Ice Protection

Question 1

When is Cowl Anti-Ice required on the ground?

Answer 1

When OAT is +10°C or below and visible air moisture is present, or while operating on contaminated
taxiways/runways.

Question 2

When is Wing Anti-Ice required on the ground?

Answer 2

• Must be ON for Takeoff when OAT is +5°C or below and visible moisture is present, or when operating on
  contaminated runways.

Question 3

What are the conditions for in-flight icing operations?

Answer 3

Visible moisture is present at a TAT of +10°C or below, except when SAT is -40°C or below.

Question 4

What is the operation Limitation while Holding in Icing Conditions?

Answer 4

Do NOT hold in Icing Conditions with Slats Extended.

Question 5

Ice Protection is provided for which Systems?

Answer 5

• 1. Wing Leading Edges;
• 2. Engine Cowls;
• 3. Windshields & Side windows;
• 4. ADSPs (Air Data Smart Probes);
• 5. TAT Probes;
• 6. AOA sensors;
• 7. EVS window & fairing.

Question 6

When the Wing and Cowl Anti-Ice is set to AUTO, when does the system operate?

Answer 6

After 2 min from when AIS reaches 60Kt during T/O, or when the Ice Detector System detects ice at 1,500ft.

Question 7

If the Wing Anti-Ice is set to AUTO, when is the system INHIBITED on takeoff?

Answer 7

Until 2 minutes after the airspeed reaches 60 kt during takeoff or before 1,500 ft AFE.

Question 8

If there is a Failure of One of the two Wing Anti-Ice Sys, will the Wing Cross Bleed Valve automatically open?

Answer 8

Yes, if the WING XBLEED rotary switch is in AUTO.

Question 9

What is the purpose of the Wing Anti-Ice XBLEED Valve?

Answer 9

Allows both Wing Anti-Ice Systems to be supplied bleed air from a Single Engine.

Question 10

When Wing Anti-Ice is selected ON, how long it may take the EICAS to display the green WAI indications?

Answer 10

Approximately 2 minutes.

Question 11

Which Engine Bleed source is used for Cowl Anti-Ice?

Answer 11

MP (Medium Pressure) 7th Stage of the HPC (High Pressure Compressor).

Question 12

The Cowl Anti-Ice Valve (CAIV) defaults to what position?

Answer 12

it is spring-loaded OPEN. Designed to open in the event of loss of electrical power.

Question 13

Why is it recommended to remove all Pitot and AOA covers prior to starting the APU or connecting EXT AC?

Answer 13

All probe heaters are tested and powered when AC power is applied to the aircraft as part of the BIT.

Question 14

With the WING XBLEED switch in AUTO, when does the wing anti-ice Crossbleed Valve open?

Answer 14

• Engine Failure;
• Bleed source failure.

Question 15

When are the ADSP (Air Data Smart Probe) Heaters automatically tested and operated?

Answer 15

• When AC Power is initially applied All Heaters are tested and powered.
• Regulated Mode: The System turns on Automatically when 1 Engine is running or Airspeed is above 50Kt.
• Full-On Mode: Airspeeds above 65Kt.

Question 16

When does automatic application of TAT heat occur?

Answer 16

• Airplane is In flight, or
• Airspeed is above 50 kt, or
• RAT is deployed and Airspeed is above 120 kt.