DONE 3N Airplane Systems - De-icing, Anti-icing

Question 0

• AIRPLANE ONLY*

1. What is the difference between a deice system and an anti-ice system? (FAA-H-8083-31)

Answer 0

A deice system is used to eliminate ice that has already formed. An anti-ice system is used to prevent the formation of ice.

Question 1

• AIRPLANE ONLY*

2. What types of systems are used in the prevention and elimination of airframe ice? (FAA-H-8083-31)

Answer 1

Pneumatic—A deice type of system; consists of inflatable boots attached to the leading edges of the wings and tail surfaces. Compressed air from the pressure side of the engine vacuum pump is cycled through ducts or tubes in the boots causing the boots to inflate. Most systems also incorporate a timer.
Hot Air—An anti-ice type system; commonly found on turboprop and turbojet aircraft. Hot air is directed from the engine (compressor) to the leading edges of the wings.

Question 2

• AIRPLANE ONLY*

3. What types of systems are used in the prevention and elimination of propeller ice? (FAA-H-8083-31)

Answer 2

Electrically heated boots—Consist of heating elements incorporated into the boots which are bonded to the propeller. The ice buildup on the propeller is heated from below and then thrown off by centrifugal force.
Fluid system—Consists of an electrically driven pump which, when activated, supplies a fluid, such as alcohol, to a device in the propeller spinner which distributes the fluid along the propeller assisted by centrifugal force.

Question 3

• AIRPLANE ONLY*

4. What types of systems are used in the prevention and elimination of windshield ice? (FAA-H-8083-31)

Answer 3

Fluid system—Consists of an electrically-driven pump which may be activated to spray a fluid, such as alcohol, onto the windshield to prevent the formation of ice.
Electrical system—Heating elements are embedded in the windshield or in a device attached to the windshield which when activated, prevents the formation of ice.