Systems -Ice and Rain Protection Flashcards
(23 cards)
How is the overhead Ice Protection Panel laid out?
1) Top Row is Pneuamtically Heated AI
2) Middle Row is Electrically Heated AI
3) Bottom Row controls the pneumatic heating
When do the sensors and probes for windshield heat start heating?
after engine start.
What is required for wing and tail anti ice to activate and why?
At least 25 kts of speed so that they don’t warp from the intense heat from the eng. bleeds.
Does Engine Lip Anti-Ice have any min speed requirements in order to operate?
No.
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?
1) Lip Anti Ice All the time
2) Wing and Tail if:
- above 25 kts
- Ice detector detects ice.
If the ice detection knob is in the AUTO position when will you get A/I protection?
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.
If the Ice detection knob is in the ALL position, what kind of A/I protection do you get?
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.
Should you ever have the Ice protection knob in ALL on the ground?
No, except during test.
What principle does the Ice Detection system work on?
Ultra Sonic Vibration
What happens when a contaminent freezes to the Ice Detectors?
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.
Why does the Ice Detection system shut off the #1 pack under 24,600 feet
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.
What is a PRSOV?
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.
Where are the exit points for Wing A/I Air?
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.
Where is the exit point for the Horizontal Stab air
Vents near the elevator known as the “horn”
When is the “Flight Idle” Anti Ice schedule over-ridden?
Below 15,000ft with gear down
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?
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.
How will the FADEC compensate for thrust loss feeling in case you hit icing conditions after takeoff
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.
How is an Ice Test Conducted?
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.
What EICAS messsages should you see after the Ice Test completes?
ICE - Condition
ICE - detect fail
BABY - Bleed low temp
CROSS BLEED MAYBE - May or may not have an X-Bleed open message.
Should you ever reset or alternate a FADEC after an ICE Test.
No
How is the windshield heated?
Electrically heated with sensors up to the edge of a heating mat.
How many layers of windsheild panels do we have. Which one is structural and where is heat applied?
1) 2 layers
2) Inner is structural
3) Heating element is between the two layers.
What should you do if your inner windshield develops a crack in flight?
Descend, Depresurize and Don Goggles ASAP (checklist in QRH).
