Oxygen Systems Flashcards
FAR 91 supplemental oxygen requirements
12,500 – Crew must use after 30 Minutes
14,000 – Crew must use for duration
15,000 – Crew must use for duration and passengers supplied
FAR 91.211 pressurized aircraft
Above FL250 must have at least a 10 minute supply of oxygen for each occupant—Emergency Descent
Above FL350—one pilot must be on oxygen at all times—unless a quick-don mask is available
Quick-Don – placed on the face
with one hand within 5 seconds
What if one pilot
goes to lavatory?
Above FL410—at least one pilot on oxygen
Supplemental oxygen
Aviator’s breathing oxygen (ABO) is specified at 99.5% pure oxygen & not more than .005 mg of water per liter.
•Today, all commercial grades of oxygen are produced by the same distillation process
•In the same plant, with the same equipment, to the same specification
•ABO, medical, industrial, & welding oxygen are all the same
•It’s shipped in liquid form to major distribution centers
•there are no separate tank cars or trucks for ABO
•The only difference is the labeling of the cylinder it’s put in, the paperwork, & the cost.
Care and storage of oxygen
•High pressure cylinder of 1,800 to 2,200 PSI
•Containers must be fastened securely in aircraft
•Insure system works properly before flight
•Danger of fire when using oxygen
•Oil, grease, & cosmetics may catch fire if exposed to oxygen during use
•Smoking strictly forbidden when using oxygen
Continuous flow oxygen system
•Oxygen flows from tank, through a pressure regulator that reduces the pressure of the oxygen and then feeds to a mask
•Once the valve is opened, the flow of oxygen is continuous
•When exhaling or when mask is not in use, there is still oxygen flowing
Diluted demand oxygen systems
•Diluter
•Mixes cabin air
•Provides the proper percentage of oxygen for altitude
•Oxygen On-Demand
•Only flows during inhalation
•Required above 25,000 MSL
•Adequate up to 40,000 MSL
Pressure demand
•Normally installed on high-performance turboprop & jet aircraft
•Delivers oxygen under positive pressure
•Forces the oxygen into your lungs
•Required above 40,000 MSL
•DALTON’S LAW—Partial pressure of O2 decreases as total atmospheric pressure decreases
•GRAHAM’S LAW - Gas moves across a membrane from high pressure to low pressure.
