Ice and Rain Protection Systems

Question 1

Which probe heats are monitored and what would you see if failed? How do you know which one failed?

Answer 1

-The first 6 starting with CAPT PITOT (rotating clockwise)

PITOT/STALL HEATER OFF annunciator illuminates
Check for one that doesn’t have a current running

Question 2

When is Tail deice required?

Answer 2

• every 20 mins while in icing conditions
• 1 min prior to selecting landing flaps
• prior to turning off airfoil ice protection

(Every 20 mins and prior to turning off requirements only required with 2 switch manual system, 1 switch system automatically does it)

Question 3

What are the differences between the 1 switch and the 2 switch AIR FOIL ice protection

Answer 3

2 switch:
-when either switch is ON, the ice protection regulator valve will open and the respective augmentation valve is armed for temperature mode

1 switch:
-when the switch is ON, the ice protection valve opens and the pneumatic crossfeed valve must be opened to arm the respective augmentation valves for temperature mode

Question 4

Which has priority, Temperature or Pressure?

Answer 4

Temperature

Question 5

How do we turn on ice protection?

Answer 5

1. ) Ignition= ON/Continuous (A or B with rotary switch)
2. ) Engine Anti-ice switche(s)= ON (EPR drops then stabilizes, L/R ENG VALVE flashes then blue L/R ENG ANTI ICE illuminates)
3. ) Pneumatic Crossfeed Levers= Open
4. ) Airfoil Anti-ice switches= ON (ICE PROTECT TEMP LOW flashes on until hot enough temp is sensed, then blue WING ANTI ICE ON illuminates)
5. )Ignition= OFF

To turn system off, go in reverse order

Question 6

What annunciators illuminate when turning on the airfoil anti?

Answer 6

• L/R ICE PROT TEMP LOW momentarily until temperature in pneumatic center manifold increases
• Blue WING ANTI ICE ON annunciator illuminates