ICE AND RAIN Flashcards
Is automatic ice detection available on the ground?
No, only in flight
Is Engine anti-ice available during Engine out taxi?
Yes, but only on the operating Engine. No cross feed of air for Engine anti-ice
Where is EAI indicated when in operation?
Next to N1 levels on primary EICAS display
Is Wing anti-ice available on the ground?
No
List the inhibits for wing anti-ice
- No WAI on gnd.
- Inhibited for 5 min after liftoff if TAT is +10 deg or more regardless of switch position (ON or AUTO)
- AUTO inhibited for 10 min with T/O thrust or until the engines comes out of THR REF to CLB.
Where is wing anti-ice indicated during operation?
Between N1 and EGT indications on primary EICAS
Is wing anti-ice available for the other wing after one wing anti-ice valve fails closed?
No, the other valve closes to prevent assymetric ice pick-up
Which windows have anti-ice protection?
The 2 main FWD windows
How many wiper speeds are there and what are the cycles/min for each one of them?
3
INT: 1 cycle every 7 seconds
LOW: 160 cycles/min
HIGH: 250 cycles/min
Are the pitot and TAT probes constantly heated?
No
Pitot: When either engine is running
TAT: In flight
How many pitot probes are there?
3
How many Angle Of Attack (AOA) probes are there and how are they heated?
2
They are electrically heated
How many ice detectors are there on the B777?
2
What is the general principle of operation of the ice detectors?
They vibrate at approx 40’000 Hz and ice formation will make them vibrate at a lower frequency. Below a certain frequency (39’867Hz) the heater turns on and melts the ice. Should take about 5-7 seconds to melt the ice. If heater is on for more than 25 sec it is turned off and a fault condition is registered.
The detector has control logic that counts the number of heating cycles.
How many heating cycles is needed to start EAI?
2 cycles
How many heating cycles is needed to start the WAI?
10 cycles
How long will the ice detector system function after it has been starting sending signals to the ACIPS (Airfoil and Cowl Ice Protection System)?
Signal will be on until
- No ice is detected for 3 min
- The airplane is on the ground
- The heater is on for more than 15 sec
How many slats per wing are heated by wing anti-ice?
3 per wing
Left wing: 3,4,5
Right wing: 10, 11, 12
What can be a visual indication of light icing?
Under the windshield wipers is one of the first places where icing will form. Precipitation falls on the bottom of the windshield and runs up the wipers.
What can be a visual indication of moderate icing and possibly airframe icing?
If it forms on the protruding parts of the windshield wipers that is a good indication that icing is probably present on other parts of the airframe
What can be a visual indication of severe icing?
If ice forms on a flat heated windshield that indicates severe icing.
What does the EICAS message “ICE DETECTORS” mean and what is your action?
EICAS “ICE DETECTORS” advisory message means that automatic ice detection and alerting has failed. Set Anti-ice switches to ON to ensure proper anti-icing functionality in icing conditions.
