De Ice System

Question 0

Deflectors extended open a small door to…

Answer 0

Eject ice, snow and sand

Question 1

Pneumatic Low Pressure Light activated when

Answer 1

<18 psi, insufficient pressure to inflate boots

PTM 10

Question 2

Deflectors extended ….. And held and released …..

Answer 2

Pneumatically…electromechanically

Question 3

How do you extend the intake deflectors

Answer 3

Ng greater than 75%

Hold EXTEND until EXT indicated the continue to hold for 3-5 seconds

Question 4

How are the intake deflectors retracted

Answer 4

Bleed air further extends the deflector to release pressure off the locking pins, the pins are electrically retracted by solenoid, same pin solenoid de-energizes the bleed air, pirging the pressurized lines to atmosphere.

Question 5

What is the danger of operating the intake deflectors in hot climates

Answer 5

The deflectors block the oil cooler which can cause oil temp overheating hot sandy climates

Question 6

Prop De-Ice

How many elements are there and how long are the heating intervals?

Answer 6

Four
Outer and Inner on Left and Right prop
34 seconds

Question 7

Prop De-Ice

How long until the entire cycle is complete

Answer 7

2 minutes and 16 seconds (34 * 4)

Question 8

Prop-DeIce

Cycling the deice switch will…

Answer 8

Switch to the next element in the sequence

Left Outter, left inner, right outter, right inner

Question 9

Prop De-Ice

deice will stop when the switch is turned off or…

Answer 9

When the oil pressure is below 40psi (prevents overheating when the prop is not turning)

Question 10

Prop De-Ice

After engine failure, will the prop de-ice system still allocate time to the failed side

Answer 10

Yes, although the failed side is not receiving power, the timer will still allocate time to it.

Question 11

Boots

How are the boots of the horizontal stab different than the wings (structurally)

Answer 11

There is a nylon cap between the horizontal stabilizer and the stabilizer boot as reinforcement from ice from the wing colliding with the stab.

Question 12

Dual Pressure Switch

What will happen with cabin heat in AUTO and pressure below 25psi

Answer 12

The dual pressure switch will stop further opening of the hot air valve.

Question 13

Dual Pressure Switch

What will happen with cabin heat in AUTO and the pressure falls below 20psi

Answer 13

Hot air valve will close

Question 14

What is the function of the ejector near the horiz stab?

Answer 14

The ejector uses bleed air to create a vacuum, holding the boots tight to the leading edge of the wing and hoz stab.

Question 15

What is the function of the distribution valve?

Answer 15

The three valves (one for each wing plus for the stab) takes signal from the timer to switch each boot between pressure from the bleed air (inflate) and suction from the ejector (deflate).

Question 16

What is the boot timing for FAST and SLOW

Answer 16

One minute cycles (each boot) and Three minutes cycles.

Question 17

What is the purpose of the valve heater

Answer 17

To prevent freezing of bleed air condensation in the distribution valve. Remember the air condenses through a heat exchanger before it gets to the boots.

Question 18

What are inflation times for the wing and stab boots

Answer 18

5 seconds and 3 seconds

Question 19

What is the dwell time in FAST and SLOW

Answer 19

44 and 164 seconds

Question 20

What is the nulling function of the boots

Answer 20

When turned off, then on the boots will start the cycle of the next boot in the sequence

Question 21

What does the stab boot lights indicate

Answer 21

The pressure is being supplied to the boots, it does not insure operation

Question 22

Stab boot activation with flaps

How many times will the stab boots inflate with flaps 5-12 degrees

Answer 22

Twice, only with bleeds on and boots are off

Question 23

Stab boot activation with flaps

How many times will the stab boots inflate with >17 degrees

Answer 23

An additional two, only with bleeds on and boots are off

Question 24

What will happend when using the wipers >100 kts

Answer 24

They may not park and possibly pop the circuit breaker

Question 25

What are the limitations on windshield heat

Answer 25

Never run it on the ground unless taxi before takeoff into icing conditions.

Must be left on in icing conditions

Question 26

Why should you avoid anti-collision lights on with the boots on auto

Answer 26

the strobe can interfere with the boot’s timer

Question 28

What are the 6 operating limitations of the de-ice system

Answer 28

1. All de-ice systems must be fully operative
2. Boots must be operated prior to flap extension
3. Ng MUST be above 75% Ng
4. Do not extend flaps >10 degrees
5. Extend intake deflectors in icing
6. Intentional flight into Severe icing is prohibited