10. Ice And Rain Protection

Question 1

What is the minimum OAT to operate deice boots?

Answer 1

-40 deg C

Question 2

What is the time cycle for SINGLE deice boot inflation?

Answer 2

6 seconds wings, then 4 seconds tail

Question 3

What does the MANUAL position for deice boot inflation do?

Answer 3

Inflates all boots simultaneously for as long as the switch is held

Question 4

Does loss of an engine affect deice boot operation?

Answer 4

No. The loss of one engine’s pneumatic pressure will not affect boot operation.
There is a check valve in the bleed line from each engine to prevent pressure loss

Question 5

Is electrical power required for operation of boot system?

Answer 5

Yes, but with electrical power loss, the vacuum will hold them tightly against leading edge

Question 6

How can it be confirmed that brake deice valves are opening or closing correctly?

Answer 6

By observing a slight increase or decrease in ITT (about 20deg C) when BRAKE DEICE is cycled.

Question 7

During ground operation, simultaneous use of brake deice and wing boots can cause red BLEED AIR FAIL. Why is this?

Answer 7

The substantial drop is pneumatic pressure can cause it to flash momentarily, though light should

Question 8

What is the minimum power on each engine to maintain proper boot inflation if brake heating is on?

Answer 8

85%

Question 9

Which system is the single biggest use of engine bleed air, and can cause rudder boost to be inoperative in an engine failure?

Answer 9

Brake deice

Question 10

What heat is the windshield normally heated to?

Answer 10

95-105deg F

Question 11

What is the difference between normal and high windshield heating?

Answer 11

Normal supplies heat to the broadest area. High supplies a higher intensity of heat to a smaller but more essential viewing area

Question 12

Can windshield heat be used anytime?

Answer 12

Yes. It is protected from overheating by thermal sensors.
It also causes erratic compass indications and possibly distorted visual cues

Question 13

What is the AUTO prop heat sequence on later models approx BB-900 onwards?

Answer 13

90 seconds entire right prop, 90 seconds entire left prop, cycling continuously

Question 14

What does MANUAL prop heat do?

Answer 14

Spring loaded switch supplies current to both props at once. PROP AMPS ammeter does not register flow on manual, however it can be observed on loadmeters

Question 15

How is stall warning heat affected by left landing gear squat switch?

Answer 15

Current flow to heater is minimal while on the ground and full in flight

Question 16

If an amber ENG ANTI-ICE annunciator comes on what is the cause? (Instant and after a short period).

Answer 16

Instantly on indicates loss of electrical power to system.
Delayed illumination indicates an inoperative actuator

Question 17

What considerations should be taken when using manual ice vane system?

Answer 17

160kts or less to reduce forces opposing manual operation (can resume speed once positioned). Electric switch should match manual handle position to give correct annunciator indication (provided circuit breaker has already been pulled via the checklist)

Question 18

How is brake deice turned off after gear retraction?

Answer 18

A 10 minute timer starts on retraction. Brake de ice annunciator should be monitored and if still on after about 10 minutes system should be manually turned off

Question 19

What speed is necessary to prevent ice formation under wing?

Answer 19

140kias

Question 20

What speed does the effectiveness of the windshield heating system limit aircraft to?

Answer 20

226kias

Question 21

What should the PROP AMPS ammeter read? (4 blade)

Answer 21

18-24 amps

Question 22

What effect will ice vane extension have on propellor blade angle?

Answer 22

Blade angle will decrease slightly (move to a finer pitch).

Since the activation of Engine Anti-Ice causes a power reduction and in turn an airspeed reduction, both results would cause a fixed-pitch propeller to slow down. Hence, the PPG will decrease the blade angle to keep the propeller speed from decreasing.