Ice Protection/Detection

Question 1

What sources are used for aircraft anti-icing and de-icing?

Answer 1

• Bleed air heat

- Electric heat

Question 2

What uses bleed air for ice protection?

Answer 2

• Engine lips

- 3 outboard slats

Question 3

What uses electric heat for ice protection?

Answer 3

• Pitot-static system
• Windshields
• Water lines
• Pressurization static port

Question 4

If an engine fails does the opposite wing and engine receive ice protection?

Answer 4

• Yes. The crossbreed valve opens to provide symmetrical ice protection for both wings
• The failed engine does not receive heat to the engine lip

Question 5

How many ice detectors must be working to have icing detection?

Answer 5

One. There are two for redundancy

Question 6

How long will the de-icing system remain on after icing is not longer detected?

Answer 6

5 mins or mins, dependent upon which Epic load is installed on the aircraft

Question 7

If ICING on the MCDU is set to OFF and on takeoff roll icing conditions are encountered, will the deicing system turn on?

Answer 7

Not until 1700 ft or 2 mins after takeoff, whichever happens first

Question 8

Can the APU be used to provide bleed air for deicing?

Answer 8

No

Question 9

What is protected from ice and rain?

Answer 9

• Engine inlets
• Wing leading edge
• Smart probes
• Windshields
• Water and waste drain systems

Question 10

Is the ice protection system automatic?

Answer 10

Yes, under normal conditions

Question 11

Can the pilot override the automatic system?

Answer 11

Yes

Question 12

How is ice detected in flight?

Answer 12

• 2 ice detectors
• Vibrating sensor element the 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

Question 13

What compressor stage is bleed air tapped for anti-icing operations?

Answer 13

10th high stage valve (HSV)

Question 14

How is bleed air directed for pneumatic anti-ice?

Answer 14

• Engines: Independent

- Wings: Onside bleed

Question 15

What happens if there is a single bleed source failure?

Answer 15

The crossbleed opens automatically

Question 16

How should the MCDU be set if icing conditions are present on the ground?

Answer 16

ALL

Question 17

What does selecting ALL on the MCDU provide?

Answer 17

• Engine anti-ice: ON when engines are running

- Wing anti-ice: ON at 40 kts wheel speed

Question 18

If ALL is selected on the ground, at which point will the anti-ice system become automatic?

Answer 18

1700’ AGL or 2 mins after takeoff, whichever happens first

Question 19

If OFF is selected on the ground, at what point will the anti-ice system become automatic?

Answer 19

1700’ AGL or 2 mins, whichever happens first

Question 20

How does the failure of one of the two power sources affect the windshield heating system?

Answer 20

• On ground: Inhibited

- in flight: Left side is heated (right heats if left has failed)

Question 21

What does the TIMER selection on the windshield wiper switch do?

Answer 21

Activates the associated wiper in 8-second intervals

Question 22

What happens if the wiper is operated on a dry windshield?

Answer 22

• The wiper will stop

- To reset wiper move switch to OFF

Question 23

When do the smart probes heat?

Answer 23

When a engine is running

Question 24

Is there a test for the anti-ice system?

Answer 24

Yes, but maintenance performs this test

Question 25

How should the aircraft be configured for de-icing?

Answer 25

• Bleeds: OFF
• Stab trim: Full nose down
• Flaps: UP
• Engines and APU: ON or OFF