11.12

Question 1

What’s clear ice

Answer 1

(Glaze ice)

Supercooled droplets that hit the surface and freeze as they flow across the surface

Smooth, hard, glossy, transparent

Question 2

What’s easier to remove rime or clear ice

Answer 2

Rime

Question 3

How’s rime ice formed

Answer 3

Water hitting a sub zero surface and instantly freezing

Question 4

What’s a characteristic of rime ice

Answer 4

Rough but lighter than clear ice

Question 5

What are visual detection indicators for pilots

Answer 5

rods outside of cockpit Windows that are built exposed to airflow so if icing conditions avail they can be seen and anti ice systems can be operated

Question 6

What’s the hot rod detector made from ans what angle is it installed at

Answer 6

Alluminium and 30

Question 7

How does a pressure operated ice detector work

Answer 7

4 holes in leading edge and 2 in the trailing edge
So in flight there’s a pressure build up in the detector and when ice forms the holes on the front will become blocked and this can cause a negative pressure which is sensed by a relay unit

Question 8

How does a pressure operated ice detector work

Answer 8

4 holes in leading edge and 2 in the trailing edge
So in flight there’s a pressure build up in the detector and when ice forms the holes on the front will become blocked and this can cause a negative pressure which is sensed by a relay unit

Question 9

What powers the rotary ice detector s

Answer 9

Single face ac motor

Question 10

How does a vibrating probe ice detector work

Answer 10

As it’s meant to vibrate at a constant frequency of 40 kHz but when ice forks this will change due to it being heavier which is the indication

Question 11

What display is the ice warning messages displayed on

Answer 11

EICAS

Question 12

What type of deicing method is used for leading edge

Answer 12

Hot Pneumatic air

Question 13

How is joined ducting sections of the wing anti ice system sealed

Answer 13

Hermetically sealed

Question 14

How are slats anti iced

Answer 14

Same systems as wing and the air is transferred to the slats via a telescopic duct

Question 15

What’s the WAI valve and what’s it do

Answer 15

Wing anti ice valve

Controls amount of air from pneumatic system to wing anti ice ducts

Question 16

How are wing anti ice valve controlled and actuated

Answer 16

Controlled- electrically

Actuated- pneumatically

Question 17

What’s used to monitor the WAI valves

Answer 17

ACIPS

Aerofoil and cowl ice protection system

Question 18

Do the WAI valves operated at same time or differential

Answer 18

Same to keep same heat on both wings

Question 19

When’s the operation of the WAI valve not allow

Answer 19

When in take off mode

When been in air for less than 10 mins

If auto mode is on

Question 20

What must windshields be able to withstand in relation to bird strike for it to be certified

Answer 20

Must be able to withstand a 2lb bird strike at cruising speed

Question 21

What’s are the two modes for electric windscreen anti ice

Answer 21

Norm- heating supplies heat to broad area of windscreen

High- supplies to more concentrated areas with a high intensity of heat

Question 22

What are wings and stabilisers using chemical anti icing system called

Answer 22

Weeping wings

Question 23

What’s a disadvantage of TKSM (chemical anti icing)

Answer 23

Can only carry a certain amount of fluid so it runs out sometimes

Question 24

What’s the most common DE-icing method for wings

Answer 24

Wing boots

Question 25

How long are de icing boots inflated for

Answer 25

6-8 sec

Question 26

What are deicing boots made of

Outside layer?

Answer 26

Rubberised fabric

Conductive neoprone (resistant to deterioration, chemical attacks, conductive)

Question 27

What do reciprocating engine ac use for de icing boot operating air

Turbine engine?

Answer 27

Engine driven pump

Bleed air

Question 28

What’s done on de icing boots on reciprocating engine to attempt to minimise disturbance to airflow

Answer 28

They are activated symmetrically but operated alternatively across the wing

Question 29

What happens when ice forms on the prop

Answer 29

Ice collects assymetricly so it is unbalanced and gashes vibration

Question 30

What type of fluid is used for chemical deicing

Answer 30

Glycol based

Isopropyl alcohol

Question 31

What’s the advantages of isopropyl alcohol being used over a glycol based chemical used for de icing

Answer 31

More available and cheaper

Question 32

What disadvantages are there of prop de ice systems

Answer 32

Heavy
Limited fluid

Question 33

How long are cycling timers on a propellor electrical deicing system

Answer 33

15-30 sec with a cycle of two mins

Question 34

What type of chemical rain repellent is used

when was irs PRODUCTION banned

Answer 34

Rain boe containing CFC113

1st jan 1996

Question 35

Does the time the push button is held for the rain repellent affect how much repellent is discharged

Answer 35

No

Question 36

Why should rain repellent only be used on a wet screen

Answer 36

Bc if it’s undiluted it can affect the visibility

Question 37

What’s the outer layer of a windscreen coated with

Answer 37

Hydrophobic coating

Question 38

What’s used to clean wind shield

Answer 38

50/50 of water and isopropanol alcohol

Question 39

What does the heated air in the pneumatic rain removal system do

Answer 39

It breaks the raindrops into small particles to be blown away
It heats the windshield to prevent the moisture from freezing

Question 40

How many wipers does the windscreen sit on

Answer 40

2

Question 41

How cycles per min do the windscreen wipes do in low speed

High?

Answer 41

160 cycle per min

250 cycle per min