Air conditioning and icebreaking from aircrafts project presentation

1. AIR CONDITIONING, ANTI
ICING & DE-ICING IN
AIRCRAFTS
NS ASAD A. JANJUA
PC MUBASHIR SHARIF
GC HAFIZ MUDASSIR
NS DANISH IFTIKHAR
AC & REFRIGERATION PRESENTATION

2. AIR
CONDITIONING IN
AIRCRAFTS

3. PURPOSE
• Like any other air condition system to provide passengers with
comfortable air
• Pressure
• Temperature
• Humidity
• Cleanliness

4. WHERE DOES THE CONDITIONING AIR
COME FROM?
• The air source in aircraft ECS (Environmental control system) is ultimately
outside air.
• ECS take compressed air from main engines (before the combustion
chambers, instead of having dedicated compressors to pump outside air
(but B787 is based on the latter). This is known as the bleed air.
• The conditioning air temperature is obtained by mixing
• The hot source is the bleed air
• A cold air source from the heat exchangers

5. STEPS
1. Air compression
2. Cooling the compressed air

7. AIR TEMPERATURE CONTROL SYSTEM
• Can be operated
• Automatically
• Manually

8. WHY CANT WE USE THE AIR DIRECTLY?
• To keep the cabin pressurized
• It is easier to cool hot air than warm cold air.
• Temperature at high altitudes are dramatically very low.

9. PRESSURIZING THE CABIN
• Cabin pressurization is the pumping of compressed air into an aircraft
cabin to maintain a safe and comfortable environment for crew and
passengers when flying at altitude.
• Pressurization becomes necessary at altitudes beyond 10,000 feet
(3,000 m) above sea level to protect crew and passengers from the risk of
a number of physiological problems caused by the low outside air
pressure above that altitude; it also serves to generally increase
passenger comfort.
• Examples of problems, Hypoxia, Altitude sickness, Decompression
sickness

11. • The fuselage is pressurized from the front to the back of the cabin.
• Pressure and its rate is controlled by the amount of air outboard.
• The pressure can be controlled
• Automatically
• Manually by the flight crew

12. AUTOMATIC PRESSURIZATION
• Automatic pressurization controls the pressure of the cabin in accordance
with the altitude of the aircraft.
• It changes with the altitude automatically and also changes during the
ascend and the decent transition periods

13. AIRCRAFT ANTI-ICING/ DE-ICING
SYSTEMS

14. NEGATIVE EFFECTS OF ICE BUILDUP
• Destroys smooth flow of air
over wing, leading to severe
decrease in lift and increase in
drag forces
• As angle of attack is increased
to compensate for decreased
lift, more accumulation can
occur on lower wing surface
• Causes damage to external
equipment such as antennae
and can clog inlets, and cause
impact damage to fuselage and
engines
• Considered a cumulative
hazard because as ice builds
up on the wing, it increasingly
changes the flight

15. TYPES OF ICE
• Rime: “has a rough milky white appearance
and generally follows the surface closely”
• Clear/Glaze: “sometimes clear and smooth
but usually contain some air pockets that
result in a lumpy translucent appearance,
denser, harder and more difficult to break
than rime ice”

16. ICE DETECTION
• Electronic ice detection common, but can give false
readings
• After mass of probe has increased due to additional
ice, anti-icing systems are alerted and turned on
• This increases fuel efficiency and system life as de-
icing systems are only turned on as required by
conditions

17. TYPES OF ICE REMOVAL
• Anti-Icing
• Preemptive, turned on before the flight enters icing conditions
• Includes: thermal heat, prop heat, pitot heat, fuel vent heat, windshield
heat, and fluid surface de-icers
• De-Icing
• Reactive, used after there has been significant ice build up
• Includes surface de-ice equipment such as boots, weeping wing
systems, and heated wings

18. PROPELLER ANTI-ICERS
• Ice usually appears on propeller
before it forms on the wing
• Graphite electric resistance
heaters on leading edges of
blades can also be used

19. WINDSHIELD ANTI-ICERS
• Liquids used include: ethylene glycol, propylene glycol, Grade
B Isopropyl alcohol, urea, sodium acetate, potassium acetate,
sodium formate, and chloride salts
• Chemicals are often bad for the environment
• Usually uses resistance heat
to clear windshield or
chemical sprays while on the
ground

20. THERMAL HEAT
• Air Heated
• Bleed air from engine heats inlet
cowls to keep ice from forming
• Bleed air can be ducted to wings
to heat wing surface as well
• Ice can also build up within
engine, so shutoff valves need to
be incorporated in design
• Usually used to protect leading
edge slat, and engine inlet cowls
• Resistance heater
• Used to prevent ice from forming
on pitot tubes, stall vanes,
temperature probes, and drain
masts Airplane Design, Book 4, Roskam

21. BOOTS
• Inflatable rubber strips that run
along the leading edge of wing
and tail surfaces
• When inflated, they expand
knocking ice off of wing surface
• After ice has been removed,
suction is applied to boots,
returning them to the original
shape for normal flight
• Usually used on smaller planes

22. WEEPING WING
• Fluid is pumped through mesh screen
on leading edge of wing and tail
• Chemical is distributed over wing
surface, melting ice
• Can also be used on propeller blades
and windshields

23. ELECTRO-IMPULSE DEICING
• Electromagnetic coil under
the skin induces strong eddy
currents on surface
• Delivers mechanical impulses
to the surface on which ice
has formed
• Strong opposing forces
formed between coil and skin
• Resulting acceleration sheds
ice from the surface
• Can shed ice as thin as 0.05”
•http://www.idiny.com/eidi.html

24. TYPICAL ANTI-ICING
• C-130:
• Engine bleed air used for anti-icing wing and empennage leading edges,
radome, and engine inlet air ducts.
• Electrical heat provides anti-icing for propellers, windshield, and pitot
tubes.
• 777:
• Engine bleed air used to heat engine cowl inlets. If leak is detected in
Anti-Ice duct, affected engine Anti-Ice valves close.
• Wing Anti-Ice System provides bleed air to three leading edge slats on
each wing. Wing Anti-Ice is only available in flight.

25. QUESTIONS

26. THANK YOU!