Anti- Ice / Rain *** 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 left and right
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; and “WAI” for wing anti-ice.
Describe flight deck window heating systems.
- Flight deck windows are electrically heated
- Forward windshields have anti-ice protection on the exterior surfaces
- Forward windshields have anti-fogging on the interior surfaces.
- Side windows have controlled anti-fogging heating on the 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?
• 4 pitot-static probes, electrically heated when any engine is operating.
How many angles of attack probes are provided, and when are they heated?
• 2 angle of attack probes are heated when any engine is operating.
NAI: AUTO (On Ground)
System OFF. When NAI valve is open following a landing, it remains on until engine shutdown.
NAI: AUTO (In Flight)
NAI operates in response to ice detection.
NAI: ON
- Valve Opens
- Ignitors operate continuously
- PRV opens
3 times PRV won’t open for NAI activation?
- Bleed Air Overheat
- Start Valve not closed
- HP bleed valve failed open
WAI: AUTO (In Flight)
Open valves in flight with ice detection if:
- Leading edge flaps retracted
WAI: AUTO (On Ground)
Inhibited
WAI: ON (On Ground)
Inhibited
WAI: ON (In Flight)
Valves OPEN regardless of leading flap position but only effective if flaps are retracted.
WAI Valve Light (Amber)
Either WAI valve position disagrees with switch position.
NAI Valve Light (Amber)
Respective NAI valve position disagrees with switch position.
What happens if fault or overheat of fwd/side window heat occurs?
Power is disconnected
INOP Light on Switch
How do you reset system after a fault/overheat of window heat?
Push window heat switch to turn OFF for 10 seconds, then back ON.
Where is windshield washer reservoir?
Behind door in book storage of captain side panel.
When are anti-ice probes (AOA, Pitot/Static/TAT) heated?
- When any engine is running.
- TAT on in flight.
When is the TAT probe heated?
In flight only
How do we turn on the pitot heat?
They are on automatically anytime any engine is operating.
What is powered with the Window Heat switches ON? What is de-powered with the switched OFF?
ON: Controlled Heat is applied to the windshield.
*Only the front two windows are heated for anti-ice (exterior) and anti-fog (interior). 1L an 1R
Side windows are constantly heated and has anti-fog (interior).
Heat to side windows is automatic whenever AC power is on the airplane. Side window heat has no cockpit control.
OFF: Off for 10 seconds resets a heat controller fault
What does the INOP light in the Window Heat switch mean?
The switch is off, or
An overheat has occurred, or
A system fault has occurred.
What do the Washer switches do in the ON position?
Washer Fluid is applied to the respective windshield. The switch is spring loaded to the neutral position.
What do the OFF, LO, and HI positions of the Wiper switches do?
OFF: Off and sequence to the stowed position.
LO: Operates at low speed
HI: Operates at high speed
What does the Wing Anti-Ice switch do when pressed IN/OUT?
Out=OFF: Wing Anti-Ice valve commanded closed
IN=ON: In flight WAI valve opens to supply bleed air to leading edges of wing
**On ground: system is OFF and WAI valves closed regardless of position of switch.
What do the OFF, AUTO, and ON positions of the Nacelle Anti-Ice Switches do?
OFF: NAI valve commanded closed
AUTO: In flight the system operates when nacelle icing conditions exist and the ON position requirements are met.
ON:NAI valve opens when bleed pressure is available and PRV is open. . .
. . . PRV may be closed due to current or prior bleed duct overheat, starter valve not closed, or engine High Pressure bleed valve stuck open.
ON: Selected engine ignitors operate continuously
**System works on the ground or in flight in the ON position.
