Systems -Ice and Rain Protection

Question 1

How is the overhead Ice Protection Panel laid out?

Answer 1

1) Top Row is Pneuamtically Heated AI
2) Middle Row is Electrically Heated AI
3) Bottom Row controls the pneumatic heating

Question 2

When do the sensors and probes for windshield heat start heating?

Answer 2

after engine start.

Question 3

What is required for wing and tail anti ice to activate and why?

Answer 3

At least 25 kts of speed so that they don’t warp from the intense heat from the eng. bleeds.

Question 4

Does Engine Lip Anti-Ice have any min speed requirements in order to operate?

Answer 4

No.

Question 5

If the Ice Detection Knob is in the ENG position when will you have lip anti-ice and when will you have wing/tail anti ice?

Answer 5

1) Lip Anti Ice All the time
2) Wing and Tail if:
- above 25 kts
- Ice detector detects ice.

Question 6

If the ice detection knob is in the AUTO position when will you get A/I protection?

Answer 6

1) None unless an Ice Detector Detects Ice, then
2) Get Lip Anti-Ice (no speed restriction) and
3) Wing and Tail A/I above 25 kts.

Question 7

If the Ice detection knob is in the ALL position, what kind of A/I protection do you get?

Answer 7

1) Negates the requirement for the ice detector to detect ice so you will get:
2) Lip A/I immediatly
3) WIng & Tail above 25 kts.

Question 8

Should you ever have the Ice protection knob in ALL on the ground?

Answer 8

No, except during test.

Question 9

What principle does the Ice Detection system work on?

Answer 9

Ultra Sonic Vibration

Question 10

What happens when a contaminent freezes to the Ice Detectors?

Answer 10

Changes the vibration frequency which triggers:

1) a signal to open all the ice valves to the engine lip wing and tail (valid for 1 min).
2) Probe will rapidly heat, then cool back to ambient in a matter of seconds (melts the ice, then immediatly ready to detect again).
3) Sends a signal to shut off pack #1 if #2 is working if below 24,600 feet.

Question 11

Why does the Ice Detection system shut off the #1 pack under 24,600 feet

Answer 11

1) Direct all bleed air to the tail since tail anti ice is accomplished with bleed air from engine #1.
2) Limitation for 1 pack operation is 25,000 feet.

Question 12

What is a PRSOV?

Answer 12

Pressure Regulating Shutoff Valve:

• “Smart” engine bleed valve
• Can modulate between fully open and fully closed (EBV can only be either fully open or fully closed)
• PRSOV makes use of bleed air much more efficiently.

Question 13

Where are the exit points for Wing A/I Air?

Answer 13

1) Vents/ Slots on the underside of the wing
2) Vortilons - 4 on each side on the bottom leading edge of the wings that work like vortex generators.

Question 14

Where is the exit point for the Horizontal Stab air

Answer 14

Vents near the elevator known as the “horn”

Question 15

When is the “Flight Idle” Anti Ice schedule over-ridden?

Answer 15

Below 15,000ft with gear down

Question 16

If you get a stack of Ice Warning Fail EICAS messages when you bring the TL to idle in icing conditions under 15,000’ what should you do?

Answer 16

Understand that this is a normal condition and messages should clear themselves once you increase the thrust and the A/I comes back online and the ice melts.

Question 17

How will the FADEC compensate for thrust loss feeling in case you hit icing conditions after takeoff

Answer 17

When you tell it you are doing an Iceing takeoff, it will keep some thrust in reserve and provide it at the point you hit icing and A/I detects ice.

Question 18

How is an Ice Test Conducted?

Answer 18

1) Engine Bleeds - Open
2) APU Bleed - CLosed
3) A/C Packs - On
4) Ice Detect Override - ALL
5) T.L - 83% N2
6) Ice Det Test Knob - 1 then 2 (no more than 15 secs at a time)

Check for OPEN inscription on ENG, WING & STAB buttons is displayed on each side.

Question 19

What EICAS messsages should you see after the Ice Test completes?

Answer 19

ICE - Condition

ICE - detect fail

BABY - Bleed low temp

CROSS BLEED MAYBE - May or may not have an X-Bleed open message.

Question 20

Should you ever reset or alternate a FADEC after an ICE Test.

Answer 20

No

Question 21

How is the windshield heated?

Answer 21

Electrically heated with sensors up to the edge of a heating mat.

Question 22

How many layers of windsheild panels do we have. Which one is structural and where is heat applied?

Answer 22

1) 2 layers
2) Inner is structural
3) Heating element is between the two layers.

Question 23

What should you do if your inner windshield develops a crack in flight?

Answer 23

Descend, Depresurize and Don Goggles ASAP (checklist in QRH).