Study Guide ICE Protection Flashcards
What sources are used for aircraft anti-icing and de-icing?
- Bleed air
- Electric heat
What uses bleed air for ice protection?
- Engine lips
- 3 Outboard slats
What uses electric heat for ice protection?
- Pitot-static system
- Wind shields
- 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 ice 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 the 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
- Wind shields
- Water & 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, the 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 anti-icing operations?
10th High Stage Valve (HSV)
How is bleed air directed for pneumatic anti-ice?
- Engines 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 condition 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 its wheel speed
-
If ‘ALL’ is selected on the ground, at what point will the anti-ice system become automatic?
1700’ AGL or 5 minutes after takeoff (whichever happens first)
If ‘OFF’ 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)
How does the failure of one of the two power sources affect the windshield heating system?
- On ground inhibited
- In Flight 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 for 8 seconds
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 the anti-ice system?
Yes, but it’s a maintenance function
How should the aircraft be configured for de-icing?
- Bleeds off
- Stab Trim full nose down
- Flaps up
- Engine and APU ON or OFF