EASA Part 66 Module 11.12 and 13.9 Ice & Rain Protection Powerpoint Slides

1. AIRCRAFT
ENVIRONMENTAL
SYSTEMS
Aircraft Ice & Rain Protection

2. AGENDA
EFFECTS OF ICE ACCRETION
TYPES OF ICE
METHODS OF OVERCOMING
ICING

3. INTRODUCTION
Aircraft must be able to fly in condition that could
produce ice accretion.
The formation of ice on the aircraft
Airframe icing => loss of aircraft performance =>
higher fuel consumption => difficulty in aircraft
control
ice form when:
• water in liquid state
• ambient air is below 0°C

4. BUILD UP OF ICE
A supercooled water droplet is a droplet
of water still in liquid state although
temperature is below 0°C
it exist in the cloud at temp as low as -
40°C

6. EFFECTS OF ICE
ACCRETION
GROUP ACTIVITY ~ Yezzzzaaaa :)
• 4 to 5 members
• discuss WHAT are effects of ice
accretion on the aircraft. and WHY?
• 20 MINUTES
• Each group will present 1 example at
a time in rotation

7. EFFECTS OF ICE
ACCRETION
A decrease in LIFT
Increase in DRAG
Decrease in Propeller efficiency
Increase in WEIGHT, LIFT?
Blockage of PITOT STATIC, ENGINE INTAKE
Loss of Vision
Loss Control

8. ICE ACCRETION
The surface on which ice accretion occurs are
only those frontal area which face the airstream:
The leading edge of wings, tailplanes and fin.
Engine air intakes
Propellers
Windscreen
Pitot-static tubes, antenna masts and similar
small items projecting from the surface of the
aircraft.

9. TYPES OF ICE
1. Glaze Icing or Runback Icing
2. Rime Ice
3. Glime Ice
4. Dry Icing
5. Hoar Frost

10. TYPES OF ICE
another GROUP ACTIVITY~ wooohooo..
• each MEMBER of the group will get 1
type of ice
• DISCUSS and SHARE your findings
• 10 mins
Hi again!

11. TYPES OF ICE
1. Glaze Icing or Runback Icing (A)
2. Rime Ice (B)
3. Glime Ice (C)
4. Dry Icing (D)
5. Hoar Frost (E)

12. TYPES OF ICE
Glaze Icing or
Runback Icing
also known as clear ice
This ice can jam controls
transparent or translucent
coating of ice with a
glossy surface
appearance
difficult to detect (esp a
night)
water particles becomes
ice when in contact with
aircraft

13. TYPES OF ICE
Rime Ice
Supercooled water
droplets striking on
aircraft is in small
quantity
not spread on impact but
immediately froze
become a piece of ice
attached to the aircraft

14. TYPES OF ICE
Glime Ice (Mixed)
Supercooled water
droplets take longer time
to froze when in contact
cause large water particle
to accumulate when
freezing takes longer
giving an opaque shape

15. TYPES OF ICE
Dry Icing
icing does not occur on
12000 m (4000 ft)
droplets are already frozen
it wont affect the aircraft
surface
but if it accumulate in
large volume, it can affect
the engine intake auxiliary
cooling duct

16. TYPES OF ICE
Hoar Frost
occur on the surface which
is below freezing point
It forms in clear air,
water vapour being
converted directly into
ice crystals forming a
white feathery coating
needs to be de-ice
before take-off

17. OVERCOMING ICING
Two methods:
De-icing
Anti icing
The system is switched on and
off at regular intervals. During
the off period, a certain
amount of ice is allowed to
accumulate on the surface, not
enough to affect the aircraft.
The deposit is then shed by
operating the system for a
short time.
The protection system
is switched on prior to
encountering icing
conditions and is left
on so that no ice is
allowed to form on the
aircraft.

18. AEROFOIL PROTECTION
4 Primary methods used for aerofoil protection:
1. THERMAL - ducting hot air along the inner
aerofoil LE
2. ELECTRICAL - Fitting heater element to the
aerofoil LE
3. PNEUMATIC - fitting compressed air operated
overshoes to the aerofoil LE
4. FLUID - pumping a fluid having low freezing
point, from distributors to the aerofoil LE

19. AEROFOIL PROTECTION
Group Presentation:-
Divide yourself into 4 groups
Each group will have 1 Primary methods
Discuss the primary method based on:
1. How does it work?
2. how does the maintenance carried out?

20. Group Presentation
D A C B
Ijat Alya Andy Thomas
Darina Mateen Ilyas Azib
Azarya wafiq Danial Sham
Wafie
A B C D
Durra Ainul Shafiq Nicky
Atul Jalwa Gab Khayrin
Ananyot Halim Afiq Yus
Ishyra

21. PNEUMATIC DEICING
SYSTEM
Utilises a series of inflatable rubber boots on the
leading edges of the mainplanes, tailplane and
fin.
Commonly fitted to piston engined or twin turbo
propeller type aircraft. Not suitable for use on
some of the high speed aerofoils fitted to modern
jet aircraft, because of the disturbing effect that
the boots have on the airflow around the aerofoil
section.
When ice has accumulated on the leading edges
the boots are inflated and the ice is then broken
away by the swelling of the boots.
The cycle is repeated as often as possible.

23. PNEUMATIC DEICING
SYSTEM cont...
De-icer boots are made from soft, pliable rubberise
fabric, the outer ply of which is made from
Neoprene.
Neoprene is used in this position in order to
provide a resistance to abrasion and deterioration
and in order to provide an electrically conducting
path to dissipate accumulated charges of static
electricity.
The whole boot is bonded to the leading edge
using a suitable adhesive.
The edges are then sealed and coated with
conductive cement or paint to complete the

24. DE-ICER BOOTS

26. DE-ICER BOOTS

27. PNEUMATIC DEICING
SYSTEM cont...
During the operation the de-icers tubes are inflated
with pressurised air and deflated by vacuum
pressure in a particular sequence which is
controlled in most cases by an electronic timing
device.
Inflation of the boot causes any ice that has formed
on the leading edge to break off and carried away
by the airstream.

28. PNEUMATIC DEICING
SYSTEM cont...
De-icer boots are installed in sections along the
leading edge of the aerofoil.
The different section operate alternately and
symmetrically about each aerofoil.
Left and right wing outer sections would work
together and once deflated, the two inner sections
would then inflate together.
This ensures that any disturbance to the airflow
caused by air inflating parts of the boots is kept to
a minimum.

29. MAINTENANCE
PROCEDURES/PRECAUTIONS
Because of their location, the de-icer boots tend to
be vulnerable to damage caused during
operational conditions i.e. hail, dust and dirt.
Dust and dirt and other damage may be caused by
ground handling and servicing operations i.e.
refuelling hose damage and access ladders being
leant against them.

30. MAINTENANCE
PROCEDURES/PRECAUTIONS
Repair of De-icing boots
Minor damage to the boots can be repaired in site.
There are two types of material used to repair the pneumatic de-icer boots:
• The patch kit.
• The surface refurbishment coating.
Repair Limitations
Repairable damage is generally:
• Cuts and tears less than 0.75 in (19 mm) long.
• Scuff damage to an area of 4.5 x 9.5 in (114 mm x 241 mm).
Irreparable damage is generally:
• Cuts and tears longer than 0.75 in (19 mm).
• Cuts and tears which cross stitch lines or are within 0.125 in (3.2 mm) of a
stitch line.
• Broken stitches.
De-icer boots with irreparable damage must be replaced.

31. Page 53 to 68
1. READ
2. SCAN
3. WRITE
• Ice Detector (53 - 59)
• Windshield Anti - Icing (61 - 68)
S U M M A R Y W R I T I N G

32. SUMMARY
Summarize what have we learned!

33. Thank You For Your Attention!