Chapter 13 - Airframe Ice and Rain Control - Oral Questions

Question 1

What controls the temperature in a thermal anti-icing system?

Answer 1

Hot and cold air are mixed

Question 2

What are the sources of heat for thermal anti-icing systems?

Answer 2

Bleed air from the compressor section of a turbine engine,

engine exhaust heat exchangers,

and combustion heaters

Question 3

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

Answer 3

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

Question 4

What happens to the hot air used by a thermal anti-ice system after it has heated the surface?

Answer 4

The air is dumped (exhausted) overboard

Question 5

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

Answer 5

The air is hot enough to cause damage to the aircraft structure

Question 6

What are the effects of arcing on an electrically heated windshield?

Answer 6

Localized overheating and damage to the windshield

Question 7

Can the operation of an electrically heated pitot-tube be checked with the aircraft’s ammeter, and if so, how?

Answer 7

Yes, turn on the pitot heater and watch the deflection of the ammeter needle

Question 8

Describe several potential problems associated with electrically heated windshields

Answer 8

Arcing, delamination, scratches, discoloration

Question 9

Why do some pneumatic deicer boot systems have and electrically operated timer?

Answer 9

To automatically cycle the boots, provide the proper rest time, then recycle the boots

Question 10

What are the two common methods of inflating deicer boots?

Answer 10

Bleed air from a turbine engine, and

exhaust from an engine driven vacuum pump

Question 11

What procedure is used to hold deicer boots flat with the airfoil surface during flight?

Answer 11

Suction is applied to the boots

Question 12

Why do some deicer boot systems incorporate an oil separator?

Answer 12

If a wet pump system is used, the oil must be removed before it reaches the boots because it would damage the rubber

Question 13

What methods are used to attach a deicer boot to the leading edges of the wing and tail surfaces?

Answer 13

Adhesives,

fairing strips and screws, or

a combination

Question 14

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

Answer 14

Consult the service manual and follow instructions

Question 15

Describe the methods commonly used to remove rain from a windshield

Answer 15

Windshield wipers,

a blast of air, or

chemical rain repellant

Question 16

What power sources are used to operate windshield wipers?

Answer 16

Electric or Hydraulic

Question 17

Name two problems associated with in-flight operation of aircraft windshield wipers

Answer 17

Insufficient blade pressure caused by aerodynamic forces and

failure to oscillate fast enough

Question 18

Describe the operation of a pneumatic rain removal system

Answer 18

A high velocity air blast prevents the rain from reaching the windshield

Question 19

What are the effects of spraying rain repellant on a dry windshield?

Answer 19

It smears and streaks, reducing visibility, and is hard to remove when dry

Question 20

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

Answer 20

In reference material provided by the manufacturer