airframe systems nmgyjt6rtyb hgutu6t67t7 gyututu6t6rtjhyyujt jyutyut jytyu5t uytu7t68u yuyu7t678 jytyyt iuyti76t hihuyiuy7t7iy yut786t5m 77ut y7iyt67 yi76ti7i t7tu uityuiy m7tyi7 iu6yu76uiy ytiuyt yityut uyuiym uyiyiuy yutiyu yutut ytyut juytuymm ytyut ujyty ytyu hytiuyt ytyut htyjug ytyut ytyi gtyjgj jhhgtyit m, m gjyhgtyut ytyutmn hthj uytjh ghuy bhjgym

2. OXYGEN SYSTEM
Presented By
Mohsin Sabir
Hassan Sagheer

3. INTRODUCTION
 Oxygen is very impotent for human body for breathing. A lack of oxygen causes a
person to experience a condition called Hypoxia.
 As the altitude increases, the consequent decrease in pressure reduces the amount
of oxygen the human body can absorb when breathing.
 In atmosphere oxygen level is about 21 % but if altitude increase oxygen level is
decreases because of density of air is decrease.
 To enable flight at high altitudes either the aircraft cabin has to be pressurized, to
replicate the pressure at a lower altitude, or the occupants of the aircraft have to be
given supplemental oxygen. This system is known as oxygen system.

4. ATMOSPHERE

5. SOURCES OF SUPPLEMENTAL OXYGEN
Basically three types of oxygen we used in aircraft oxygen
system:
 Gaseous Oxygen
 Liquid Oxygen (LOX)
 Solid Oxygen

6. Gaseous Oxygen
 Oxygen is a colorless, odorless, and tasteless gas at normal atmospheric
temperatures and pressures. It transforms into a liquid at –183 °C.
 Oxygen combines readily with most elements and numerous compounds. This
combining is called oxidation. Typically, oxidation produces heat.
 Pure gaseous oxygen, is stored and transported in high-pressure cylinders that are
typically painted green.
 Most of the aircraft in the general aviation fleet use gaseous oxygen stored in steel
cylinders under a pressure of between 1,800 and 2,400 psi.
 It does have all the disadvantages of dealing with high-pressure gases, and there is
a weight penalty because of the heavy storage cylinders.

7. LIQUID OXYGEN
 Liquid oxygen (LOX) is a pale Blue, transparent liquid.
 Oxygen can be made liquid by lowering the temperature to below –183 °C or by
placing gaseous oxygen under pressure.
 A combination of these is accomplished with a Dewar bottle. This special container
is used to store and transport liquid oxygen.
 It uses an evacuated, double-walled insulation design to keep the liquid oxygen
under pressure at a very low temperature.
 A small quantity of LOX can be converted to an enormous amount of gaseous
oxygen, resulting in the use of very little storage space compared to that needed
for high-pressure gaseous oxygen cylinders.
 However, the difficulty of handling LOX, and the expense of doing so, has resulted
in the container system used for gaseous oxygen to proliferate throughout civilian
aviation. LOX is used nearly exclusively in military aviation.

8. SOLID OXYGEN
 Sodium chlorate has a unique characteristic. When ignited, it produces
oxygen as it burns. This can be filtered and delivered through a hose to a
mask that can be worn and breathed directly by the user.
 Solid oxygen candles, as they are called, are formed chunks of sodium
chlorate wrapped inside insulated stainless steel housings to control the
heat produced when activated.
 The chemical oxygen supply is often ignited by a spring-loaded firing pin
that when pulled, releases a hammer that smashes a cap creating a spark
to light the candle.

9. SOLID OXYGEN
 They are one-third as heavy as gaseous oxygen systems that use heavy
storage tanks for the same quantity of oxygen available.
 Sodium chlorate chemical oxygen generators also have a long shelf life,
making them perfect as a standby form of oxygen.
 They are inert below 400 °F and can remain stored with little maintenance
or inspection until needed, or until their expiration date is reached.

10. MECHANICALLY SEPARATED OXYGEN
 A new procedure for producing oxygen is its extraction from the air by a
mechanical separation process.
 Air is drawn through a patented material called a molecular sieve.
 As it passes through, the nitrogen and other gases are trapped in the sieve
and only the oxygen passes through.
 Part of the oxygen is breathed, and the rest is used to purge the nitrogen
from the sieve and prepare it for another cycle of filtering.

11. REGULATORS
 Regulators for the pressure and flow of oxygen are incorporated in stored-gas
systems because the oxygen is stored in high-pressure cylinders under pressures of
1800 psig or more.
 The high pressure must be reduced to a value suitable for application directly to a
mask or to a breathing regulator. This lower pressure is usually in the range of 40 to
75 psig, depending upon the system.
 There are two basic types of regulators in use, and each type has variations.
 Continuous flow regulators
 Demand/diluter demand regulators

12. Continuous-Flow Systems
 In its simplest form, a continuous-flow oxygen system allows oxygen to exit the
storage tank through a valve and passes it through a regulator/reducer attached to
the top of the tank. The flow of high-pressure oxygen passes through a section of
the regulator that reduces the pressure of the oxygen, which is then fed into a hose
attached to a mask worn by the user. Once the valve is opened, the flow of oxygen
is continuous.
 A manual continuous flow oxygen system may have a regulator that is adjusted by
the pilot as altitude varies. By turning the knob, the left gauge can be made to
match the flight altitude thus increasing and decreasing flow as altitude changes.
 These regulators can be manual or automatic in design.
 Continuous-flow oxygen masks are simple devices made to direct flow to the nose
and mouth of the wearer. They fit snugly but are not air tight. Vent holes allow
cabin air to mix with the oxygen and provide escape for exhalation.

13. Demand-Flow Systems
 When the individual using the equipment inhales, he or she causes a
reduction of pressure in a chamber in the regulator. This reduction in
pressure activates the oxygen valve and supplies oxygen to the mask.
 A flow indicator shows when oxygen flow is taking place. The diluter
demand regulator automatically adjusts the percentage of oxygen and air
supplied to the mask in accordance with altitude.
 The demand masks cover most of the user's face and create an airtight
seal. This is why a low pressure is created when the user inhales.

14. Demand-Flow Systems
 A diluter demand regulator dilutes the oxygen supplied to the mask with air from
the cabin. This air enters the regulator through the inlet air valve and passes
around the air-metering valve.
 At low altitude, the air inlet passage is open and the passage to the oxygen
demand valve is restricted so the user gets mostly air from the cabin.
 As the aircraft goes up in altitude, the barometric control bellows expands and
opens the oxygen passage while closing off the air passage.
 At an altitude of around 34,000 feet, the air passage is completely closed off, and
every time the user inhales, pure oxygen is metered to the mask.

15. Pressure Demand Regulators
 Operate in much the same way as diluter demand regulators except at extremely
high altitudes, where the oxygen is forced into the mask under a positive pressure.
 Breathing at this high altitude requires a different technique from that required in
breathing normally.
 The oxygen flows into the lungs without effort on the part of the user, but muscular
effort is needed to force the used air out of the lungs.
 This type of equipment is normally used at altitudes above 40000 ft [13632 m].
 The additional pressure is needed to enable the user to absorb oxygen at a greater
rate than it would be absorbed at ambient pressure. A pressure demand mask must
be worn with a pressure demand regulator.

16. THANK YOU