Ice & Rain Control Systems

Question 1

1. Describe the operating principle of inflatable devices boots.

Answer 1

Pneumatic air inflates & deflates rubber boots attached to leading edge of wing & stabilizers. Alternating cycle inflate & deflate. Breaks ice away from wing both wings operate at same time

Question 2

2. Why is it critical to prevent the formation of ice on aircraft wings and control surfaces?

Answer 2

Distorts airfoil shape reduces lift increases weight & stress

Question 3

3. What are two methods of inflating pneumatic deliver boots?

Answer 3

Pressurized air from engine driven pump(vacuum) or bleed air from turbine engine compressor

Question 4

4. What methods are used to attach devices boots to the leading edges of wing and tail surfaces?

Answer 4

Bonding to surface with cement, fairing strips and or screws

Question 5

5. What is the purpose of an air oil separator in a pneumatic driving system?

Answer 5

Removing oil & preventing deterioration of deice boots

Question 6

6. What is used to clean devices boots?

Answer 6

Mild soap & water

Question 7

7. What must be done before you make a cold patch repair to a driver boot?

Answer 7

Clean, fought the surface of the boot & patch, glue & attach

Question 8

8. What component of a pneumatic decider system normally allows suction to be supplied to the boots to hold them down in flight?

Answer 8

Solenoid distributor valve

Question 9

9. Describe the operating principle for thermal anti-icing systems?

Answer 9

Hot air passed though the space between skins, and heat is sufficient to prevent formation of ice or melt any next to the skin

Question 10

10. How can you determine if the heater in a pitot is working?

Answer 10

Turn on feel for heat

Question 11

11. What methods are used to supply heated air for thermal anti-icing system?

Answer 11

Bleed air from turbine engine compressor
Engine exhaust heat exchangers
Ram air heated by combustion heater

Question 12

12. how is overheating prevented in a thermal anti-icing system using bleed air?

Answer 12

Thermal switch will close the shut-off valve when temps get to 185F then shut off valve will open when temp drops

Question 13

13. What is the purpose of the de-ice boot electrical timers?

Answer 13

To inflate boots symmetrically and electrically each boot individually preventing overload Electrical system

Question 14

14. In a thermal anti-icing system, what happens to the air after it has heated the leading edge of the wing?

Answer 14

Exhausted to atmosphere at wing tip

Question 15

15. What problems are associated with electrically heated windshields?

Answer 15

Delaminating
Arcing
Scratches
Discoloration

Question 16

16. What is windshield delimitation?

Answer 16

Separation of plies

Question 17

17. What does arcing usually indicate in an electrically heated windshield?

Answer 17

Indicates breakdown in conductive coating

Question 18

18. Name the three methods of removing train from aircraft wiper systems.

Answer 18

Wipers
Pneumatic systems
Chemical repellant

Question 19

19. What type of power is used to operate windshield wiper systems?

Answer 19

Electrical or hydraulic

Question 20

20. What are common problems encountered with windshield wipers?

Answer 20

Aerodynamic forces hits wiper blades reducing the blade pressure on windshield
Fast enough wiper oscillation

Question 21

21. How does a pneumatic rain removal system work?

Answer 21

High pressure air blown across windshields prevents rain from hitting windshield

Question 22

22. Why should your windshield wipers not be operated when the windshield wipers are dry?

Answer 22

Scratch glass