Airframe Mechanic Certification Ice and Rain Control Systems 4

Question 1

What is the purpose of the piccolo tube (spray tube) in a thermal anti-icing leading edge system?

Accepted Answer

To direct hot bleed air through small holes against the inside of the leading edge skin

Answer

The piccolo tube has small holes that direct jets of hot bleed air against the inner surface of the leading edge skin for uniform heating.

Question 2

Rain repellent systems that use a chemical compound on windshields work on which principle?

Accepted Answer

Creating a hydrophobic surface that causes water to bead and blow off

Answer

Rain repellent compounds create a hydrophobic coating that causes water to bead into droplets that are removed by airflow.

Question 3

What is the maximum allowable time a deicing boot should remain inflated in a typical inflation/deflation cycle?

Accepted Answer

Approximately 6–8 seconds inflation followed by deflation and suction hold-down

Answer

Typical boot cycles inflate for about 6–8 seconds to crack and shed ice, then deflate with suction applied to hold the boot flat and reduce aerodynamic drag.

Question 4

When is it appropriate to activate pneumatic deicing boots according to standard operating procedures?

Accepted Answer

After a sufficient accumulation of ice (typically 1/4 to 1/2 inch) has formed

Answer

Manufacturers typically recommend allowing a minimum ice build-up before cycling boots so the ice layer is thick enough to be broken and shed effectively.

Question 5

Which material is commonly used for the outer surface of pneumatic deicing boots because of its resistance to abrasion and ozone?

Accepted Answer

Neoprene rubber

Answer

Neoprene (polychloroprene) rubber is widely used for deicing boot outer surfaces due to its good resistance to abrasion, ozone, weathering, and aviation fluids.

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Ice and Rain Control Systems 4