Ice Detection / Protection Flashcards
What sources are used for aircraft anti-icing and de-icing?
Bleed air heat and electric heat
What uses bleed air for ice protection?
Engine lips, 3 outboard slats (2,3,4 on each wing)
What uses electric head for ice protection?
Smart probes, TAT probes, windshields, water lines, pressurization static port
If an engine fails, does the opposite wing and engine receive ice protection?
Yes. The cross bleed valve opens to provide symmetrical ice protection for both wings (the failed engine does not receive head to the engine lip)
How many ice detectors must be working to have icing detection?
One. There are 2 for redundancy
How long wil the de-icing system remain on after icing is no longer detected?
5 minutes
If ICING on the MCDU is set to OFF and takeoff roll icing conditions are encountered, will the de-icing system turn on?
Not until 1,700’ or 2 min after takeoff (whichever happens first)
Can the APU be used to provide bleed air for anti-icing?
No
What is protected from ice and rain?
Engine inlets, wing leading edge, smart probes and TAT probes, windshields, water and waste drain systems
Is the ice protection system automatic?
Yes, under normal conditions
Can a 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 heading process stops
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 cross bleed 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 40kts wheel speed
If ALL is selected on the ground, at what point will the anti-icing system become automatic? What if OFF is selected?
1,700’ AGL or 2 min after takeoff, which ever happens first, Same will occur when selected OFF
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 side has failed)