Ice Protection/Detection Flashcards
What uses bleed air for ice protection?
Engine lips
3 outboard slats
What uses electric heat for ice protection?
Pitot-static system
Windshields
Water lines
Pressurization static port
If an engine fails does the opposite wing and engine receive ice protection?
Yes. The crossbleed valve opens to provide symmetrical ice protection for both wings
The failed engine does not receive heat to the engine lip
How many ice detectors must be working to have icing detection?
One. There are two for redundancy
How long will the de-icing system remain on after icing is no longer detected?
5 minutes
If ICING on MCDU is set to OFF and on takeoff roll icing conditions are encountered, will the de-icing system turn on?
Not until 1700 ft or 2 minutes after takeoff (whichever happens first)
Can the APU be used to provide bleed air for de-icing?
No
What is protected from ice & rain?
Engine inlets Wing leading edge Smart probes Windshields Water and waste drain systems
Is the ice protection system automatic?
Yes, under normal conditions
Can the pilot override the automatic system?
Yes
How is ice detected in flight?
2 ice detectors:
Vibrating sensor element that changes frequency when ice builds up around it
Once ice is detected, the sensor element heats, ice melts, the normal vibrating characteristics are restored, and the heating process stops. The cycle repeats as ice rebuilds on the probes.
What compressor stage is bleed air tapped for any-icing operations?
10th High Stage Valve (HSV)
How is bleed air directed for pneumatic anti-ice?
Engine…….independent
Wings……..onside bleed
What happens if there is a single bleed source failure?
The crossbreed automatically opens
How should the MCDU be set if there are icing conditions present on the ground?
ALL
What does selecting ALL on the MCDU provide?
Engine anti-ice……..ON when engines are running
Wing anti-ice………..ON at 40 kts wheel speed
If ALL is selected on the ground, at what point will the anti-ice system become automatic?
1700’ AGL or 2 minutes after takeoff (whichever happens first)
If OFF is selected on the ground, at what point will the anti-ice system become automated?
1700’ AGL or 2 minutes after takeoff (whichever happens first)
How does the failure of one of the two power sources affect the windshield heating system?
On the ground it is inhibited
In flight the left side is heated (right heats if left has failed)
What does the TIMER selection on the windshield wiper switch do?
Activates the associated wiper in 8-second intervals
What happens if the wiper is operated on a dry windshield?
The wiper will stop
To reset wiper move switch to OFF
When do the smart probes heat?
When an engine is running
Is there a test for anti-ice system?
Yes, but maintenence performs this test
How should the aircraft be configured for de-icing?
Bleeds…….OFF
Stab trim…….full nose down
Flaps…….up
Engines and APU……ON or OFF
What sources use for aircraft anti-icing and de-icing?
Bleed air heat
Electric heat
What surfaces are not protected by anti-ice system?
Vertical stabilizer
Horizontal stabilizer
Inboard slat panel
After leaving icing conditions what message will remain on until landing and what precautions are to be taken?
Stall Prot Ice Speed message
Must use the landing speeds associated with Stall Prot Ice Speed
How many sweeps on the wipers per minute if on high?low?
High: 120/minute
Low: 80/minute
