Ice and Rain Control Systems

Question 1

What methods are used to supply heat for thermal anti-icing systems?

Answer 1

Turbine compressor hot air, engine exhaust heaters and ram air heated by a combustion heater

Question 2

How is the temperature maintained in a thermal anti-icing system?

Answer 2

By mixing heated air with ambient air

Question 3

What happens to the thermal anti-icing airflow after it has heated a leading edge surface?

Answer 3

The airflow is exhausted to the atmosphere

Question 4

How could an electrically heated Pitot tube with an ammeter installed in the system be check for operation?

Answer 4

It could be verified by noting the current consumption when the heater is turned on

Question 5

What are two methods of inflating pneumatic deicer boots?

Answer 5

An engine driven vacuum pump and bleed air from a turbine engine compressor

Question 6

What normally keeps deicer boots held down in flight?

Answer 6

Suction is supplied to the boots during the flight

Question 7

What is the function of the oil separator used in some deicer boots systems?

Answer 7

It removes oil before it reaches the boots that could damage the rubber

Question 8

How are deicer boots attached to the leading edges of wing and tail surfaces?

Answer 8

Bonding, fairing strips and screws, or a combination of both

Question 9

What must be accomplished to a deicer boot prior to a cold patch repair?

Answer 9

Relieve the installed tension

Question 10

What is the purpose of the electronic timer in a pneumatic deicer boot system?

Answer 10

It controls the operating sequence and time intervals

Question 11

Why is a windshield rain repellent system not operated when the windshield is dry?

Answer 11

Reduces visibility and it’s hard to remove dry

Question 12

Name at least two methods used to remove rain from a windshield?

Answer 12

Windshield wipers, pneumatic blast, chemical rain repeller, hydrophobic seal coating

Question 13

What powers windshield wiper systems?

Answer 13

Electrical or hydraulic power

Question 14

What are the two inherent problems associated with windshield wipers when operated in flight?

Answer 14

Aerodynamic forces reduce blade pressure and failure to achieve fast enough wiper operations

Question 15

How does a pneumatic rain removal system work?

Answer 15

The air blast breaks the rain drops into small particles that are then blown away

Question 16

What prevents overheating of the leading edges of a thermal anti-ice system operated by engine bleed air?

Answer 16

Overheat sensors signal the anti-icing valves to close and shut off the hot air

Question 17

Why is it necessary to provide overheat protection for anti-icy systems that use turbine engine bleed air?

Answer 17

The air is too hot and can damage the aircraft structure

Question 18

What are the effects of arcing on electrical heated windshield?

Answer 18

Localized overheating and damage to the windshield

Question 19

Describe several potential problems associated with electrically heated windshields

Answer 19

Arcing, delamination, scratches and discoloration

Question 20

What important steps should be taken prior to making a cold patch repair to a deicer boot?

Answer 20

Consult the manufacturers service manual

Question 21

Where would you find information on the acceptable limits of windshield delamination?

Answer 21

In the reference material, provided by the manufacture