Supplemental Oxygen & Pressurization
What Regulation is Supplemental Oxygen requirements?
91.211
What are Cannulas and what are their limitations?
A Cannula is a type of oxygen deliver system that only provides oxygen through the nose; It is not approved about 18,000ft
What kind of oxygen is to be used for supplement oxygen procedures?
Aviation Oxygen; 100% Oxygen
What is Histotoxic Hypoxia?
Body cells are unable to make use of oxygen; Drugs/Alcohol
What 2 types of oxygen systems are there?
Fixed and Portable
What cabin pressure altitudes requires use of supplemental oxygen of required minimum flight crew?
-above 12,500msl including 14,000msl if the duration is more than 30 minutes in duration -Above 14,000msl for the entire flight
Time of Useful Consciousness: 30,000
1-3 Minutes
What are the three important instruments of pressurization systems?
1. Cabin Differential Pressure 2. Cabin Altimeter 3. Cabin Rate-of-Climb
What are the benefits of high altitude flying?
1. Fuel efficiency 2. Wx Avoidance
Time of Useful Consciousness: 40,000
15-20s
Time of Useful Consciousness: 28,000
2.5-3 Minutes
Time of Useful Consciousness: 18,000ft
20-30 Minutes
Time of Useful Consciousness: 25,000
3-5 Minutes
Time of Useful Consciousness: 15,000ft
30 Minutes or more
Time of Useful Consciousness: 35,000
30-60s
Time of Useful Consciousness: 22,000
5-10 Minutes
Time of Useful Consciousness: 45,000
9-15s
What is important about maximum differential pressure?
Aircraft fuselages are only designed to withstand a certain about of difference in pressure; exceeding these limits will cause structural failures and resulting in decompression
What is the definition of decompression?
Aircrafts inability to maintain desired pressure differential
What is required for operations of a pressurized cabin aircraft above flight level 350?
At least one pilot at the controls must wear and use an oxygen mask; that supplies oxygen at all times or automatically supplies oxygen above 14,000msl
What is Hypemic Hypoxia?
Blood is unable to transport oxygen; Carbon Monoxide/Smoking
What are the benefits of a continuous flow type oxygen system?
Cheapest method; Oxygen flows at constant rate based on a regulator setting. Does waste oxygen at lower altitudes
What are the five methods of regulation oxygen flow?
Continuous Flow Altitude Adjustable Altitude Compensating Demand System Pressure-Demand System
What are the symptoms of Hypoxia?
Decreases in Brain Function Decreases in vision Cyanosis- Blue coloration of extremities
How does an oxygen Diluter Demand system work?
Designed for aircraft capable of flying above FL350; Provides oxygen when pilot inhales; Supplies oxygen with a mixture of cabin air; Has switches that allow switching to full 100% oxygen
What are symptoms of Hyperventilation?
Dizziness Weakness Fainting Tingling of lips, hands and feet Spasms Tightness in the forehead/temples
Pressurized aircraft must have at least a 10 minute supply of oxygen for each occupant above what altitude?
FL250
What is the function of the dump valve?
Gives control to pilots to dump cabin air into the atmosphere if required.
What are signs of a heat stroke?
Hot feeling(without sweating) Dizziness/Fainting Rapid heart rate and breathing Nausea and vomiting Confusion/Disorientation Seizures
How can you aid a passenger suffering from decompression sickness?
Immediately descend to a lower altitude Provide Supp. Oxygen Land to get them to hospital
What are signs of Decompression sickness in passengers?
Joint Pain Tingling sensations Seizures Unconsciousness
What is considered a rapid decompression?
Lungs decompress faster than the cabin; No likelihood of lung damage
Why do we have to use Aviation 100% oxygen?
No impurities, no water vapor and this prevents freezing
Are passengers required to use supplemental oxygen above 15,000msl?
No, just provided with supplemental oxygen
What is considered an explosive decompression?
Occurs in less than 0.5 Seconds; Change in cabin pressure that is quicker than lungs can decompress. Potentially dangerous and causes physical harm to persons
How does a Pressure-Demand system work?
Oxygen is pumped continuously to the mask under positive pressure; Ensures oxygen delivery up to FL450
What two types of oxygen masks are typically used in General Aviation?
Partial Rebreathers and Sequential breathers
What is special about operations of pressurized aircraft below FL410 equipped with quick-donning type oxygen masks?
Pilots are not required to use oxygen masks above FL350
What does the cabin pressure control system include?
Pressure Relief Valve Vacuum Relief Valve Outflow Valve Safety Valve
What does the safety valve consist of?
Pressure Relief valve Vacuum relief Dump Valve
What is the function of the vacuum relief valve?
Prevents ambient pressure from exceeding cabin pressure by allow external air to enter the cabin.
What is the function of pressure relief valve?
Prevents cabin pressure from exceeding a predetermined differential pressure above ambient pressure
How do you recover from a decompression event?
Quickly dawn oxygen mask and make an emergency descent
Hyperventilation is a result of what?
Rapid breathing in stressful situations; creates a lack of Carbon Dioxide in the blood stream
What causes Hypoxia?
Reduced partial pressure of oxygen at altitude; not enough pressure for oxygen to force its way into the blood stream.
What does the Outflow valve do?
Regulates air exit which allows for constant inflow of air to the pressurized area.
How does Altitude compensating oxygen flow work?
Regulator automatically changes oxygen flow rate with changes in altitude; Most do not turn on until reaching 8000 to 10,000ft
What is a sequential breather mask?
Sturdier masks with better molding to the face. Check valves and ports allows a mixture of oxygen and outside air into the mask. Approved up to 30,000ft
What is differential cabin pressure?
The difference between cabin pressure and atmospheric pressure
What is required for pressurized cabin aircraft above FL350 when one pilot leaves the flight controls?
The other pilot is required to use an oxygen mask until the other pilot has returned to the flight controls
What are the requirements of a quick-donning type oxygen mask?
The oxygen mask must be able to be placed on the face within 5 seconds with one hand; and supply oxygen properly sealed and secured
How can you monitor to monitor risk of hypoxia?
Use a pulse oximeter to monitor blood oxygen levels
What does the FAA recommend in regards to supplemental oxygen on night flights?
Use supplemental oxygen above 5000ft
What is a partial rebreather mask?
Uses an external plastic bag that inflates when exhaled. Stores unused oxygen so it can be inhaled in the next breath. Approved up to 25,000ft
What is motion sickness?
When there is a disagreement between what the body feels and what the body sees
All occupants must be provided with supplemental oxygen above what cabin pressure altitude?
above 15,000msl