Ice and Rain Control Systems Flashcards
7 cards from real Airframe Mechanic Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Ice and Rain Control Systems flashcards as text
What is the purpose of the piccolo tube (spray tube) in a thermal anti-icing leading edge system?
Answer: To direct hot bleed air through small holes against the inside of the leading edge skin
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.
Rain repellent systems that use a chemical compound on windshields work on which principle?
Answer: Creating a hydrophobic surface that causes water to bead and blow off
Rain repellent compounds create a hydrophobic coating that causes water to bead into droplets that are removed by airflow.
What is the maximum allowable time a deicing boot should remain inflated in a typical inflation/deflation cycle?
Answer: Approximately 6–8 seconds inflation followed by deflation and suction hold-down
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.
When is it appropriate to activate pneumatic deicing boots according to standard operating procedures?
Answer: After a sufficient accumulation of ice (typically 1/4 to 1/2 inch) has formed
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.
Which material is commonly used for the outer surface of pneumatic deicing boots because of its resistance to abrasion and ozone?
Answer: Neoprene rubber
Neoprene (polychloroprene) rubber is widely used for deicing boot outer surfaces due to its good resistance to abrasion, ozone, weathering, and aviation fluids.
What type of ice protection does the engine air inlet of most large turbofan engines rely upon?
Answer: Hot bleed air from an engine stage ducted through the inlet lip
Turbofan engine inlets use hot bleed air ducted through the inlet lip structure to prevent ice formation and protect engine internals.
The term 'SLD' in the context of icing regulations refers to which hazardous icing condition?
Answer: Supercooled Large Droplets
Supercooled Large Droplets (SLD) are a particularly hazardous icing condition because their size allows them to impact areas aft of typical ice protection coverage.