1/18/23 ANTI-ICE, RAIN SYSTEM Flashcards
Which Flight Deck windows are heated?
Window 1 and Window 2
What happens if an overheat condition is detected in a heated window?
The OVERHEAT light illuminates as well as the ANTI-ICE and MASTER CAUTION lights. The controller will remove power to the window.
OVERHEAT (amber) light, when illuminated, indicates an overheat condition (62°C) for the respective window. The illumination of the OVERHEAT light illuminates the ANTI-ICE annunciator and MASTER CAUTION lights. The controller will remove power to the window if an overheat condition is detected. An overheat cannot be reset until the window cools sufficiently (approximately 2-5 minutes) and is reset by placing the respective WINDOW HEAT switch to OFF, then ON. An OVERHEAT light(s) will also illuminate if electrical power to the window(s) is interrupted.
What does the Engine Anti-Ice System protect from icing?
The engine cowl lip.
Engine bleed air thermal anti-icing prevents the formation of ice on the engine cowl lip. Engine Anti-Ice System uses 5th and 9th stage engine bleed air off the respective engine.
How does Engine Anti-Ice affect stall speed and engine thrust?
Both stall speed and engine idle thrust are increased with Engine Anti-Ice selected.
Stall warning logic adjusts Stick Shaker and minimum maneuver speed bars on the airspeed indicator. FMC displayed VREF is not adjusted automatically. Stall warning logic, airspeed indications, and minimum maneuver speeds on the airspeed indicator return to normal when Engine Anti-Ice is positioned OFF if Wing Anti-Ice has not been used in flight.
Icing idle is required to meet the bleed demand of the Engine Anti-Ice System. Icing idle is selected in flight if all of the following are present:
- flaps are fully retracted
- main gear is not down and locked, and
- engine anti-ice is selected on
When in the Icing Mode, the EEC begins transition from flight minimum idle at 30,400 ft and increases idle in the descent to provide full icing idle at and below 22,000 ft. Icing idle is required to meet the bleed demand of the engine anti ice system.
What does a COWL ANTI-ICE (amber) light indicate?
excessive pressure (greater than 65 psi) in the duct leading from the Cowl Anti-Ice Valve to the cowl lip. The ANTI-ICE annunciator and MASTER CAUTION lights will also illuminate.
What does a COWL VALVE OPEN bright blue light indicate?
• bright blue when the related Cowl Anti-Ice Valve is in transit or disagrees with the ENG ANTI-ICE switch position
• dim blue when the valve is open with the switch ON
The light is extinguished when the valve is closed and the switch is OFF
What does a green TAI (Thermal Anti-Ice) above the N1 readout indicate?
Cowl Anti-Ice Valve is open
• green when the switch is ON and the Anti-Ice Valve is open
What does an amber TAI (Thermal Anti-Ice) above the N1 readout indicate?
Cowl Anti-Ice Valve is not in the selected position.
amber when the Cowl Anti-Ice Valve fails to move to the position selected by the ENG ANTI-ICE switch
What does the Wing Anti-Ice System protect from icing?
The three inboard leading edge slats by using bleed air.
The Wing Anti-Ice System does not include the leading edge flaps or the outermost leading edge slat on each wing.
What is the difference between a dim blue and bright blue Wing Anti-Ice VALVE OPEN light?
Bright blue = Wing Anti-Ice Valve is in transit or valve position disagrees with WING ANTI-ICE switch position
Dim blue = the valve is open with the switch ON
What would cause the Wing Anti-Ice valves to close automatically if selected ON while on the ground?
Thrust levers advanced for takeoff.
Overtempertature is sensed
On the ground. With thrust levers advanced for takeoff and the Wing Anti-Ice System operating, the Wing Anti-Ice Control Valves are automatically commanded closed and the solenoid controlled WING ANTI-ICE switch will automatically release to the OFF position when air/ground sensing transitions to the air mode.
A Temperature Sensor (125°C) is installed in each Wing Anti-Ice System duct and either sensor automatically closes both Wing Anti-Ice Control Valves if an overtemperature is sensed while air/ground sensing is in the ground mode.
How does the Wing Anti-Ice system operate if selected ON for takeoff?
The Valves will be open if temperature inside both wing distribution ducts is less than the thermal switch activation temperature (125°C)
the Wing Anti-Ice valves will close when either engine’s thrust lever is advanced to the takeoff power position.
The WING ANTI-ICE switch automatically trips OFF at lift-off when the Air/Ground Sensor goes to the air mode.
How is aircraft stall protection logic affected when using Wing Anti-Ice?
Stick Shaker and minimum maneuver speed bars on airspeed indications are adjusted and remains set for icing conditions for the remainder of the flight.
Stall warning logic adjusts Stick Shaker and minimum maneuver speed bars on airspeed indications. FMC displayed VREF is not adjusted automatically. Stall warning logic remains set for icing conditions for the remainder of the flight, regardless of subsequent WING ANTI-ICE switch position.
Which external probes, vanes, ports, antennas, etc. are electrically heated by the Probe Heat system?
CAPT PITOT, F/O PITOT, L ELEV PITOT, R ELEV PITOT, L ALPHA VANE, R ALPHA VANE, TEMP PROBE, AUX PITOT
