Ice Protection / Detection Questions

Question 1

What sources are used for aircraft anti-ice 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 no longer detected?

Answer 6

• 2 Minutes

Question 7

If icing on the MCDU is set OFF and on takeoff roll icing conditions are encountered, will the de-icing system turn on?

Answer 7

• Not until 1700 ft or 2 minutes after takeoff (whichever happens first)

Question 8

Can the APU be used to provide bleed air for de-icing?

Answer 8

• NO

Question 9

What is protected from ice & rain?

Answer 9

• Engine inlets
• Wing leading edge
• Smart probes
• Windshields
• Water & waste drain system

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 that changes frequency when ice builds up around it
• Once ice is detected, the sensor element heats, the ice mets, 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-ice 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

• Crossbleed automatically opens

Question 16

How should the MCDU be set if there are icing conditions 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 elected on the ground at what point will the anti-ice system become automatic?

Answer 18

• 1700 AGL or 2 minutes 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 minutes after takeoff (whichever happens first)

Question 20

How does the failure of one of the two power source 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 seconds 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 an 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 - Engine and APU ON or OFF

Question 26

When should ENG heat be selected on in the DATASET MENU?

Answer 26

When OAT is between 5 and 10 and when there is a possibility of encountering visible moisture up to 1700 ft