Anti-Ice/Window Heat - Question Bank Flashcards
What happens when you turn the nacelle anti-ice switches on?
• NAI valve opens when the bleed air pressure is available.
• Engine igniters selected by the Auto Ignition selector and EEC operate
continuously.
• PRV opens when anti-ice is ON.
What conditions would prevent the PRV from opening when nacelle anti-ice is
on?
- Prior or present bleed air overheat
- Start valve not closed
- HP bleed air valve failed open
With the Nacelle Anti-Ice Switches in AUTO during icing conditions inflight,
when will the system operate?
When nacelle icing conditions exist
When a Nacelle Anti-ice switch is ON, the respective nacelle anti-icing valve is:
Commanded open
How many ice detection probes are there, and where are they located?
Two probes are located on the forward fuselage
If the engine bleed air valve is closed, and nacelle anti-ice is commanded, what is the source of bleed air for nacelle anti-ice?
IP bleed only (HP bleed valve remains closed)
Is wing anti-ice effective with the leading edge flaps extended?
No, wing anti-ice is ineffective when the LEF are not retracted.
Can you operate the wing anti–ice system on the ground?
No, on the ground, the system is off and the wing anti-ice valves are closed
What part of the engine and wing are heated with NAI and WAI?
- Nacelle inlets
- Wing leading edges
What is displayed on primary EICAS when the nacelle anti-ice and/or the wing anti-ice valve is open?
- “NAI” for nacelle anti-ice
- “WAI” for wing anti-ice
Describe the flight deck window heating systems
- Flight deck windows are electrically heated
- Forward windshields have anti-ice protection on exterior surfaces
- Forward windshields have anti-fogging on the interior surfaces
- Side windows have controlled anti-fogging heating on their interior surfaces
What windows’ heating system is controlled by the window heat switches?
Forward windshields only
Since the forward windshields are controlled by the window heat switches, how do we heat the side windows?
- Side window heating is automatic
- No flight deck controls are provided
- System is powered whenever the AC electrical system is powered
How many pitot-static probes are provided, and when are they heated?
-4x pitot-static probes, electrically heated when any engine is operating
How many angle of attack probes are provided, and when are they heated?
-2x angle of attack probes are heated when any engine is operating
