Anti ice/ heat

Question 1

What happens when you turn the nacelle anti-ice switches on? 


Answer 1

the nacelle anti-icing valve opens when engine bleed air pressure is available

* the engine igniters selected by the Auto Ignition selector and the EEC operate continuously

* the engine bleed PRV opens when the nacelle anti-icing valve is open, unless the PRV is closed by:

- a prior or present bleed air overheat, or

- the start valve not closed, or

- the engine bleed HP valve failed open

Question 2

What conditions would prevent the PRV from opening when nacelle anti-ice is on?

Answer 2

a prior or present bleed air overheat, or

- the start valve not closed, or

- the engine bleed HP valve failed open

Question 3

With the Nacelle Anti-Ice Switches in AUTO during icing conditions, while on the ground, prior to takeoff, would the system be on or off?

Answer 3

Off - The AUTO function is for in-flight
On ground in icing conditions, the switches should be ON

Question 4

If in the NAI AUTO position, with the anti-ice valves open at touchdown, when do the valves close?

Answer 4

when air/ground system detects main gears on ground (as AUTO is an in-flight function)

Question 5

How many ice detection probes are there, and where are they located?

Answer 5

2 probes on forward fuselage

Question 6

If the engine bleed air valve is closed and nacelle anti-ice is commanded, what is the source of bleed air nacelle anti-ice?

Answer 6

IP bleed air (as HP valve closed when eng bleed valve is closed)

Question 7

Is wing anti-ice effective with the leading edge flaps extended?

Answer 7

No

Question 8

Can you operate the wing anti-ice system on the ground?

Answer 8

No

Question 9

What part of the engine and wing are heated with NAI and WAI?

Answer 9

NAI - Engine Nacelle
WAI - wing leading edges

Question 10

What is displayed on primary EICAS when the nacelle anti-ice and/or the wing anti-ice valve is open?

Answer 10

NAI/WAI by N1 indications

Question 11

Describe the flight deck window heating systems.

Answer 11

forward window outside surfaces heated by controlled high voltage power for anti-icing

all flight deck windows have anti-fogging

Question 12

Which windows’ heating system is controlled by the window heat switches?

Answer 12

forward windshield outer surface (flight deck)

Question 13

Since the forward windshields are controlled by the window heat switches, how are the side windows heated?

Answer 13

windshield air switches on aux panels control anti-fogging

Question 14

How many pitot-static probes are provided and when are they heated?

Answer 14

4 - heated when any engine is operating