11.12

Question 1

Whats the 3 most common types of ice encountered during flight ?

Answer 1

Clear ice
Rime ice
Mixed ice

Question 2

Explain clear ice ?

Answer 2

-Formed by large supercooled water droplets which gradually freeze as they flow across the surface leaving hard, glossy covering of ice over the wing surface.

-heavy and clings to surface.

Question 3

Explain rime ice ?

Answer 3

-Formed from small supercooled water droplets

-identified as a white colour

-lighter than clear ice

Question 4

Explain mixed ice ?

Answer 4

Mix of clear and rime ice properties.

Question 5

Whats the two types of visual detection for icing ?

Answer 5

Wing inspection lights
Visual ice indicators

Question 6

Explain wing inspection lights ?

Answer 6

Located on each side of the fuselage forward section facing the leading edge which allows flight crew to inspect the leading edge and detect any ice in low ambient light conditions.

Question 7

Explain visual ice indicators ?

Answer 7

Posts which are located in between the windscreen in the pilots view which collects ice from the airflow allowing them to detect icy conditions and turn on the anti-ice systems.

Question 8

Explain the hot rod detector ?

Answer 8

Rod located outside the window in the pilots veiw which builds up ice in cold conditions and has the ability to be de-iced.

Question 9

Explain a pressure operated ice detector ?

Answer 9

4 holes drilled into leading edge and 2 hole in tailing edge which when a build up of ice on the wing blocks theses hole, the detector senses the pressure difference by a relay unit which closes and triggers a ice warning in the flight deck and automatically activates a heating element to melt the ice.

Question 10

Explain a rotary ice detector ?

Answer 10

Mounted on forward fuselage which has has rotating rotors which constantly spin with little required torque in normal conditions but in icy conditions it requires greater rotational torque which causes motor to rotate slightly which operates a micro switch which gives a ice warning.

Question 11

Explain a vibrating probe ice detector ?

Answer 11

Probe vibrates at a set frequency which when in contact with ice causes the frequency to decrease. Detector sensor tiggers a crew advisory or automatic system to activate ice protection systems.

Question 12

Whats the three certification types of ice detectors ?

Answer 12

Primary automatic
Primary manual
Advisory

Question 13

Explain primary automatic ice detectors ?

Answer 13

System automatically activates aircraft ice protection systems when needed by using signals from the ice detector.

Question 14

Explain primary manual ice detectors ?

Answer 14

Alerts the crew when protection is required which they will then activate the ice protection manually.

Question 15

Explain the advisory ice detector ?

Answer 15

Alerts crew with advisory’s requiring them to activate ice protection systems when conditions are favourable.

Question 16

Explain the process of thermal pneumatic ani-icing ?

Answer 16

Prevents ice on leading edges

Warm air enters duct which travels along the leading edge and exits through holes, allowing air to be distributed around the the inner surface of the aerofoil

( wing anti-ice system )

Question 17

Explain the process of a wing anti-ice system ?

Answer 17

Utilise hot air which can be bled off from the engine compressors to provide the anti-icing heat. Hot air is routed through ducting manifolds and valves to the leading edge of the wing.

Question 18

What happens to the anti-icing systems to the leading edge if the aircraft has slats ?

Answer 18

The hot air is now routed to inside the slat from the leading edge of the wing.

Question 19

Explain the function of a wing anti-ice valve ?

Answer 19

Controls the flow of bleed air from the pneumatic system to the wing anti-ice ducts.

Question 20

Explain the function of a wing anti-ice valve pressure sensor ?

Answer 20

Detects the air pressure in the wing anti-ice ( WAI ) duct when the WAI valve opens

Question 21

Explain the function of the Wing anti-ice duct ?

Answer 21

Moves in from the pneumatic system, through the wing LE, to the LE slats

Question 22

What information is shown to the pilot when monitoring the wing anti-ice system ?

Answer 22

Wing manifold pressure
Valve
Air pressure
Air flow

Question 23

Explain the function of the engine anti-ice system ?

Answer 23

Bleed air from the engine is ducted to the LE of the engine inlet cowls. Then exits through vents.
( usually automatically activated )

Question 24

What are aircraft windshields usually made from ?

Answer 24

Laminated glass.
( laminations create impact resistance )

Question 25

Where are the heating elements installed in an aircraft’s windshield ?

Answer 25

Inner layer of the most outer pane

Question 26

Whats the two windshield heating levels ?

Answer 26

Normal - heats the broadest area of windshield

High - higher intensity of heat to smaller, more specific areas of the window.

Question 27

Whats the trade name of chemical anti-icing system ?

Answer 27

TKS

Question 28

Where does the chemical anti-icing system target ?

Answer 28

LE of wings
Stabilisers
Windshields
Propellers

Question 29

Explain the process of the chemical anti-icing system ?

Answer 29

Solution pumped from reservoir through mesh screen on the LE of wings. Activate a switch and the liquid flows over the wing and tail surfaces preventing ice formation as it flows.

Question 30

Explain the pneumatic de-icing boots on a panes wing ?

Answer 30

Inflatable boots expand by pneumatic air pressure breaking away any ice built up on them.
( deflated by suction )

Question 31

In a reciprocating engine aircraft, Whats the source of pneumatic air for a de-ice bot system ?

Answer 31

Engine - driven air pump

Question 32

In a turbine engine aircraft, what is the source of pneumatic air for a de-icing boot system ?

Answer 32

Bleed air from engine compressor.

Question 33

On a turboprop airplane, Why is de-ice boots installed in sections along the wing length ?

Answer 33

To minimise disturbance to airflow, cause by inflated tube by inflating only short sections on each wing at a time.

Question 34

Whats the source for pneumatic air on a turboprop aircraft to operate the de-ice boots ?

Answer 34

Engine bleed air.
( after certain amount of time inflated, electronic timer switches the distributor in control assembly to deflate wing boot )

Question 35

How can a de-ice boots life be extended ?

Answer 35

By storing them when they are not needed.

Question 36

Explain an electric de-ice boots ?

Answer 36

Contains electrical heating elements.

When activated, the boot heats up and melts ice.

Question 37

Whats the 3 rain control systems ?

Answer 37

Chemical rain repellant
Pneumatic rain removal
Coating windshield

Question 38

Explain the chemical rain repellent ?

Answer 38

Forms a film that changes way the water behaves on contact.

( shouldn’t be applied to dry windshield )

Question 39

Explain windshield surface coating ?

Answer 39

Causes raindrops to bead up and roll off

( coating penetrates the windshield providing long-term action. )

Question 40

Explain pneumatic rain removal system ?

Answer 40

Removes rain by directing a flow of heated air over windshield.

Question 41

What two functions does a pneumatic rain removal system provide ?

Answer 41

Breaks rain drops and blows away

Heats windshield preventing moisture from freezing

Question 42

Explain water and drain anti-ice ?

Answer 42

Electrical heaters wrapped around water lines to prevent ice build up inside.