Installed Oxygen System
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System description
Limitations
Normal Procedures
Emergency Procedures
Oxygen System
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77 Cubic foot tank installed in the
aft tail section
– Service through the baggage
compartment.
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O2 line is plumbed above the
headliner to the distribution
manifold
Control panel/annunciator panel is
mounted on center console just left
of the flap lever
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Master switch
Fault annunciation
Quantity indication (tank pressure)
Distribution quantity indication
(pressure to distribution manifold)
Oxygen Limitations
• Cannulas are certified up to FL180 as per FAR part 23.
Oxygen masks are required above FL180
• FAR 91.211 requires the use of O2 below the aircraft
maximum certified altitude.
– Above12,500 MSL for more the 30 minutes or,
– Anytime above 14,000 MSL
– Make available for passengers above 15,000 MSL
• Note:
– The O2 Required light will illuminate when the aircraft has
reached a pressure altitude of 12,000 feet and the system is off
Duration Table
• Based on a
77 cu ft tank
• Residual
oxygen
below FL200
is not
factored into
duration
table
• Includes
additional 5%
safety margin
What is the oxygen duration for a flight at FL190 with 2 persons aboard? See speaker notes for answer
Normal Procedures
• Before Starting Engine
– Brief passengers on the use of O2
– Make sure masks/cannulas are readily available in-flight
• Climb
– Don masks/cannulas prior to reaching altitudes that require O2
– Oxygen System On
– Flowmeter adjust for final cruise altitude or to maintain O2
saturation levels above 90% when using a pulse oximeter
Normal Procedures
• Cruise
– Oxygen quantity check every
20 minutes
– Oxygen pressure check every
20 minutes
– Oxygen saturation level check
every 20 minutes
Descent
– Oxygen off after descending
through altitudes that do not
require the use of oxygen
– Stow mask/cannulas
Emergency Procedures
• Cabin Fire and Smoke/Fume Elimination
– Use of O2 during a cabin fire can pose a serious threat.
– Turn O2 off and descend to an altitude that does not require the
use of oxygen
– Pilot must use good judgment and weigh the risks between use
of O2 during a cabin fire and the affects of hypoxia
• Oxygen System Malfunction
– Check flow meters for flow
– Descent below 10,000MSL or MSA
– O2 system off
Emergency Procedures
• Steady Fault Light
– Indicates a wiring
problem and the
system is disabled
– Cycle Oxygen / Cabin
Lights C/B
• Flashing Fault Light
– Indicates oxygen
pressure fault to the
distribution manifold.
– Descend to an altitude
where oxygen is not
required
Symptoms of Hypoxia
• Treat hypoxia with 100%
oxygen.
• It is a possible
emergency if no oxygen
is available and you are
hypoxic.
– Declare emergency
– Execute an immediate
emergency descent to
10,000 or MSA whichever
appropriate.
Note: the useful
consciousness time from
18,000 to 25,000
Time of Useful Consciousness
FL180
20-30 minutes
FL220
8-10 minutes
FL250
3-5 minutes
FL300
1-2 minutes
FL350
30-60 seconds
FL430
9-12 seconds
FL500 and
above
9-12 seconds
Pulse Oximeter
• Measures blood oxygen
saturation level.
• Increase the flow of O2 if
saturation levels drop
below 90%
• Descent to a lower
altitude if saturation
levels can not be kept
above 90%
Scenario
While using a cannula at 17,500MSL, you engage
in an interesting conversation with your
passengers. Shortly after, you experience
shortness of breath and notice minor cyanosis in
your finger tips. Oxygen flow is adequate.
• What is the problem?
See speaker notes for the answer