressurisation Flashcards
What can cabin pressure loss at altitude be classified as?
- Explosive (may be caused by: collapse of door, window or damaged aircraft structure - air expels out of cabin in a rush)
- Sudden (may be caused by: failure of depressurisation system)
- Gradual (slow leak or AC failure which may not be apparent until aircraft warning systems activate, onset on symptoms are more subtle)
What are the actions FC takes are depressurisation occurs?
- Descend aircraft to a lower altitude (can take nosedive)
What can you see when depressurisation occurs?
- Initial effects of hypoxia
- Sudden boiling of liquids
- Pain in ears and sinuses
- Mist forming in cabin (do not confuse with smoke)
- Air becoming cold and thin
- Need to breathe rapidly
- Disturbance of dust and loose papers
- Discomfort and pain due to trapped gases in the body (relived by bleaching or passing wind)
How does the aircraft indicate depressurisation is occurring?
- Oxygen masks drop from PSUs in lavatories and on all seats
- Cabin lighting illuminates to maximum brightness
- No smoking and fasten seat belt sign illuminate
- Automatic PA instructs passengers how to use oxygen masks (PA repeats 3 times)
- FD manual oxygen deployment switch is activated as a checklist item
(Emphasis on: Use oxygen immediately!)
What are the estimated times of useful consciousness?
43,000ft = 10 seconds
40,000ft = 15 seconds
35,000ft = 45 seconds
30,000ft = 1 minute
25,000ft = 3 minutes
20,000ft = 10 minutes
What is the emergency descent PA?
FC: Attention Cabin Crew! Emergency descent
Indications of depressurisation observed: What to do when no PSU oxygen has been deployed?
- CC return to designated seat
- If no PA or descent - CSM contacts FC
- If no response received - suspect pilot incapacitation
- CSM directs two CC to use supplemental oxygen and proceed to FD
Indications of depressurisation observed: What to do after PSU oxygen has been deployed?
- Complete non-normal checklist recall items
- If no PA or descent - CSM contacts FC
- If no response received - suspect pilot incapacitation
- CSM directs two CC to use supplemental oxygen and proceed to FD
What is the PA when cabin altitude levels off at an intermediate level?
Captain: This is the Captain. It is critical that oxygen is supplied to all passengers. Ensure that your oxygen mask is fitted. Look at the passengers around you. If someone is not wearing an oxygen mask, and you can reach them safely, pull down and fit their mask now and ensure their chin is elevated. Oxygen will flow without the bag inflating.
What is the PA that means CC can complete follow up duties?
FC: Cabin Crew carry out follow up duties
What are the follow up duties?
- Check for passenger injuries and aircraft damage (report to CSM)
- Administer first aid and supply oxygen to passengers if required
- Clear and secure loose objects
- If crew develop symptoms of hypoxia, use supplemental oxygen as required
How to administer first aid oxygen?
- Conscious passengers should be sitting upright
- Unconscious passengers should be in the recovery position and administer oxygen from a portable oxygen cylinder at HI flow, if not possible, provide oxygen in the seated position (keep airway open by elevating jaw), obtain assistance of another passenger
- Use fixed therapeutic oxygen system where relevant (recovering from hypoxia occurs rapidly when adequate oxygen supplied, onset of dizziness during recovery is common but should pass quickly)
- Excessive oxygen may aggravate some respiratory conditions
What to brief the passengers on in depressurisation event?
- Ensure passenger understands seatbelt must remain fastened at all times
- Passenger can use attendant call button for assistance or if they need to leave their seat
(Passengers using portable oxygen bottles must be monitored every 15 min
What should CC do when a passenger using portable oxygen leaves their seat?
Secure bottle by fastening seatbelt
How to secure a portable oxygen bottle on Skybed seats?
- Wrap carry strap around bottle 2-3 times
- Place folded blanket underneath the bottle and place next to the passenger
- Should be placed on side of seatbelt tongue and gauge facing away from the seat
- Thread seatbelt through each loop
